JP4360655B1 - Image signal correction method - Google Patents

Abstract

In a person suffering from first color blindness, dark red R = 255, G = 0, and B = 0 appear almost black and cannot be distinguished from black. In addition, warm greenish green is almost difficult to distinguish from brown.
When the input signal is dark red, red mixed with a little white R = 255, G = 51, B = 51, or vermilion R = 255 near the short wavelength (orange), G = 51, B = Correction is performed by a control signal generation means for controlling the magnitude of the correction signal value in the subsequent stage for correcting to 0, a correction signal generation means for generating a correction signal, and a correction means for correcting and outputting the input signal by the correction signal. An image signal correcting means operating method characterized in that an image signal is provided that is less likely to be uncomfortable even by a healthy person.
[Selection] Figure 1

Description

  The present invention relates to a signal correction method for an image signal used in a display device or the like.

In a conventional display device, a process for faithfully reproducing the color of a subject is performed using an R (red) signal, a G (green) signal, and a B (blue) signal which are three primary color signals.
Further, although it has been possible to adjust a desired color as an image quality adjustment process, correction is performed at a certain rate, a specific color is converted into a specific color, or the like.
Note that there are R signal, G signal, B signal, Y (luminance signal), CbCr (color) signal and the like as image signals generally adopted in the display device. As a way of expressing these R signal, G signal, B signal, etc., as an example expressed in digital, it is expressed as 0 to 255 when expressed in 8 bits, a real number from 0 to 1 when expressed as analog, and further expressed as 0% to 100%, etc. There is a way. Furthermore, it is standardized to represent a wider color gamut, such as the xvYCC standard. That is, a color gamut represented by a negative real number of 0 or less or a real number of 1 or more is also used.
In the following description, unless otherwise specified, 0 to 255, which is quantized with digital 8 bits, is used. The numbers after the decimal point are rounded and expressed as an integer.

It is preferable for a general color vision person who is a healthy person to faithfully reproduce the image signal including the R signal, the G signal, and the B signal, which are the three primary color signals.
However, it is not always good to reproduce color faithfully for those who suffer from color blindness. For example, a person suffering from the first color blindness looks almost black in dark red (R = 255, G = 0, B = 0). In addition, green has a variety of colors, from a warm yellowish green to a bluish cold green. Among them, warm-colored dark green is almost indistinguishable from brown for people with color blindness. A bright green, brownish brown, may appear brown to people with color blindness. The deep greens of Japanese broad-leaved forests are indistinguishable from brown.
In addition, for those suffering from third color blindness, dark blue appears almost black.
The dark color means a pure color that does not include other color components other than the color.
In addition, referring to pre-registered information on color blindness and colors that tend to be mistaken for color-blind people, it is judged whether the input image data contains a color that causes a misidentification, and the color of the image data is changed to a predetermined color. There is a device to convert.
Further, when the desired color signal is smaller than the desired reference signal value, the correction signal generated according to the desired color signal value and another color signal value other than the desired color signal is used to determine the desired color signal. There is an idea to make corrections.

JP 11-175050 A JP 2000-306074 PR Japanese Patent No. 4139433 International Publication No. 2008/032528 Japanese Patent Application No. 2006-157301

It is preferable for a healthy person to faithfully reproduce an image signal composed of an R signal, a G signal, and a B signal, which are three primary color signals. However, it is not always good to reproduce color faithfully for those who suffer from color blindness.
For example, a person suffering from the first color blindness in which the red cone does not function, dark red (R = 255, G = 0, B = 0) appears almost black. This dark red is not used, but bright red (R = 255, G = 51, B = 51) mixed with a little white or vermilion (R = 255, G = 51, B = 0) closer to the short wavelength (orange) ) Makes it possible to stimulate green and blue vision materials even with the same red color, and can be distinguished from black. For example, a bright red character in a black character string is emphasized, and the character can be read even in a dark background.
In addition, those who suffer from the first color blindness whose red cones do not function have a variety of colors ranging from warm yellowish green to bluish cold green, among which warm warm dark green is , Almost indistinguishable from brown. The brownish green, which is a brilliant green, may appear pure brown. The deep greens of Japanese broad-leaved forests are indistinguishable from brown. On the other hand, green with a strong bluish color, like the green on the road sign, is unlikely to be mistaken for brown. In addition, bright green may be mistaken for yellow or red if it is a warm color, but it is difficult to make a mistake if the bluish color is strong. Road signs and traffic signals must be limited to the same green but bluish.
Furthermore, those with third color blindness, whose blue cones do not function, appear dark blue almost black. By using bright blue (R = 51, G = 51, B = 255) with a little white mixed without using this dark blue, it is possible to stimulate green and red vision materials even with the same blue color. , Separation from black becomes possible. For example, a light blue character in a black character string is emphasized, and the character can be read even in a dark background.
On the other hand, emphasizing and mixing color components that are difficult to see as described above makes it easier for a person with color blindness to see, but conversely, a healthy person feels uncomfortable. Therefore, it is important how much emphasis should be given and in what range. However, sufficient consideration has not been made so far, and a processing method for automatically carrying out such consideration has not been realized. It wasn't.
The present invention has been made in view of the above circumstances, and can be corrected and displayed in an image that is easy to see for a visually ill person, and can also be displayed with less discomfort for a healthy person. An object of the present invention is to provide a signal correction method for a display device.

  In the present invention, when correcting a desired color signal among the R signal, G signal, and B signal, which are the three primary color signals of the image signal, the desired color signal value and the color signal value other than the desired color signal are obtained. A correction signal is generated, and the amount of correction is controlled by the control signal generated from the color signal values other than the two colors and the desired reference signal value, and the input image signal is corrected. The most important feature. Details are shown below.

According to the first aspect of the present invention, an R input terminal, a G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal, which are three primary color signals,
B reference signal generating means for generating and outputting a desired B reference signal for the B signal;
G reference signal generating means for generating and outputting a desired G reference signal for the G signal;
B control signal generating means connected to the B input terminal and generating a B control signal based on an input B signal and a B reference signal value, and outputting the B control signal to a subsequent stage;
G control signal generating means connected to the G input terminal and generating a G control signal based on an input G signal and a G reference signal value;
G connected to the R input terminal, the G input terminal, and the B control signal generating means, generates a G correction signal for the G signal based on the input R signal, G signal, and B control signal, and outputs the G correction signal to the subsequent stage. Correction signal generation means;
B connected to the R input terminal, the B input terminal, and the G control signal generation means, generates a B correction signal for the B signal based on the input R signal, B signal, and G control signal, and outputs the B correction signal to the subsequent stage. Correction signal generation means;
G correction means connected to the G input terminal and G correction signal generation means, for correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The B control signal generating means does not generate a B control signal when the B signal value is larger than the B reference signal value, and generates a B control signal when the B signal value is smaller than the B reference signal value. The B control signal generates a B control signal that is inversely proportional to the B signal value and proportional to a difference value between the B signal value and the B reference signal value;
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The G correction signal generation means does not generate a G correction signal when the R signal value is smaller than the G signal value multiplied by the desired coefficient GK1, and the R signal value increases the G signal value by the desired coefficient GK1. If it is greater than the value, a G correction signal is generated,
The G correction signal is generated as the R signal value is larger or the G signal value is smaller. Conversely, the G correction signal is generated as the R signal value is smaller or the G signal value is larger. The signal value is small, that is, proportional to the R signal value and inversely proportional to the G signal value, and further, the correction signal value and the correction range are determined from the relationship between the R signal value and the G signal value by the coefficient GK1. The operation result to be adjusted
The magnitude is adjusted by dividing by the desired coefficient GK2, and the magnitude of the value is further controlled by the B control signal, that is, G is inversely proportional to the desired coefficient GK2 and proportional to the B control signal. Generating a correction signal;
When the B correction signal generation means is smaller than the value obtained by multiplying the B signal value by the desired coefficient BK1, no B correction signal is generated, and the R signal value is multiplied by the desired coefficient BK by the B signal value. If greater than the value, generate a B correction signal,
The B correction signal is generated as the R signal value is larger or the B signal value is smaller. Conversely, the B correction signal is generated as the R signal value is smaller or the B signal value is larger. The signal value becomes smaller, that is, proportional to the R signal value and inversely proportional to the B signal value, and further, the correction signal value and the correction range are determined from the relationship between the R signal value and the B signal value by the coefficient BK1. The operation result to be adjusted
The magnitude is adjusted by dividing by the desired coefficient BK2, and the magnitude of the value is further controlled by the G control signal, that is, B is inversely proportional to the desired coefficient BK2 and proportional to the G control signal. Generating a correction signal;
A step in which the G correction means performs correction by adding the G correction signal to the input G signal, and outputs the corrected G signal;
A step in which the B correction means performs correction by adding the B correction signal to the input B signal, and outputs the corrected B signal;
The image signal correcting method of the image signal correcting means is characterized in that

According to the present invention, when the G signal is corrected, according to the B control signal generated based on the B signal value and the B reference signal value, the correction signal generated based on the R signal value and the G signal value, Correction can be performed by changing the correction amount.
This corrects only dark red, generates a G correction signal that tends to be proportional to the R signal value and inversely proportional to the G signal value or the B signal value. A correction added to the signal is performed to change the appearance of red. That is, as the R signal value, which is dark red, increases, or as the G signal value or B signal value decreases, a larger correction amount of G correction signal is added. Conversely, the smaller the R signal value, or the larger the G signal value or B signal value, the smaller the correction amount. Further, if the B signal is greater than the desired reference signal value, no correction signal is generated.
When the B signal is corrected, the correction amount is changed according to the G control signal generated based on the G signal value and the G reference signal value, the correction signal generated based on the R signal value, and the B signal value. Can be corrected.
As a result, only the dark red is corrected, and a B correction signal that tends to be proportional to the R signal value and is inversely proportional to the G signal value or the B signal value is generated. A correction added to the signal is performed to change the appearance of red. That is, as the R signal value, which is dark red, increases, or as the G signal value or B signal value decreases, a B correction signal with a larger correction amount is added. Conversely, the smaller the R signal value, or the larger the G signal value or B signal value, the smaller the correction amount. Further, if the G signal is greater than the desired reference signal value, no correction signal is generated.
Therefore, when R signal = 255, G signal = 0, and B signal = 0, which are dark red, are input, for example, R signal = 255, G signal = 51, B signal, which is red mixed with a little white. = 51, red signal near the short wavelength (orange) R signal = 255, G signal = 51, B signal = 0, red mixed with a little blue, R signal = 255, G signal = 0, The B signal can be corrected to 51 or the like.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate, and the G signal or B signal is not corrected in the area that is greater than the desired reference signal value, the healthy person also feels uncomfortable. An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

The invention according to claim 2 is an R input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals, a G input terminal, and a B input terminal;
R reference signal generating means for generating and outputting a desired R reference signal for the R signal;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value, and outputting the R control signal to a subsequent stage;
B connected to the G input terminal, the B input terminal, and the R control signal generation means, generates a B correction signal for the B signal based on the input G signal, B signal, and R control signal, and outputs the B correction signal to the subsequent stage. Correction signal generation means;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G input terminal;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
When the B correction signal generating means is smaller than the value obtained by multiplying the B signal value by the desired coefficient BK1, no B correction signal is generated, and the G signal value is multiplied by the desired coefficient BK by the B signal value. If greater than the value, generate a B correction signal,
The B correction signal is generated as the G signal value is larger or the B signal value is smaller. On the contrary, as the G signal value is smaller or the B signal value is larger, the correction signal is generated. The value is small, that is, proportional to the G signal value and inversely proportional to the B signal value, and the correction signal value and the correction range are adjusted by the relationship between the G signal value and the B signal value by the coefficient BK1. The operation result
The magnitude is adjusted by dividing by the desired coefficient BK2, and the magnitude of the value is further controlled by the R control signal, that is, B is inversely proportional to the desired coefficient BK2 and proportional to the R control signal. Generating a correction signal;
A step in which the B correction means performs correction by adding the B correction signal to the input B signal, and outputs the corrected B signal;
The image signal correcting method of the image signal correcting means is characterized in that

According to the present invention, when the B signal is corrected, according to the R control signal generated based on the R signal value and the R reference signal value, and the correction signal generated based on the G signal value and the B signal value. Can be corrected by changing the correction amount.
This corrects only dark green, generates a B correction signal that tends to be proportional to the G signal value and inversely proportional to the R signal value or the B signal value. A correction is added to the signal to change the appearance of green. That is, as the G signal value, which is dark green, increases, or as the R signal value or B signal value decreases, a B correction signal with a larger correction amount is added. Conversely, the smaller the G signal value, or the larger the R signal value or B signal value, the smaller the correction amount. Further, if the R signal is greater than the desired reference signal value, no correction signal is generated.
Accordingly, when R signal = 0, G signal = 255, and B signal = 0, which are dark green, are input, for example, R signal = 0, G signal = 255, B signal, which is green mixed with a little blue. = 51 etc. can be corrected.
For this reason, since a person suffering from the first color blindness is effectively corrected in a hard-to-see area that is difficult to discriminate and is not corrected in an area where the R signal is equal to or higher than a desired reference signal value, a sense of discomfort is reduced even for a healthy person. An image signal correction method that makes it possible to achieve compatibility with other things is executed.

The invention according to claim 3 is an R input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal, which are three primary color signals, a G input terminal, and a B input terminal;
G reference signal generating means for generating and outputting a desired G reference signal for the G signal;
R reference signal generating means for generating and outputting a desired R reference signal for the R signal;
G control signal generating means connected to the G input terminal and generating a G control signal based on an input G signal and a G reference signal value;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value, and outputting the R control signal to a subsequent stage;
The R input terminal, the B input terminal, and the G control signal generating means are connected to generate an R correction signal for the R signal based on the input R signal, B signal, and G control signal, and output to the subsequent stage. Correction signal generation means;
G connected to the G input terminal, the B input terminal, and the R control signal generating means, and generates a G correction signal for the G signal based on the input G signal, the B signal, and the R control signal, and outputs the G correction signal to the subsequent stage. Correction signal generation means;
R correction means connected to the R input terminal and the R correction signal generating means, correcting the R signal input from the R input terminal based on the input R correction signal, and outputting a corrected signal;
G correction means connected to the G input terminal and the G correction signal generating means, correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R correction means;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B input terminal,
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
When the R correction signal generating means has a B signal value smaller than a value obtained by multiplying the R signal value by a desired coefficient RK1, no R correction signal is generated, and the B signal value is obtained by multiplying the R signal value by a desired coefficient RK1. If it is greater than the value, an R correction signal is generated,
The correction signal value generated as the B signal value increases or the R signal value decreases as the R correction signal increases. Conversely, the correction signal value generated as the B signal value decreases or the R signal value increases. Is smaller, that is, proportional to the B signal value and inversely proportional to the R signal value, and the correction signal value and the correction range are adjusted from the relationship between the B signal value and the R signal value by the coefficient RK1. The operation result
The magnitude is adjusted by dividing by the desired coefficient RK2, and the magnitude of the value is further controlled by the G control signal, that is, inversely proportional to the desired coefficient BK2 and proportional to the G control signal. Generating a correction signal;
The G correction signal generation means does not generate a G correction signal when the B signal value is smaller than the value obtained by multiplying the G signal value by the desired coefficient GK1, and the B signal value increases the G signal value by the desired coefficient GK1. If it is larger than the value, a G correction signal is generated,
The G correction signal has a larger correction signal value generated as the B signal value is larger or smaller, and conversely, a correction signal value generated as the B signal value is smaller or the G signal value is larger. Is smaller, that is, proportional to the B signal value and inversely proportional to the G signal value, and further, the correction signal value and the correction range are adjusted from the relationship between the B signal value and the G signal value by the coefficient GK1. The operation result
The magnitude is adjusted by dividing by the desired coefficient GK2, and the magnitude of the value is controlled by the R control signal, that is, inversely proportional to the desired coefficient GK2 and proportional to the R control signal. Generating a correction signal;
A step in which the R correction means performs correction by adding the R correction signal to the input R signal, and outputs the corrected R signal;
A step in which the G correction means performs correction by adding the G correction signal to the input G signal, and outputs the corrected G signal;
The image signal correcting method of the image signal correcting means is characterized in that

According to the present invention, when correcting the R signal, according to the G control signal generated based on the G signal value and the G reference signal value, and the correction signal generated based on the R signal value and the B signal value. Correction can be performed by changing the correction amount.
This corrects only dark blue, generates an R correction signal that tends to be proportional to the B signal value and inversely proportional to the R signal value or the G signal value. A correction added to the signal is performed to change the appearance of blue. That is, the larger the B signal value, which is dark blue, or the smaller the R signal value or G signal value, the larger the R correction signal is added. Conversely, the smaller the B signal value, or the larger the R signal value or G signal value, the smaller the correction amount. Further, if the G signal is greater than the desired reference signal value, no correction signal is generated.
When correcting the G signal, the correction amount is set according to the R control signal generated based on the R signal value and the R reference signal value, and the correction signal generated based on the G signal value and the B signal value. It can be corrected by changing.
This corrects only dark blue, generates a G correction signal that tends to be proportional to the B signal value and is inversely proportional to the R signal value or the G signal value. A correction added to the signal is performed to change the appearance of blue. That is, as the B signal value, which is dark blue, increases, or as the R signal value or G signal value decreases, a larger correction amount of G correction signal is added. Conversely, the smaller the B signal value, or the larger the R signal value or the G signal value, the smaller the correction amount. Further, if the R signal is greater than the desired reference signal value, no correction signal is generated.
Accordingly, when R signal = 0, G signal = 0, and B signal = 255, which are dark blue, are input, for example, R signal = 51, G signal = 51, B signal, which is blue mixed with a little white. = 255, blue signal with a little red mixed, R signal = 51, G signal = 0, B signal = 255, blue signal with a little green mixed, R signal = 0, G signal = 51, B signal = 255 etc. can be corrected.
For this reason, a person suffering from third color blindness is effectively corrected in an area where it is difficult to discern, and an area where the R signal or G signal is greater than a desired reference signal value is not corrected, so that a healthy person also feels strange An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

The invention according to claim 4 is an R input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal, which are three primary color signals, a G input terminal, and a B input terminal;
B control signal generating means connected to the B input terminal and generating a B control signal based on a B signal inputted and a B reference signal value set in advance in advance;
G control signal generating means connected to the G input terminal, for generating a G control signal based on a G signal inputted and a G reference signal value set in advance, and outputting the G control signal to a subsequent stage;
Connected to the R input terminal, the G input terminal, and the B control signal generating means, and based on the R signal, the G signal, the B control signal, and the G reference signal value set in advance in advance, G correction signal generation means for generating a G correction signal and outputting it to a subsequent stage;
Connected to the R input terminal, the B input terminal, and the G control signal generating means, and based on the input R signal, B signal, G control signal, and a B reference signal value set in advance in advance, B correction signal generation means for generating a B correction signal and outputting it to a subsequent stage;
G correction means connected to the G input terminal and G correction signal generation means, for correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The B control signal generating means does not generate a B control signal when the B signal value is larger than the B reference signal value, and generates a B control signal when the B signal value is smaller than the B reference signal value. The B control signal generates a B control signal that is inversely proportional to the B signal value and proportional to a difference value between the B signal value and the B reference signal value;
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The G correction signal generating means does not generate a correction signal when the G signal is larger than the G reference signal value based on the R signal, the G signal, the G reference signal value set in advance and the B control signal. When the G signal is smaller than the G reference signal, a G correction signal is generated,
The G correction signal is proportional to the R signal value, is inversely proportional to the G signal value, is proportional to the difference value between the G signal value and the G reference signal value, and is proportional to the B control signal, And a step in which the calculation is performed with a desired coefficient and the magnitude of the value is adjusted to generate the B correction signal generating means, the R signal, the B signal, a preset B reference signal value, and a G control signal. If the B signal is larger than the B reference signal value, no correction signal is generated. If the B signal is smaller than the B reference signal, a B correction signal is generated.
The B correction signal is proportional to the R signal value, inversely proportional to the B signal value, proportional to the difference value between the B signal value and the B reference signal value, and proportional to the G control signal, And a step of generating by adjusting the magnitude of the value by calculating with a desired coefficient. The G correction unit performs correction by adding the G correction signal to the input G signal, and the corrected G signal is obtained. Output step,
A step in which the B correction means performs correction by adding the B correction signal to the input B signal, and outputs the corrected B signal;
The image signal correcting method of the image signal correcting means is characterized in that

According to the present invention, when the G signal is corrected, it is proportional to the R signal value, inversely proportional to the G signal value, proportional to the difference value between the G signal value and the G reference signal value, and proportional to the B control signal. By generating a G correction signal that is inversely proportional to the B signal value and proportional to the difference value between the B signal value and the B reference signal value, the correction amount is changed according to each value of the R signal, the G signal, and the B signal. To make corrections,
When correcting the B signal, it is proportional to the R signal value, inversely proportional to the B signal value, proportional to the difference value between the B signal value and the B reference signal value, and proportional to the G control signal, that is, to the G signal value. By generating a B correction signal that is inversely proportional and proportional to the difference value between the G signal value and the G reference signal value, correction is performed by changing the correction amount according to each value of the R signal, the G signal, and the B signal. be able to.
Thus, correction is performed only for dark red, and a G correction signal or a B correction signal that tends to be proportional to the R signal value and inversely proportional to the G signal value or the B signal value is generated. Correction for adding the correction signal to the G signal or correction for adding the B correction signal to the B signal is performed to change the appearance of red.
That is, the larger the R signal value, which is dark red, or the smaller the G signal value or B signal value, the larger the G correction signal or B correction signal is added. Conversely, the smaller the R signal value, or the larger the G signal value or B signal value, the smaller the correction amount. Further, if the G signal or B signal is greater than the desired reference signal value, no correction signal is generated. .
Therefore, when R signal = 255, G signal = 0, and B signal = 0, which are dark red, are input, for example, R signal = 255, G signal = 51, B signal, which is red mixed with a little white. = 51, red signal near the short wavelength (orange), R signal = 255, G signal = 51, B signal = 0, R signal = 255, which is red mixed with a little blue, G signal = 0, B It can be corrected to signal = 51 or the like.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate, and the G signal or B signal is not corrected in the area that is greater than the desired reference signal value, the healthy person also feels uncomfortable. An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

The invention according to claim 5 is an R input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal, which are three primary color signals, a G input terminal, and a B input terminal;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value set in advance, and outputting the R control signal to a subsequent stage;
Connected to the G input terminal, the B input terminal, and the R control signal generating means, and based on the input G signal, B signal, R control signal, and a preset B reference signal value, B correction signal generation means for generating a B correction signal and outputting it to a subsequent stage;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G input terminal;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
The B correction signal generation means does not generate a correction signal when the B signal is larger than the B reference signal value based on the G signal, the B signal, the B reference signal value set in advance and the R control signal. When the B signal is smaller than the B reference signal, a B correction signal is generated,
The B correction signal is proportional to the G signal value, inversely proportional to the B signal value, proportional to the difference value between the B signal value and the B reference signal value, and proportional to the R control signal, And a step generated by calculating with the desired coefficient and adjusting the magnitude of the value. The B correction means performs correction by adding the B correction signal to the input B signal, and the corrected B signal is obtained. Output step,
The image signal correcting method of the image signal correcting means is characterized in that

According to the present invention, when the B signal is corrected, it is proportional to the G signal value, inversely proportional to the B signal value, proportional to the difference value between the B signal value and the B reference signal value, and proportional to the R control signal. By generating a B correction signal that is inversely proportional to the signal value and proportional to the difference value between the R signal value and the R reference signal value, the correction amount is changed according to each value of the R signal, the G signal, and the B signal. Correction can be performed.
This corrects only dark green, generates a B correction signal that tends to be proportional to the G signal value and inversely proportional to the R signal value and the B signal value. A correction is added to to change the appearance of green.
That is, as the G signal value, which is dark green, increases, or as the R signal value or B signal value decreases, a B correction signal with a larger correction amount is added. Conversely, the smaller the G signal value, or the larger the R signal value or B signal value, the smaller the correction amount. Further, if the R signal or B signal is greater than the desired reference signal value, no correction signal is generated. .
Accordingly, when R signal = 0, G signal = 255, and B signal = 0, which are dark green, are input, for example, R signal = 0, G signal = 255, B signal, which is green mixed with a little blue. = 51 etc. can be corrected.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate and is not corrected in the area where the R signal or the B signal is equal to or higher than the desired reference signal value, the healthy person also feels strange. An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

The invention according to claim 6 is an R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal, which are three primary color signals,
G control signal generating means connected to the G input terminal, for generating a G control signal based on a G signal inputted and a G reference signal value set in advance, and outputting the G control signal to a subsequent stage;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value set in advance, and outputting the R control signal to a subsequent stage;
Connected to the R input terminal, the B input terminal, and the G control signal generating means, and based on the input B signal, R signal, G control signal, and an R reference signal value set in advance in advance, R correction signal generation means for generating an R correction signal and outputting it to a subsequent stage;
Connected to the G input terminal, the B input terminal, and the R control signal generating means, and based on the input B signal, G signal, R control signal, and a G reference signal value set in advance in advance, G correction signal generation means for generating a G correction signal and outputting it to a subsequent stage;
R correction means connected to the R input terminal and the R correction signal generating means, correcting the R signal input from the R input terminal based on the input R correction signal, and outputting a corrected signal;
G correction means connected to the G input terminal and the G correction signal generating means, correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R correction means;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B input terminal,
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
The R correction signal generating means does not generate a correction signal when the R signal is larger than the R reference signal value based on the B signal, the R signal, the R reference signal value set in advance and the G control signal. When the R signal is smaller than the R reference signal, an R correction signal is generated,
The R correction signal is proportional to the B signal value, inversely proportional to the G signal value, proportional to the difference value between the G signal value and the G reference signal value, and proportional to the G control signal, Further, a step in which the calculation is performed with a desired coefficient and the magnitude of the value is adjusted, and the G correction signal generation means includes a B signal, a G signal, a G reference signal value set in advance, and an R control signal. If the G signal is larger than the G reference signal value, no correction signal is generated. If the G signal is smaller than the G reference signal, a G correction signal is generated.
The G correction signal is proportional to the B signal value, inversely proportional to the G signal value, proportional to the difference value between the G signal value and the G reference signal value, and proportional to the R control signal, And a step generated by adjusting the magnitude of the value by calculating with a desired coefficient. The R correction means performs correction by adding the R correction signal to the input R signal, and the corrected R signal is obtained. Output step,
A step in which the G correction means performs correction by adding the G correction signal to the input G signal, and outputs the corrected G signal;
The image signal correcting method of the image signal correcting means is characterized in that

According to the present invention, when correcting the R signal, it is proportional to the B signal value, inversely proportional to the R signal value, proportional to the difference value between the R signal value and the R reference signal value, and proportional to the G control signal. By generating an R correction signal that is inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value, the correction amount is changed according to each value of the R signal, the G signal, and the B signal. To make corrections,
When correcting the G signal, it is proportional to the B signal value, inversely proportional to the G signal value, proportional to the difference value between the G signal value and the G reference signal value, and proportional to the R control signal, that is, to the R signal value. By generating a G correction signal that is inversely proportional and proportional to the difference value between the R signal value and the R reference signal value, correction is performed by changing the correction amount according to each value of the R signal, the G signal, and the B signal. I can do things.
This corrects only dark blue, and generates an R correction signal or G correction signal that tends to be proportional to the B signal value and inversely proportional to the R signal value or G signal value. Correction of adding the correction signal to the R signal or correction of adding the G correction signal to the G signal is performed to change the appearance of blue.
That is, the larger the B signal value, which is dark blue, or the smaller the R signal value or G signal value, the larger the R correction signal or G correction signal is added. Conversely, the smaller the B signal value, or the larger the R signal value or G signal value, the smaller the correction amount. Further, when the R signal or G signal is greater than the desired reference signal value, no correction signal is generated. .
Accordingly, when R signal = 0, G signal = 0, and B signal = 255, which are dark blue, are input, for example, R signal = 51, G signal = 51, B signal, which is blue mixed with a little white. = 255, blue signal with a little red mixed, R signal = 51, G signal = 0, B signal = 255, blue signal with a little green mixed, R signal = 0, G signal = 51, B signal = 255 etc. can be corrected.
For this reason, a person suffering from third color blindness is effectively corrected in an area where it is difficult to discern, and an area where the R signal or G signal is greater than a desired reference signal value is not corrected, so that a healthy person also feels strange An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

In the present invention, when correcting a desired color signal among the R signal, G signal, and B signal, which are the three primary color signals of the image signal, the desired color signal value and the color signal value other than the desired color signal are changed. A corresponding correction signal is generated, and the magnitude of the correction signal is controlled by a control signal generated from a color signal value other than the two colors and a desired reference signal value, and the input image signal is corrected and output. Since this is the operation method of the image signal correction means to
Only the dark red is corrected, and a G correction signal or B correction signal that tends to be proportional to the R signal value and inversely proportional to the G signal value or the B signal value is generated. The correction of adding to the G signal or the correction of adding the B correction signal to the B signal can be performed to change the appearance of red.
Therefore, when R signal = 255, G signal = 0, and B signal = 0, which are dark red, are input, for example, R signal = 255, G signal = 51, B signal, which is red mixed with a little white. = 51, red signal near the short wavelength (orange), R signal = 255, G signal = 51, B signal = 0, R signal = 255, which is red mixed with a little blue, G signal = 0, B It can be corrected to signal = 51 or the like.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate, and is not corrected in the area where the G signal or the B signal is higher than the desired reference signal value, the healthy person also feels uncomfortable. Therefore, it is possible to execute an image signal correction method that makes it possible to achieve both reduction in the size of the image signal.
Furthermore, correction is performed only for dark green, and a B correction signal that tends to be proportional to the G signal value and inversely proportional to the R signal value or the B signal value is generated, and this B correction signal is converted into the B signal. It is possible to change the appearance of green by performing additional correction.
Accordingly, when R signal = 0, G signal = 255, and B signal = 0, which are dark green, are input, for example, R signal = 0, G signal = 255, B signal, which is green mixed with a little blue. = 51 etc. can be corrected.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate and is not corrected in the area where the R signal or the B signal is equal to or higher than the desired reference signal value, the healthy person also feels uncomfortable. Therefore, it is possible to execute an image signal correction method that makes it possible to achieve both reduction in the size of the image signal.
Furthermore, correction is performed only for dark blue, and an R correction signal or a G correction signal that tends to be proportional to the B signal value and is inversely proportional to the R signal value or the G signal value is generated. Correction of adding a signal to the R signal or correction of adding a G correction signal to the G signal can be performed to change the appearance of blue.
Accordingly, when R signal = 0, G signal = 0, and B signal = 255, which are dark blue, are input, for example, R signal = 51, G signal = 51, B signal, which is blue mixed with a little white. = 255, blue signal with a little red mixed, R signal = 51, G signal = 0, B signal = 255, blue signal with a little green mixed, R signal = 0, G signal = 51, B signal = 255 etc. can be corrected.
For this reason, a person suffering from third color blindness is effectively corrected in an area where it is difficult to discern, and an area where the R signal or G signal is higher than the desired reference signal value is not corrected, so that a healthy person also feels uncomfortable. Therefore, it is possible to execute an image signal correction method that makes it possible to achieve both reduction in the size of the image signal.

It is a block diagram explaining the structure of the image signal correction | amendment means 10 of the embodiment which concerns on this invention. Example 1 It is a block diagram explaining the structure of the image signal correction | amendment means 10A of the embodiment which concerns on this invention. (Example 2) It is a block diagram explaining the structure of the image signal correction | amendment means 10B of the embodiment which concerns on this invention. (Example 3) It is a figure of the example of the representative value showing the relationship of the output signal after correction | amendment with respect to the input signal before correction | amendment of Example 1 which concerns on this invention. It is a figure of the example of the representative value showing the relationship of the output signal after correction | amendment with respect to the input signal before correction | amendment of Example 2 which concerns on this invention. It is a figure of the example of the representative value showing the relationship of the output signal after correction | amendment with respect to the input signal before correction | amendment of Example 3 which concerns on this invention.

  A correction signal corresponding to a desired color signal value and a color signal value other than the desired color signal when correcting a desired color signal among the R, G, and B signals that are the three primary color signals of the image signal This is achieved by controlling the magnitude of the correction signal using the control signal generated from the color signal values other than the two colors and the desired reference signal value, correcting the input image signal, and outputting the signal. did.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments.
First, the image signal correcting means 10 will be described as an example with reference to FIG.
The image signal correction means 10
An input terminal 20 to which an R signal that is a red component of an image signal is input;
An input terminal 21 to which a G signal which is a green component of the image signal is input;
An input terminal 22 to which a B signal which is a blue component of the image signal is input;
B reference signal generating means 32 for generating a desired reference signal;
G reference signal generation means 31 for generating a desired reference signal;
B control signal generating means 42 connected to the input terminal 22, the B reference signal generating means 32, and the G correction signal generating means 51 in the subsequent stage;
A G control signal generating means 41 connected to the input terminal 21, the G reference signal generating means 31, and the B correction signal generating means 52 in the subsequent stage;
G correction signal generation means 51 connected to the input terminal 20, the input terminal 21, the B control signal generation means 42, and the G correction means 61 in the subsequent stage;
A B correction signal generation unit 52 connected to the input terminal 20, the input terminal 22, the G control signal generation unit 41, and the B correction unit 62 in the subsequent stage;
G correction means 61 connected to the input terminal 21, the G correction signal generation means 51, and the output terminal 71 in the subsequent stage;
B correction means 62 connected to the input terminal 22, the B correction signal generation means 52, and the output terminal 72 in the subsequent stage;
An output terminal 70 connected to the input terminal 20;
An output terminal 71 connected to the G correction means 61;
And an output terminal 72 connected to the B correction means 62.
Note that the B reference signal necessary for the B control signal generating means 42 can be set in advance in the B control signal generating means 42. In that case, the B reference signal generating means 32 is unnecessary. Similarly, a value of the G reference signal necessary for the G control signal generation unit 41 can be set in the G control signal generation unit 41 in advance. In that case, the G reference signal generating means 31 is unnecessary.
In addition, each reference signal value is effectively corrected in a region that is difficult to see for those suffering from the first color blindness, and is not corrected in a region where the G signal and the B signal are equal to or greater than the desired reference signal value. For this reason, in order to achieve a balance between reducing the sense of discomfort for a healthy person, for example, a predetermined value smaller than half of the maximum value, preferably about 25% to 49% of the maximum value, and more preferably 40 of the maximum value. It may be set to about% (signal value 102). However, various changes can be made to the extent that the effect is not hindered. If it is desired to expand the correction range, it may be more than 50%. However, considering compatibility with healthy people, it is not very desirable to make it nearly 100%. Further, in the case of a color blind person who is relatively close to a healthy person, the reference value may be reduced to narrow the correction area.
In this embodiment, the B reference signal generating unit 32 and the G reference signal generating unit 31 generate 102 (40%) reference signals.

The image signal correcting means 10 configured as described above has a larger correction amount of G correction signal or B correction signal as the R signal value, which is dark red, increases, or as the G signal value or B signal value decreases. Added. Conversely, the smaller the R signal value, or the larger the G signal value or B signal value, the smaller the correction amount, and a correction signal is generated when the G signal or B signal is greater than or equal to the desired reference signal value. Not.
When the R signal = 255, G signal = 0, and B signal = 0, which are dark red, are input to the image signal correcting means 10, the R signal = 255, the G signal = 51, and the B signal = 51 are corrected. The case will be described with reference to FIG.

The R signal = 255, the G signal = 0, and the B signal = 0 are input to the input terminals 20, 21, 22 of the image signal correction means 10, respectively.
The input terminal 20 receives an R signal that is a red component of the image signal,
A G signal which is a green component of the image signal is input to the input terminal 21,
A B signal that is a blue component of the image signal is input to the input terminal 22.
Therefore, the R signal is input to the G correction signal generation unit 51 and the B correction signal generation unit 52 and is output from the output terminal 70,
The G signal is input to the G control signal generation means 41, the G correction signal generation means 51, and the G correction means 61,
The B signal is input to the B control signal generation unit 42, the B correction signal generation unit 52, and the B correction unit 62.

Based on the input B signal and B reference signal, the B control signal generation means 42 does not generate a B control signal when the B signal value is larger than the B reference signal value, and the B signal value is the B reference signal value. When the difference value is smaller, it is linked to the difference value obtained by subtracting the B signal value from the B reference signal value. That is, if the difference value is small, the B control signal is small, and if the difference value is large, the B control signal is large. The B control signal is generated by calculating the tendency, and output to the G correction signal generation means 51 in the subsequent stage. Therefore, the B control signal has a feature that is inversely proportional to the B signal value and proportional to the difference value between the B signal value and the B reference signal value, and controls the magnitude of the correction amount of the G correction signal generation means 51 in the subsequent stage.
As an example of the calculation for generating the control signal by the B control signal generating means 42,
The input B signal is B, where B is 0 to 255,
When the B reference signal generated by the B reference signal generating means 32 is BS, where BS is 0 to 255 (BS-B) is a negative value, the generated B control signal is 0,
When (BS−B) is a positive value, B control signal = (BS−B) ÷ BS,
A control signal is generated. Therefore, the B control signal is 0 to 1.
In the present embodiment, the B control signal is determined to be in the range of 0 to 1 by the above formula, but various modifications are possible. The B control signal is a signal proportional to the correction amount for determining the correction amount. If 0, the correction amount = 0, and the larger the value, the larger the B correction signal value. The correction amount is maximized.

この表１に示す様に制御信号は、入力信号が基準信号未満になったときに補正信号の大小を制御するための制御信号が生成され、入力信号が基準値未満で且つ小さな値ほど大きな制御信号が生成され、入力信号が基準値未満で且つ大きな値ほど小さな制御信号が生成される。 Table 1 below shows typical values of the B control signal generated based on the B signal and the B reference signal in this example.

As shown in Table 1, when the input signal becomes less than the reference signal, a control signal for controlling the magnitude of the correction signal is generated, and the control signal is larger as the input signal is less than the reference value and smaller. A signal is generated, and a smaller control signal is generated as the input signal is smaller than the reference value and larger.

In the case where the B control signal generating means 42 adopts a system that uses an input / output comparison table to correct digitized gradation data, which is a lookup table system, to an arbitrary gradation, the If the B signal value is larger than the B reference signal value based on the information of the comparison table based on the input B signal and a predetermined B reference signal, the B control signal is not generated, and the B signal value is the B reference signal. When the difference value is smaller than the value, the smaller the difference value obtained by subtracting the B signal value from the B reference signal value, the smaller the generated B control signal, and the larger the difference value, the larger the generated B control signal. It is possible to obtain the same information as the desired calculation result.
Therefore, when the B control signal generation means 42 is a lookup table system or a system equivalent thereto, the B reference signal generation means 32 may be omitted or may be incorporated in the lookup table means. A similar B control signal is obtained.

The G correction signal generation means 51 is uniquely determined according to the R signal value, the G signal value, and the B control signal value, that is, the correction signal is related to the magnitude of the R signal value and the G signal value. A correction signal for determining the magnitude of the correction value is generated, the magnitude of the correction signal is controlled by the B control signal, and output to the G correction means 61. The G correction signal generating means 51 generates a G correction signal that tends to be proportional to the R signal value, inversely proportional to the G signal value, and proportional to the B control signal.
As an example of the calculation in which the G correction signal generation means 51 generates a correction signal,
GK1 is a desired coefficient, for example 2.5,
GK2 is a desired coefficient, for example 5,
The input R signal is R, where R is 0 to 255,
When the input G signal is G, where G is 0 to 255,
When (R− (G × GK1)) is a negative value, the generated G correction signal is 0,
When (R− (G × GK1)) is a positive value,
G correction signal = ((R− (G × GK1)) ÷ GK2) × B control signal,
A G correction signal is generated.
GK1 and GK2 are coefficients that are desired when generating the correction signal and can be changed. When the value is decreased, the generated correction signal is increased. When the value is increased, the generated correction signal is decreased. . By appropriately setting this coefficient, it is possible to adjust the correction amount and the correction range, and the correction is effectively performed in a hard-to-see area where it is difficult for a person with color blindness to distinguish, and in a region where the B signal is equal to or higher than a desired reference signal value It is possible to appropriately set a range in which it is possible to achieve both the uncorrected and uncomfortable feeling for the healthy person.

The G correction signal generating means 51 does not generate a G correction signal based on the input R signal and G signal, and does not generate a G correction signal when the R signal value is smaller than a value obtained by multiplying the G signal value by a desired coefficient GK1. If the value is larger than the value obtained by multiplying the G signal value by a desired coefficient GK, a G correction signal is generated.
The G correction signal is generated as the R signal value is larger or the G signal value is smaller. Conversely, the G correction signal is generated as the R signal value is smaller or the G signal value is larger. An operation in which the signal value is small, that is, proportional to the R signal value, inversely proportional to the G signal value, and further, the correction signal value and the correction range are adjusted from the relationship between the R signal value and the G signal value by the coefficient GK1. The magnitude is adjusted by dividing the result by the desired coefficient GK2, and the magnitude of the value is further controlled by the B control signal, that is, G is inversely proportional to the desired coefficient GK2 and proportional to the B control signal. A correction signal is generated and output to the G correction means 61.
Therefore, the G correction signal is proportional to the R signal value, is inversely proportional to the G signal value, and the correction signal value and the correction range are appropriately set based on the relationship between the R signal value and the G signal value by the coefficient GK1, It has a tendency to be inversely proportional to the desired coefficient GK2 and proportional to the B control signal. In other words, a correction range is appropriately set based on the relationship between the coefficient, the R signal, and the G signal, and is proportional to the R signal value. It is inversely proportional, proportional to the B control signal, and has a tendency to adjust the value by a coefficient.

この表２に示す様にＧ補正信号は、Ｂ信号値がＢ基準信号値未満であるときに、Ｒ信号値に比例し、且つ、Ｇ信号値に逆比例したＧ補正信号が生成される。 Table 2 shows representative values of the G correction signal generated based on the R signal, the G signal, and the B control signal in this example.

As shown in Table 2, when the B signal value is less than the B reference signal value, the G correction signal is generated in proportion to the R signal value and inversely proportional to the G signal value.

In the case where the G correction signal generating means 51 adopts a method that uses an input / output comparison table to correct digitized gradation data, which is a look-up table method, to an arbitrary gradation. If the R signal value is smaller than the value obtained by multiplying the G signal value by a desired coefficient GK1 based on the R and G signals inputted, the correction signal is not generated and the R signal value is G. When the signal value is larger than the desired value GK1 times, the smaller the G signal value or the larger the R signal value, the larger the correction signal value generated, and conversely, the larger the G signal value or the R signal. The desired calculation is characterized in that the smaller the value is, the smaller the correction signal value is generated. The calculation result is divided by the desired coefficient GK2 for setting the magnitude of the correction signal value, and the calculation result is further calculated. B And the desired result of operation, characterized in that at control signal is controlled magnitude value, may be a similar information.
Therefore, even if the G correction signal generating means 51 is a lookup table method or a method equivalent thereto, it tends to be proportional to the R signal value and inversely proportional to the G signal value. A G correction signal whose magnitude is controlled can be generated.

The G control signal generation means 41 does not generate a G control signal when the G signal value is larger than the G reference signal value based on the input G signal and the G reference signal, and the G signal value is the G reference signal value. When the difference value is smaller, it is linked to the magnitude of the difference value obtained by subtracting the G signal value from the G reference signal value, that is, the G control signal is small when the difference value is small, and the G control signal is large when the difference value is large. The G control signal is generated by calculating the tendency, and output to the B correction signal generation unit 52 at the subsequent stage. Accordingly, the G control signal has a feature that is inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value, and controls the magnitude of the correction amount of the B correction signal generation means 52 in the subsequent stage.
As an example of the calculation that the G control signal generating means 41 generates the control signal,
The input G signal is G, where G is 0 to 255,
When the G reference signal generated by the G reference signal generating means 31 is GS, where GS is 0 to 255,
When (GS−G) is a negative value, the generated G control signal is 0,
When (GS−G) is a positive value, G control signal = (GS−G) ÷ GS,
A G control signal is generated. Therefore, the G control signal is 0 to 1.
In the present embodiment, the G control signal is determined to be in the range of 0 to 1 by the above formula, but various modifications are possible. The G control signal is a signal proportional to the correction amount for determining the correction amount. If 0, the correction amount = 0, and the larger the numerical value, the larger the G correction signal value. The correction amount is maximized.

  The representative values of the G control signal generated based on the G signal and the G reference signal in this example are the same as those in Table 1.

  If the G control signal generation means 41 is a lookup table system or a system equivalent thereto, the G reference signal generation means 31 may be omitted or may be built in the lookup table means, as described above. A G control signal can be obtained.

The B correction signal generation means 52 is uniquely determined according to the R signal value, the B signal value, and the G control signal value, that is, the correction signal is related to the magnitude of the R signal value and the B signal value. A correction signal for determining the magnitude of the value is generated, and the magnitude of the correction signal is controlled by the G control signal and output to the B correction means 62. The B correction signal generation means 52 generates a B correction signal that tends to be proportional to the R signal value, inversely proportional to the B signal value, and proportional to the G control signal.
As an example of the calculation in which the B correction signal generation unit 52 generates a correction signal,
BK1 is a desired coefficient, for example 2.5,
BK2 is a desired coefficient, for example 5,
The input R signal is R, where R is 0 to 255,
When the input B signal is B, where B is 0 to 255,
When (R− (B × BK1)) is a negative value, the generated B correction signal is 0,
When (R− (B × BK1)) is a positive value,
B correction signal = ((R− (B × BK1)) ÷ BK2) × G control signal,
A B correction signal is generated.
Note that BK1 and BK2 are desired coefficients for generating the correction signal and can be changed. When the value is decreased, the generated correction signal is increased, and when the value is increased, the generated correction signal is decreased. . By appropriately setting this coefficient, it is possible to adjust the correction amount and the correction range, and it is effectively corrected in a region where it is difficult to distinguish a person with color blindness, and the G signal is equal to or greater than a desired reference signal value. It is possible to appropriately set a range in which it is possible to achieve both the uncorrected and uncomfortable feeling for a healthy person.

The B correction signal generation means 52 does not generate a correction signal based on the input R signal and B signal, and generates an R signal value when the R signal value is smaller than a value obtained by multiplying the B signal value by a desired coefficient BK1. Is larger than the value obtained by multiplying the B signal value by a desired coefficient BK1, a B correction signal is generated,
The B correction signal is generated as the R signal value increases or the B signal value decreases. Conversely, the B correction signal is generated as the R signal value decreases or the B signal value increases. An operation in which the signal value is small, that is, proportional to the R signal value, inversely proportional to the B signal value, and further, the correction signal value and the correction range are adjusted from the relationship between the R signal value and the B signal value by the coefficient BK1. The magnitude is adjusted by dividing the result by the desired coefficient BK2, and the magnitude of the value is further controlled by the G control signal, that is, B is inversely proportional to the desired coefficient BK2 and proportional to the G control signal. A correction signal is generated and output to the B correction means 62.
Therefore, the B correction signal is proportional to the R signal value, is inversely proportional to the B signal value, and the correction signal value and the correction range are appropriately adjusted from the relationship between the R signal value and the B signal value by the coefficient BK1, It has a tendency to be inversely proportional to the desired coefficient BK2 and proportional to the G control signal, that is, the correction range is appropriately set from the relationship between the coefficient, the R signal value, and the B signal value, and is proportional to the R signal value. Inversely proportional to the value, proportional to the G control signal, and has a tendency to be adjusted by a coefficient.

  The representative values of the B correction signal generated based on the R signal, the B signal, and the G control signal in this example are the same as those in Table 2.

  Even if the B correction signal generating means 52 is a lookup table method or a method equivalent thereto, it tends to be proportional to the R signal value and inversely proportional to the B signal value. A G correction signal whose size is controlled can be generated.

この表３では上述したように、Ｂ信号値が基準信号値未満であるときに、Ｒ信号値に比例し、且つ、Ｇ信号値に逆比例したＧ補正信号を生成し、そのＧ補正信号をＧ信号に付加する補正を行った補正後の値を示す。同様に、Ｇ信号値が基準信号値未満であるときに、Ｒ信号値に比例し、且つ、Ｂ信号値に逆比例したＢ補正信号を生成し、そのＢ補正信号をＢ信号に付加する補正を行った補正後の値を示す。又、補正のない部分では、元の信号がそのまま出力されている。 The G correction unit 61 performs correction by adding the G signal from the input terminal 21 based on the G correction signal from the G correction signal generation unit 51, and outputs the corrected signal to the output terminal 71.
The B correction unit 62 performs correction by adding the B signal from the input terminal 22 based on the B correction signal from the B correction signal generation unit 52, and outputs the corrected signal to the output terminal 72.
The representative values of the G signal corrected by the G correction signal of this example and the representative values of the B signal corrected by the B correction signal are shown in the following Table 3 and FIG.

As described above in Table 3, when the B signal value is less than the reference signal value, a G correction signal that is proportional to the R signal value and inversely proportional to the G signal value is generated. A corrected value obtained by performing correction added to the G signal is shown. Similarly, when the G signal value is less than the reference signal value, a B correction signal proportional to the R signal value and inversely proportional to the B signal value is generated, and the B correction signal is added to the B signal. It shows the value after correction performed. In addition, the original signal is output as it is in a portion without correction.

As a result, in this embodiment for correcting dark red, when the G signal is corrected, a correction signal related to the magnitude of the values of the R signal and the G signal is generated, and when the B signal is 0, the correction is performed. Since the control signal for controlling the amount is 1, that is, the B signal is dark red because it is dark red, the G signal is corrected. As the B signal approaches the reference signal value from 0, the correction amount decreases. If the signal value is greater than or equal to the signal value, the control signal for controlling the correction amount is 0, that is, no correction is performed because the B signal is greater than the reference signal value and not dark red.
In the case of correcting the B signal, a correction signal related to the magnitude of the values of the R signal and the B signal is generated, and when the G signal is 0, the control signal for controlling the correction amount is 1, that is, the G signal. Since there is no dark red, the B signal is corrected, and the correction amount decreases each time the G signal approaches the reference signal value from 0. Is 0, that is, the G signal is equal to or greater than the reference signal value, and is not dark red, so correction is not performed.

Therefore, when correcting the dark red, since the generated correction signal and control signal value are large, large correction is performed. When R signal = 255, G signal = 0, and B signal = 0 are input, 51 is generated as a correction signal value, and is corrected to R signal = 255, G signal = 51, and B signal = 51.
In addition, in the case of red but having other color components, such as R signal = 255, G signal = 102, B signal = 0, R signal = 255, G signal = 0, and B signal = 102, the correction signal Alternatively, no correction is performed because no control signal is generated.
Further, when R signal = 230, G signal = 0, and B signal = 0 are input, 46 is generated as respective correction signal values, and corrected to R signal = 230, G signal = 46, and B signal = 46,
When R signal = 204, G signal = 0, and B signal = 0 are input, 41 is generated as each correction signal value, and corrected to R signal = 204, G signal = 41, and B signal = 41,
When R signal = 255, G signal = 26, and B signal = 26 are input, 28 are generated as respective correction signal values, and corrected to R signal = 255, G signal = 54, B signal = 54,
When R signal = 255, G signal = 51, and B signal = 51 are input, 13 are generated as respective correction signal values, and can be corrected to R signal = 255, G signal = 64, and B signal = 64. .

Further, in the G correction signal generation means 51 of the present embodiment, the correction range is set according to the calculation result of (R− (G × GK1)), but the G reference set in advance for other G signals. Even if the correction signal is generated when the signal value, for example, the G signal value is less than 102 (40%), the same effect can be obtained.
Furthermore, the correction amount is determined by the calculation result of (R− (G × GK1)) ÷ GK2) × B control signal, but is proportional to the other R signal values and inversely proportional to the G signal value, and the B control. The same effect can be obtained by means of adjusting the magnitude by calculating with some coefficients in proportion to the signal (inversely proportional to the B signal value and proportional to the difference value between the B signal value and the B reference signal value). Is obtained.
Accordingly, a new G reference signal value for the G signal is preset in the G correction signal generating means 51, and is proportional to the R signal value and inversely proportional to the G signal value. Proportional to the difference value, proportional to the B control signal (inversely proportional to the B signal value and proportional to the difference value between the B signal value and the B reference signal value), and the size is adjusted by calculating with several coefficients. Similar effects can be obtained as a means.
For example, the G reference signal value is GS,
When a signal that is inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value is used as the G control signal,
G control signal = ((GS−G) ÷ GS), where the G control signal is 0 to 1,
B reference signal value is BS,
B control signal = ((BS−B) ÷ BS), where the B control signal is an example of 0 to 1,
G correction signal = ((R ÷ coefficient) × G control signal) × B control signal, that is,
G correction signal = ((R ÷ GK2) × ((GS−G) ÷ GS)) × ((BS−B) ÷ BS),
The same effect can be obtained.

Further, in the B correction signal generation means 52 of this embodiment, the correction range is set by the calculation result of (R− (B × BK1)), but the B reference set in advance for other B signals in advance. Even if the correction signal is generated when the signal value, for example, the B signal value is less than 102 (40%), the same effect can be obtained.
Furthermore, the correction amount is determined by the calculation result of (R− (B × BK1)) ÷ BK2) × G control signal, but is proportional to the other R signal values and inversely proportional to the B signal values, and the G control. The same effect can be obtained by means of calculating with some coefficients and adjusting the magnitude in proportion to the signal (inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value). Is obtained.
Therefore, a new B reference signal value for the B signal is preset in the B correction signal generating means 52, and is proportional to the R signal value and inversely proportional to the B signal value. Proportional to the difference value, proportional to the G control signal (inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value), and the size is adjusted by calculating with several coefficients. The same effect can be obtained as a means.
For example, B reference signal value is BS,
When a signal that is inversely proportional to the B signal value and proportional to the difference value between the B signal value and the B reference signal value is used as the B control signal
B control signal = ((BS−B) ÷ BS), where B control signal is 0 to 1,
G reference signal value is GS,
G control signal = ((GS−G) ÷ GS), where the G control signal is an example of 0 to 1,
B correction signal = ((R ÷ coefficient) × B control signal) × G control signal, that is,
B correction signal = ((R ÷ BK2) × ((BS−B) ÷ BS)) × (GS−G) ÷ GS),
The same effect can be obtained.
Further, for example, BS is a preset reference signal value 102,
GS is a preset reference signal value 102,
BK2 is a desired coefficient, and when it is set to 5 as an example, the value of the generated G correction signal or B correction signal is
When R signal = 255, G signal = 0, and B signal = 0, 51 is generated as a correction signal value,
When R signal = 230, G signal = 0, and B signal = 0, 46 is generated as a correction signal value,
When R signal = 204, G signal = 0, and B signal = 0, 41 is generated as a correction signal value,
When R signal = 255, G signal = 26, and B signal = 26 are input, 28 is generated as a correction signal value,
When R signal = 255, G signal = 51, and B signal = 51 are input, 13 is generated as a correction signal value.
When R signal = 255, G signal = 102, B signal = 0, R signal = 255, G signal = 0, and B signal = 102, no correction signal is generated, and the same effect can be obtained.

As described above, when the G signal is corrected, the B control signal generated based on the B signal value and the B reference signal value, the correction signal generated based on the R signal value and the G signal value, Thus, the correction can be performed by changing the correction amount.
This corrects only dark red, generates a G correction signal that tends to be proportional to the R signal value and inversely proportional to the G signal value or the B signal value. A correction added to the signal is performed to change the appearance of red. That is, the larger the R signal value that is dark red, or the smaller the B signal value or G signal value, the larger the G correction signal is added. Conversely, the smaller the R signal value, or the larger the B signal value or G signal value, the smaller the correction amount. Further, if the B signal is greater than the desired reference signal value, no correction signal is generated.
When correcting the B signal, the correction amount is set according to the G control signal generated based on the G signal value and the G reference signal value, and the correction signal generated based on the R signal value and the B signal value. It can be corrected by changing.
As a result, only the dark red is corrected, and a B correction signal that tends to be proportional to the R signal value and is inversely proportional to the G signal value or the B signal value is generated. A correction added to the signal is performed to change the appearance of red. That is, as the R signal value, which is dark red, increases, or as the G signal value or B signal value decreases, a B correction signal with a larger correction amount is added. Conversely, the smaller the R signal value, or the larger the G signal value or B signal value, the smaller the correction amount. Further, if the G signal is greater than the desired reference signal value, no correction signal is generated.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate, and the G signal or B signal is not corrected in the area that is greater than the desired reference signal value, the healthy person also feels uncomfortable. An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

Next, with reference to FIG. 2, a description will be given of a case where the image signal correcting unit 10A is used as an example.
The image signal correcting means 10A
An input terminal 20 to which an R signal that is a red component of an image signal is input;
An input terminal 21 to which a G signal which is a green component of the image signal is input;
An input terminal 22 to which a B signal which is a blue component of the image signal is input;
R reference signal generating means 30 for generating a desired reference signal;
An R control signal generating means 40 connected to the input terminal 20, the R reference signal generating means 30, and the B correction signal generating means 52 in the subsequent stage;
B correction signal generation means 52 connected to the input terminal 21, the input terminal 22, the R control signal generation means 40, and the B correction means 62 in the subsequent stage;
B correction means 62 connected to the input terminal 22, the B correction signal generation means 52, and the output terminal 72 in the subsequent stage;
An output terminal 70 connected to the input terminal 20;
An output terminal 71 connected to the input terminal 21;
And an output terminal 72 connected to the B correction means 62.
Note that the R reference signal necessary for the R control signal generation means 40 can be set in advance in the R control signal generation means 40. In that case, the R reference signal generating means 30 is unnecessary.
In addition, the reference signal value is effectively corrected in a region where it is difficult to identify a person suffering from the first color blindness, and the correction is not performed in a region where the R signal is greater than the desired reference signal value. In order to make the sense of incongruity small, for example, a predetermined value smaller than half of the maximum value, preferably about 25% to 49% of the maximum value, more preferably 40% of the maximum value (signal value 102). ) It should be set to a degree. However, various changes can be made to the extent that the effect is not hindered. If it is desired to expand the correction range, it may be more than 50%. However, considering compatibility with healthy people, it is not very desirable to make it nearly 100%. Further, in the case of a color blind person who is relatively close to a healthy person, the reference value may be reduced to narrow the correction area.
In this embodiment, the R reference signal generation unit 30 generates 102 (40%) reference signals.

The image signal correction means 10A configured as described above adds a B correction signal with a larger correction amount as the G signal value, which is dark green, increases or as the R signal value or B signal value decreases. . Conversely, the smaller the G signal value, or the larger the R signal value or B signal value, the smaller the correction amount, and further, no correction signal is generated if the R signal is greater than or equal to the desired reference signal value.
When R signal = 0, G signal = 255, and B signal = 0, which are dark green, are input to the image signal correcting unit 10A, the signal is corrected to R signal = 0, G signal = 255, and B signal = 51. The case will be described with reference to FIG.

R signal = 0, G signal = 255, and B signal = 0 are input to the input terminals 20, 21, and 22 of the image signal correcting means 10A, respectively.
The input terminal 20 receives an R signal that is a red component of the image signal,
A G signal which is a green component of the image signal is input to the input terminal 21,
A B signal that is a blue component of the image signal is input to the input terminal 22.
Therefore, the R signal is input to the R control signal generating means 40 and output at the output terminal 70, and
The G signal is input to the B correction signal generating means 52 and output at the output terminal 71,
The B signal is input to the B correction signal generation unit 52 and the B correction unit 62.

The R control signal generation unit 40 does not generate an R control signal when the R signal value is larger than the R reference signal value based on the input R signal and the R reference signal, and the R signal value is the R reference signal value. When the difference value is smaller, it is linked to the difference value obtained by subtracting the R signal value from the R reference signal value. That is, if the difference value is small, the B control signal is small, and if the difference value is large, the B control signal is large. An R control signal is generated by calculating the tendency, and output to the B correction signal generation means 52 at the subsequent stage. Therefore, the R control signal has a feature that is inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value, and controls the magnitude of the correction amount of the B correction signal generation means 52 in the subsequent stage.
As an example of the calculation that the R control signal generation means 40 generates the control signal,
The input R signal is R, where R is 0 to 255,
When the R reference signal generated by the R reference signal generating means 30 is RS, where RS is 0 to 255 (RS-R) is a negative value, the generated R control signal is 0,
When (RS−R) is a positive value, R control signal = (RS−R) ÷ RS,
A control signal is generated. Therefore, the R control signal is 0 to 1.
In the present embodiment, the R control signal is determined to be in the range of 0 to 1 by the above formula, but various modifications are possible. The R control signal is a signal proportional to the correction amount for determining the correction amount. If 0, the correction amount = 0, and the larger the numerical value, the larger the R correction signal value. The correction amount is maximized.

この表４に示す様に制御信号は、入力信号が基準信号未満になったときに補正信号の大小を制御するための制御信号が生成され、入力信号が基準値未満で且つ小さな値ほど大きな制御信号が生成され、入力信号が基準値未満で且つ大きな値ほど小さな制御信号が生成される。 Table 4 below shows typical values of the R control signal generated based on the R signal and the R reference signal in this example.

As shown in Table 4, when the input signal becomes less than the reference signal, a control signal for controlling the magnitude of the correction signal is generated. When the input signal is less than the reference value and the value is smaller, the control signal is larger. A signal is generated, and a smaller control signal is generated as the input signal is smaller than the reference value and larger.

  When the R control signal generation means 40 is a lookup table method or a method equivalent thereto, the R reference signal generation means 30 may be omitted or may be built in the lookup table means. A similar R control signal is obtained.

The B correction signal generation means 52 is uniquely determined according to the G signal value, the B signal value, and the R control signal value, that is, the correction signal is related to the magnitude of the G signal value and the B signal value. A correction signal for determining the magnitude of the value is generated, and the magnitude of the correction signal is controlled by the R control signal and output to the B correction means 62. The B correction signal generation means 52 generates a B correction signal that tends to be proportional to the G signal value, inversely proportional to the B signal value, and proportional to the R control signal.
As an example of the calculation in which the B correction signal generation unit 52 generates a correction signal,
BK1 is a desired coefficient, for example 2.5,
BK2 is a desired coefficient, for example 5,
The input G signal is G, where G is 0 to 255,
When the input B signal is B, where B is 0 to 255,
When (G− (B × BK1)) is a negative value, the generated B correction signal is 0,
When (G− (B × BK1)) is a positive value,
B correction signal = ((G− (B × BK1)) ÷ BK2) × R control signal,
A correction signal B is generated.
Note that BK1 and BK2 are desired coefficients for generating the correction signal and can be changed. When the value is decreased, the generated correction signal is increased, and when the value is increased, the generated correction signal is decreased. . By appropriately setting this coefficient, it is possible to adjust the correction amount and the correction range, and it is effectively corrected in a hard-to-see area where it is difficult for a person with color blindness to be distinguished. It is possible to appropriately set a range in which it is possible to achieve both the uncorrected and uncomfortable feeling for the healthy person.

The B correction signal generation means 52 does not generate a correction signal based on the input G signal and B signal, and generates a G signal value when the G signal value is smaller than a value obtained by multiplying the B signal value by a desired coefficient BK1. Is larger than the value obtained by multiplying the B signal value by a desired coefficient BK1, a B correction signal is generated,
The B correction signal is generated as the G signal value increases or the B signal value decreases. Conversely, the B correction signal is generated as the G signal value decreases or the B signal value increases. An operation in which the signal value becomes smaller, that is, proportional to the G signal value, inversely proportional to the B signal value, and further, the correction signal value and the correction range are adjusted by the coefficient BK1 from the relationship between the G signal value and the B signal value. The magnitude is adjusted by dividing the result by the desired coefficient BK2, and the magnitude of the value is further controlled by the R control signal, that is, B is inversely proportional to the desired coefficient BK2 and proportional to the R control signal. A correction signal is generated and output to the B correction means 62.
Therefore, the B correction signal is proportional to the G signal value, is inversely proportional to the B signal value, and the correction signal value and the correction range are appropriately set based on the relationship between the G signal value and the B signal value by the coefficient BK1, It has a tendency to be inversely proportional to the desired coefficient BK2 and proportional to the R control signal. In other words, a correction range is appropriately set based on the relationship between the coefficient, the G signal, and the B signal, and is proportional to the G signal value. It is inversely proportional, proportional to the R control signal, and has a tendency to adjust the value by a coefficient.

この表５に示す様にＢ補正信号は、Ｒ信号値がＲ基準信号値未満であるときに、Ｇ信号値に比例し、且つ、Ｂ信号値に逆比例したＢ補正信号が生成される。 Table 5 below shows representative values of the B correction signal generated based on the G signal, the B signal, and the R control signal in this example.

As shown in Table 5, when the R signal value is less than the R reference signal value, the B correction signal is generated in proportion to the G signal value and inversely proportional to the B signal value.

  Even if the B correction signal generating means 52 is a lookup table method or a method equivalent thereto, it tends to be proportional to the G signal value and inversely proportional to the B signal value. A B correction signal whose size is controlled can be generated.

この表６では上述したように、Ｒ信号値が基準信号値未満であるときに、Ｇ信号値に比例し、且つ、Ｂ信号値に逆比例した状態のＢ補正信号を生成し、そのＢ補正信号をＢ信号に付加する補正を行った、補正後の値を示す。又、補正のない部分では、元の信号がそのまま出力されている。 The B correction unit 62 performs correction by adding the B signal from the input terminal 22 based on the B correction signal from the B correction signal generation unit 52, and outputs the corrected signal to the output terminal 72.
Representative values of the B signal corrected by the B correction signal of this example are shown in the following Table 6 and FIG.

As described above in Table 6, when the R signal value is less than the reference signal value, a B correction signal in a state proportional to the G signal value and inversely proportional to the B signal value is generated. A corrected value obtained by adding a signal to the B signal is shown. In addition, the original signal is output as it is in a portion without correction.

  As a result, in this embodiment for correcting dark green, when correcting the B signal, a correction signal related to the magnitude of the values of the G signal and the B signal is generated, and when the R signal is 0, the correction is performed. The control signal for controlling the amount is 1, that is, there is no R signal and dark green, so the B signal is corrected. As the R signal approaches the reference signal value from 0, the correction amount decreases. When the signal value is equal to or greater than the signal value, the control signal for controlling the correction amount is 0, that is, the R signal is equal to or greater than the reference signal value and is not dark green, and thus correction is not performed.

Therefore, when correcting dark green, the correction signal and control signal value to be generated are large, so that a large correction is performed. When R signal = 0, G signal = 255, and B signal = 0 are input, the correction signal A value of 51 is generated and corrected to R signal = 0, G signal = 255, and B signal = 51.
In addition, when R signal = 102, G signal = 255, B signal = 0, R signal = 0, G signal = 255, and B signal = 102, although there are other color components, the correction signal Alternatively, no correction is performed because no control signal is generated.
Further, when R signal = 0, G signal = 230, and B signal = 0, 46 is generated as a correction signal value, and corrected to R signal = 0, G signal = 230, B signal = 46,
When R signal = 0, G signal = 204, and B signal = 0 are input, 41 is generated as each correction signal value, and corrected to R signal = 0, G signal = 204, B signal = 41,
When R signal = 0, G signal = 255, and B signal = 26 are input, 28 are generated as respective correction signal values, and corrected to R signal = 0, G signal = 255, and B signal = 54,
When R signal = 0, G signal = 255, and B signal = 51 are input, 13 are generated as respective correction signal values, and can be corrected to R signal = 0, G signal = 255, and B signal = 64. .

Further, in the B correction signal generation means 52 of the present embodiment, the correction range is set by the calculation result of (G− (B × BK1)), but the B reference set in advance for other B signals in advance. Even if the correction signal is generated when the signal value, for example, the B signal value is less than 102 (40%), the same effect is obtained.
Further, the correction amount is determined by the calculation result of (G− (B × BK1)) ÷ BK2) × R control signal, but is proportional to the other G signal value and inversely proportional to the B signal value, and the R control. The same effect can be obtained by means of adjusting the magnitude by calculating with some coefficients in proportion to the signal (inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value). Is obtained.
Therefore, a new B reference signal value for the B signal is preset in the B correction signal generating means 52, and is proportional to the G signal value and inversely proportional to the B signal value. Proportional to the difference value, proportional to the R control signal (inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value), and the size is adjusted by calculation using several coefficients. Similar effects can be obtained as a means.
For example, B reference signal value is BS,
When a signal that is inversely proportional to the B signal value and proportional to the difference value between the B signal value and the B reference signal value is used as the B control signal
B control signal = ((BS−B) ÷ BS), where B control signal is 0 to 1,
R reference signal value is RS,
R control signal = ((RS−R) ÷ RS), where R control signal is an example of 0 to 1,
B correction signal = ((G ÷ coefficient) × B control signal) × R control signal, that is,
B correction signal = ((G ÷ BK2) × ((BS−B) ÷ BS)) × (RS−R) ÷ RS),
The same effect can be obtained.
Further, for example, RS is a preset reference signal value 102,
BS is a reference signal value set in advance 102,
BK2 is a desired coefficient, and when it is set to 5 as an example, the value of the generated B correction signal is
When G signal = 255, B signal = 0, and R signal = 0, 51 is generated as a correction signal value,
When G signal = 230, B signal = 0, and R signal = 0, 46 is generated as a correction signal value,
When G signal = 204, B signal = 0, and R signal = 0 are input, 41 is generated as a correction signal value,
When G signal = 255, B signal = 26, and R signal = 26 are input, 28 is generated as a correction signal value,
When G signal = 255, B signal = 51, and R signal = 51 are input, 13 is generated as a correction signal value,
When the G signal = 255, the B signal = 102, the R signal = 0, the R signal = 255, the G signal = 0, and the B signal = 102, no correction signal is generated, and the same effect can be obtained.

As described above, when the B signal is corrected, the R control signal generated based on the R signal value and the R reference signal value, the correction signal generated based on the G signal value and the B signal value, , The correction amount can be changed and corrected.
This corrects only dark green, generates a B correction signal that tends to be proportional to the G signal value and inversely proportional to the R signal value or the B signal value. A correction is added to the signal to change the appearance of green. That is, as the G signal value, which is dark green, increases, or as the R signal value or B signal value decreases, a B correction signal with a larger correction amount is added. Conversely, the smaller the G signal value, or the larger the R signal value or B signal value, the smaller the correction amount. Further, if the R signal is greater than the desired reference signal value, no correction signal is generated.
For this reason, since a person suffering from the first color blindness is effectively corrected in a hard-to-see area that is difficult to discriminate and is not corrected in an area where the R signal is equal to or higher than a desired reference signal value, a sense of discomfort is reduced even for a healthy person. An image signal correction method that makes it possible to achieve compatibility with other things is executed.

Next, the image signal correcting unit 10B will be described as an example with reference to FIG.
The image signal correction means 10B
An input terminal 20 to which an R signal that is a red component of an image signal is input;
An input terminal 21 to which a G signal which is a green component of the image signal is input;
An input terminal 22 to which a B signal which is a blue component of the image signal is input;
G reference signal generation means 31 for generating a desired reference signal;
R reference signal generating means 30 for generating a desired reference signal;
G control signal generating means 41 connected to the input terminal 21, the G reference signal generating means 31, and the R correction signal generating means 50 in the subsequent stage;
An R control signal generating means 40 connected to the input terminal 20, the R reference signal generating means 30, and a G correction signal generating means 51 in the subsequent stage;
An R correction signal generating means 50 connected to the input terminal 20, the input terminal 22, the G control signal generating means 41, and the R correcting means 60 in the subsequent stage;
G correction signal generation means 51 connected to the input terminal 21, the input terminal 22, the R control signal generation means 40, and the G correction means 61 in the subsequent stage;
R correction means 60 connected to the input terminal 20, the R correction signal generation means 50, and the output terminal 70 in the subsequent stage;
G correction means 61 connected to the input terminal 21, the G correction signal generation means 51, and the output terminal 71 in the subsequent stage;
An output terminal 70 connected to the R correction means 60;
An output terminal 71 connected to the G correction means 61;
And an output terminal 72 connected to the input terminal 22.
The G reference signal necessary for the G control signal generating means 41 can be set in advance in the G control signal generating means 41. In that case, the G reference signal generating means 31 is unnecessary. Similarly, the R reference signal necessary for the R control signal generation means 40 can be set in advance in the R control signal generation means 40. In that case, the R reference signal generating means 30 is unnecessary.
In addition, each reference signal value is effectively corrected in a region where it is difficult for a person suffering from third color blindness to see, and in a region where the R signal or G signal is equal to or greater than the desired reference signal value, correction is not performed. For this reason, in order to achieve a balance between reducing the sense of incongruity even for a healthy person, for example, a predetermined value smaller than half of the maximum value, preferably about 25% to 49% of the maximum value, and more preferably 40 of the maximum value It may be set to about% (signal value 102). However, various changes can be made to the extent that the effect is not hindered. If it is desired to expand the correction range, it may be more than 50%. However, considering compatibility with healthy people, it is not very desirable to make it nearly 100%. Further, in the case of a color blind person who is relatively close to a healthy person, the reference value may be reduced to narrow the correction area.
In this embodiment, the G reference signal generation unit 31 and the R reference signal generation unit 30 generate 102 (40%) reference signals.

The image signal correction means 10B configured as described above has a larger correction amount of R correction signal or G correction signal as the B signal value, which is dark blue, increases, or as the R signal value or G signal value decreases. Added. Conversely, the smaller the B signal value, or the larger the R signal or G signal, the smaller the correction amount. Further, if the R signal or G signal is greater than the desired reference signal value, no correction signal is generated.

When the R signal = 0, G signal = 0, and B signal = 255, which are dark blue, are input to the image signal correction unit 10B, the correction is made to R signal = 51, G signal = 51, and B signal = 255. The case will be described with reference to FIG.

R signal = 0, G signal = 0, and B signal = 255 are input to the input terminals 20, 21, 22 of the image signal correcting means 10C, respectively.
The input terminal 20 receives an R signal that is a red component of the image signal,
A G signal which is a green component of the image signal is input to the input terminal 21,
A B signal that is a blue component of the image signal is input to the input terminal 22.
Therefore, the R signal is input to the R control signal generation means 40, the R correction signal generation means 50, and the R correction means 60,
The G signal is input to the G control signal generation means 41, the G correction signal generation means 51, and the G correction means 61,
The B signal is input to the R correction signal generation unit 50 and the G correction signal generation unit 51 and is output from the output terminal 72.

The G control signal generator 41 does not generate a G control signal when the G signal value is larger than the G reference signal value based on the input G signal and the G reference signal, and the G signal value is the G reference signal value. When the difference value is smaller, it is linked to the magnitude of the difference value obtained by subtracting the G signal value from the G reference signal value. That is, if the difference value is small, the G control signal is small, and if the difference value is large, the G control signal is large. The G control signal is generated by calculating the tendency, and output to the R correction signal generation means 50 in the subsequent stage. Therefore, the G control signal has a feature that is inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value, and controls the magnitude of the correction amount of the R correction signal generation means 50 in the subsequent stage.
As an example of the calculation that the G control signal generating means 41 generates the control signal,
The input G signal is G, where G is 0 to 255,
When the G reference signal generated by the G reference signal generating means 31 is GS, where GS is 0 to 255,
When (GS−G) is a negative value, the generated G control signal is 0,
When (GS−G) is a positive value, G control signal = (GS−G) ÷ GS,
A control signal is generated. Therefore, the G control signal is 0 to 1.
In the present embodiment, the G control signal is determined to be in the range of 0 to 1 by the above formula, but various modifications are possible. The G control signal is a signal proportional to the correction amount for determining the correction amount. If 0, the correction amount = 0, and the larger the value, the larger the G correction signal value. The correction amount is maximized.

この表７に示す様に制御信号は、入力信号が基準信号未満になったときに補正信号の大小を制御するための制御信号が生成され、入力信号が基準値未満で且つ小さな値ほど大きな制御信号が生成され、入力信号が基準値未満で且つ大きな値ほど小さな制御信号が生成される。 Table 7 below shows representative values of the G control signal generated based on the G signal and the G reference signal in this example.

As shown in Table 7, a control signal for controlling the magnitude of the correction signal is generated when the input signal becomes less than the reference signal, and the control signal is larger as the input signal is less than the reference value and smaller. A signal is generated, and a smaller control signal is generated as the input signal is smaller than the reference value and larger.

  When the G control signal generating means 41 is a lookup table method or a method equivalent thereto, the G reference signal generating means 31 may not be provided or may be incorporated in the lookup table means. A similar G control signal can be obtained.

The R correction signal generation means 50 is uniquely determined according to the B signal value, the R signal value, and the G control signal value, that is, the correction signal is related to the magnitude of the B signal value and the R signal value. A correction signal for determining the magnitude of the value is generated, and the magnitude of the correction signal is controlled by the G control signal and output to the R correction means 60. The R correction signal generation means 50 generates an R correction signal that tends to be proportional to the B signal value, inversely proportional to the R signal value, and proportional to the G control signal value.
As an example of the calculation in which the R correction signal generation means 50 generates a correction signal,
RK1 is a desired coefficient, for example 2.5,
RK2 is a desired coefficient, for example 5,
The input R signal is R, where R is 0 to 255,
When the input B signal is B, where B is 0 to 255,
When (B− (R × RK1)) is a negative value, the generated R correction signal is 0,
When (B- (R × RK1)) is a positive value,
R correction signal = ((B− (R × RK1)) ÷ RK2) × G control signal,
An R correction signal is generated.
Note that RK1 and RK2 are desired coefficients for generating the correction signal and can be changed. When the value is decreased, the generated correction signal is increased. When the value is increased, the generated correction signal is decreased. . By appropriately setting this coefficient, it is possible to adjust the correction amount and the correction range, and it is effectively corrected in a region in which a person with color blindness is difficult to distinguish and difficult to see. It is possible to appropriately set a range in which it is possible to achieve both the uncorrected and uncomfortable feeling for a healthy person.

The R correction signal generation means 50 does not generate an R correction signal when the B signal value is smaller than a value obtained by multiplying the R signal value by a desired coefficient RK1, based on the input B signal and the R signal, and generates the B signal. If the value is larger than the R signal value multiplied by the desired coefficient RK1, an R correction signal is generated,
The R correction signal is generated as the B signal value is larger or the R signal value is smaller. Conversely, the R correction signal is generated as the B signal value is smaller or the R signal value is larger. An operation in which the signal value becomes smaller, that is, proportional to the B signal value, inversely proportional to the R signal value, and further, the correction signal value and the correction range are adjusted by the coefficient RK1 from the relationship between the B signal value and the R signal value. The magnitude is adjusted by dividing the result by the desired coefficient RK2, and the magnitude of the value is further controlled by the G control signal, that is, the R is inversely proportional to the desired coefficient RK2 and proportional to the G control signal. A correction signal is generated and output to the R correction means 60.
Therefore, the R correction signal is proportional to the B signal value, is inversely proportional to the R signal value, and the correction signal value and the correction range are appropriately set based on the relationship between the B signal value and the R signal value by the coefficient RK1, It has a tendency to be inversely proportional to the desired coefficient RK2 and proportional to the G control signal. In other words, a correction range is appropriately set based on the relationship between the coefficient, the B signal, and the R signal, and is proportional to the B signal value. It is inversely proportional, proportional to the G control signal, and has a tendency to adjust the value by a coefficient.

この表８に示す様にＲ補正信号は、Ｇ信号値がＧ基準信号値未満であるときに、Ｂ信号値に比例し、且つ、Ｒ信号値に逆比例したＲ補正信号が生成される。 Table 8 below shows representative values of the R correction signal generated based on the B signal, the R signal, and the G control signal in this example.

As shown in Table 8, when the G signal value is less than the G reference signal value, the R correction signal is generated in proportion to the B signal value and inversely proportional to the R signal value.

  Note that even if the R correction signal generation means 50 is a lookup table method or a method equivalent thereto, it tends to be proportional to the B signal value and inversely proportional to the R signal value. An R correction signal whose size is controlled can be generated.

The R control signal generation unit 40 does not generate an R control signal when the R signal value is larger than the R reference signal value based on the input R signal and the R reference signal, and the R signal value is the R reference signal value. When the difference value is smaller, it is linked to the difference value obtained by subtracting the R signal value from the R reference signal value. That is, if the difference value is small, the R control signal is small, and if the difference value is large, the R control signal is large. The R control signal is generated and output to the G correction signal generation means 51 in the subsequent stage. Therefore, the R control signal has a feature that is inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value, and controls the magnitude of the correction amount of the G correction signal generation means 51 in the subsequent stage.
As an example of the calculation that the R control signal generation means 40 generates the control signal,
The input R signal is R, where R is 0 to 255,
When the R reference signal generated by the R reference signal generating means 30 is RS, where RS is 0 to 255 (RS-R) is a negative value, the generated R control signal is 0,
When (RS−R) is a positive value, R control signal = (RS−R) ÷ RS,
A control signal is generated. Therefore, the R control signal is 0 to 1.
In the present embodiment, the R control signal is determined to be in the range of 0 to 1 by the above formula, but various modifications are possible. The R control signal is a signal proportional to the correction amount for determining the correction amount. If 0, the correction amount = 0, and the larger the numerical value, the larger the R correction signal value. The correction amount is maximized.

  The representative values of the R control signal generated based on the R signal and the R reference signal in this example are the same as those in Table 7.

  When the R control signal generation means 40 is a lookup table system or a system equivalent thereto, the R reference signal generation means 30 may not be provided or may be incorporated in the lookup table means, as described above. R control signal can be obtained.

The G correction signal generation means 51 is uniquely determined according to the G signal value, the B signal value, and the R control signal value, that is, the correction signal is related to the magnitude of the G signal value and the B signal value. A correction signal for determining the magnitude of the value is generated, and the magnitude of the correction signal is controlled by the R control signal and output to the G correction means 61. The G correction signal generating means 51 generates a G correction signal that tends to be proportional to the B signal value, inversely proportional to the G signal value, and proportional to the R control signal.
As an example of the calculation in which the G correction signal generation means 51 generates a correction signal,
GK1 is a desired coefficient, for example 2.5,
GK2 is a desired coefficient, for example 5,
The input G signal is G, where G is 0 to 255,
When the input B signal is B, where B is 0 to 255,
When (B− (G × GK1)) is a negative value, the generated G correction signal is 0,
When (B− (G × GK1)) is a positive value,
G correction signal = ((B− (G × GK1)) ÷ GK2) × R control signal,
A G correction signal is generated.
GK1 and GK2 are coefficients that are desired when generating the correction signal and can be changed. When the value is decreased, the generated correction signal is increased. When the value is increased, the generated correction signal is decreased. . By appropriately setting this coefficient, it is possible to adjust the correction amount and the correction range, and it is effectively corrected in a hard-to-see area where it is difficult for a person with color blindness to be distinguished. It is possible to appropriately set a range in which it is possible to achieve both the uncorrected and uncomfortable feeling for a healthy person.

Based on the input B signal and G signal, the G correction signal generation means 51 does not generate a correction signal when the B signal value is smaller than the value obtained by multiplying the G signal value by a desired coefficient GK1, and the B signal value Is larger than a value obtained by multiplying the G signal value by a desired coefficient GK1, a G correction signal is generated.

The G correction signal is generated as the B signal value increases or the G signal value decreases. Conversely, the G correction signal is generated as the B signal value decreases or the G signal value increases. An operation in which the signal value is small, that is, proportional to the B signal value, inversely proportional to the G signal value, and further, the correction signal value and the correction range are adjusted from the relationship between the B signal value and the G signal value by the coefficient GK1. The magnitude is adjusted by dividing the result by the desired coefficient GK2, and the magnitude of the value is controlled by the R control signal, that is, G is inversely proportional to the desired coefficient GK2 and proportional to the R control signal. A correction signal is generated and output to the G correction means 61.
Therefore, the G correction signal is proportional to the B signal value, is inversely proportional to the G signal value, and the correction signal value and the correction range are appropriately set based on the relationship between the B signal value and the G signal value by the coefficient GK1, It has a tendency to be inversely proportional to the desired coefficient GK2 and proportional to the R control signal. That is, a correction range is appropriately set based on the relationship between the coefficient, the B signal, and the G signal, and is proportional to the B signal value. It is inversely proportional, proportional to the R control signal, and has a tendency to adjust the value by a coefficient.

  The representative values of the G correction signal generated based on the B signal, the G signal, and the R control signal in this example are the same as those in Table 8.

  Note that even if the G correction signal generation means 51 is a lookup table method or a method equivalent thereto, it tends to be proportional to the B signal value and inversely proportional to the G signal value. The G control signal whose size is controlled can be generated.

この表９では上述したように、Ｇ信号値が基準信号値未満であるときに、Ｂ信号値に比例し、且つ、Ｒ信号値に逆比例したＲ補正信号を生成し、そのＲ補正信号をＲ信号に付加する補正を行った補正後の値を示す。同様に、Ｒ信号値が基準信号値未満であるときに、Ｂ信号値に比例し、且つ、Ｇ信号値に逆比例したＧ補正信号を生成し、そのＧ補正信号をＧ信号に付加する補正を行った補正後の値を示す。又、補正のない部分では、元の信号がそのまま出力されている。 The R correction unit 60 performs correction by adding the R signal from the input terminal 20 based on the R correction signal from the R correction signal generation unit 50, and outputs the corrected signal to the output terminal 70.
The G correction unit 61 performs correction by adding the G signal from the input terminal 21 based on the G correction signal from the G correction signal generation unit 51, and outputs the corrected signal to the output terminal 71.
The representative values of the R signal corrected by the R correction signal of this example and the representative values of the G signal corrected by the G correction signal are shown in the following Table 9 and FIG.

As described above in Table 9, when the G signal value is less than the reference signal value, an R correction signal that is proportional to the B signal value and inversely proportional to the R signal value is generated, and the R correction signal is The value after correction | amendment which performed the correction added to R signal is shown. Similarly, when the R signal value is less than the reference signal value, a G correction signal proportional to the B signal value and inversely proportional to the G signal value is generated, and the G correction signal is added to the G signal. The value after correction performed. In addition, the original signal is output as it is in a portion without correction.

As a result, in this embodiment for correcting dark blue, when correcting the R signal, a correction signal related to the magnitude of the values of the R signal and the B signal is generated, and when the G signal is 0, the correction is performed. The control signal for controlling the amount is 1, that is, the G signal is dark blue because there is no G signal, and the R signal is corrected. As the G signal approaches the reference signal value from 0, the correction amount decreases. If the signal value is greater than or equal to the signal value, the control signal for controlling the correction amount is 0, that is, the G signal is equal to or greater than the reference signal value and is not dark blue.
When correcting the G signal, a correction signal related to the magnitude of the values of the G signal and the B signal is generated. When the R signal is 0, the control signal for controlling the correction amount is 1, that is, the R signal. Since there is no dark blue, the G signal is corrected and the correction amount decreases each time the R signal approaches the reference signal value from 0. When the R signal is equal to or higher than the reference signal value, for example, a control signal for controlling the correction amount Is 0, that is, no correction is made because the R signal is greater than the reference signal value and not dark blue.

Therefore, when correcting dark blue, large correction signals and control signal values are generated, so large correction is performed. When R signal = 0, G signal = 0, and B signal = 255 are input, 51 is generated as the correction signal value, and can be corrected to R signal = 51, G signal = 51, and B signal = 255.
In the case of blue but other color components, R signal = 102, G signal = 0, B signal = 255, R signal = 0, G signal = 102, and B signal = 255. Alternatively, no correction is performed because no control signal is generated.
Further, when R signal = 0, G signal = 0, and B signal = 230 are input, 46 is generated as respective correction signal values, and corrected to R signal = 46, G signal = 46, and B signal = 230,
When R signal = 0, G signal = 0, and B signal = 204 are input, 41 is generated as each correction signal value, and corrected to R signal = 41, G signal = 41, and B signal = 204,
When R signal = 26, G signal = 26, and B signal = 255 are input, 28 are generated as respective correction signal values, and corrected to R signal = 54, G signal = 54, and B signal = 255,
When R signal = 51, G signal = 51, and B signal = 255 are input, 13 are generated as respective correction signal values, and can be corrected to R signal = 64, G signal = 64, and B signal = 255. .

Further, in the R correction signal generation means 50 of this embodiment, the correction range is set by the calculation result of (B− (R × RK1)), but the R reference set in advance for other R signals. Even if a correction signal is generated with a signal value, for example, an R signal value of less than 102 (40%), the same effect can be obtained.
Further, the correction amount is determined by the calculation result of ((B− (R × RK1)) ÷ RK2) × G control signal, but is proportional to the other B signal value and inversely proportional to the R signal value. The same applies to a means for adjusting the magnitude by calculating with some coefficients in proportion to the control signal (inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value). An effect is obtained.
Accordingly, a new R reference signal value for the R signal is preset in the R correction signal generating means 50, and is proportional to the B signal value and inversely proportional to the R signal value, and the difference between the R signal value and the R reference signal value. A means for adjusting the magnitude by calculating with some coefficients, proportional to the G control signal (inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value). The same effect can be obtained.
For example, R reference signal value is RS,
When a signal that is inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value is used as the R control signal,
R control signal = ((RS−R) ÷ RS), where the R control signal is 0 to 1,
G reference signal value is GS,
G control signal = ((GS−G) ÷ GS), where the G control signal is an example of 0 to 1,
R correction signal = ((B ÷ coefficient) × R control signal) × G control signal, that is,
R correction signal = ((B ÷ RK2) × ((RS−R) ÷ RS)) × (GS−G) ÷ GS),
The same effect can be obtained.

Further, in the G correction signal generation means 51 of the present embodiment, the correction range is set by the calculation result of (B− (G × GK1)), but the G reference set in advance for other G signals. Even if the correction signal is generated when the signal value, for example, the G signal value is less than 102 (40%), the same effect can be obtained.
Further, the correction amount is determined by the calculation result of ((B− (G × GK1)) ÷ GK2) × R control signal, but is proportional to the other B signal values and inversely proportional to the G signal value, and R The same applies to a means for adjusting the magnitude by calculating with some coefficients in proportion to the control signal (inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value). An effect is obtained.
Accordingly, a new G reference signal value for the G signal is preset in the G correction signal generating means 51, and is proportional to the B signal value and inversely proportional to the G signal value. Proportional to the difference value, proportional to the R control signal (inversely proportional to the R signal value and proportional to the difference value between the R signal value and the R reference signal value), and the size is adjusted by calculation using several coefficients. Similar effects can be obtained as a means.
For example, the G reference signal value is GS,
When a signal that is inversely proportional to the G signal value and proportional to the difference value between the G signal value and the G reference signal value is used as the G control signal,
G control signal = ((GS−G) ÷ GS), where the G control signal is 0 to 1,
R reference signal value is RS,
R control signal = ((RS−R) ÷ RS), where R control signal is an example of 0 to 1,
G correction signal = ((B ÷ coefficient) × G control signal) × R control signal, that is,
G correction signal = ((B ÷ GK2) × ((GS−G) ÷ GS)) × (RS−R) ÷ RS),
The same effect can be obtained.
Further, for example, RS is a preset reference signal value 102,
GS is a preset reference signal value 102,
GK2 is a desired coefficient, and when it is set to 5 as an example, the value of the generated R correction signal or G correction signal is
When B signal = 255, R signal = 0, and G signal = 0, 51 is generated as a correction signal value,
When B signal = 230, R signal = 0, and G signal = 0, 46 is generated as a correction signal value,
When B signal = 204, R signal = 0, and G signal = 0, 41 is generated as a correction signal value,
When B signal = 255, R signal = 26, and G signal = 26 are input, 28 is generated as a correction signal value,
When B signal = 255, R signal = 51, and G signal = 51 are input, 13 is generated as a correction signal value,
When the B signal = 255, the R signal = 102, the G signal = 0, the R signal = 255, the G signal = 0, and the B signal = 102, no correction signal is generated, and the same effect can be obtained.

As described above, when correcting the R signal, the G control signal generated based on the G signal value and the G reference signal value, the correction signal generated by the R signal value and the B signal value, It is possible to perform correction by changing the correction amount according to.
This corrects only dark blue, generates an R correction signal that tends to be proportional to the B signal value and inversely proportional to the R signal value or the G signal value. A correction added to the signal is performed to change the appearance of blue. That is, the larger the B signal value, which is dark blue, or the smaller the R signal value or G signal value, the larger the R correction signal is added. Conversely, the smaller the B signal value, or the larger the R signal value or G signal value, the smaller the correction amount. Further, if the G signal is greater than the desired reference signal value, no correction signal is generated.
When correcting the G signal, the correction amount is set according to the R control signal generated based on the R signal value and the R reference signal value, and the correction signal generated based on the G signal value and the B signal value. It can be corrected by changing.
This corrects only dark blue, generates a G correction signal that tends to be proportional to the B signal value and is inversely proportional to the R signal value or the G signal value. A correction added to the signal is performed to change the appearance of blue. That is, as the B signal value, which is dark blue, increases, or as the R signal value or G signal value decreases, a larger correction amount of G correction signal is added. Conversely, the smaller the B signal value, or the larger the R signal value or the G signal value, the smaller the correction amount. Further, if the R signal is greater than the desired reference signal value, no correction signal is generated.
For this reason, a person suffering from third color blindness is effectively corrected in an area where it is difficult to discern, and an area where the R signal or G signal is greater than a desired reference signal value is not corrected, so that a healthy person also feels strange An image signal correction method is executed that makes it possible to achieve both reduction in the size of the image signal.

  Note that the number of quantization bits representing the three primary color signals is a desired number of bits other than 8 bits, or a desired number of bits other than 8 bits, and a quantization method including a sign bit that can represent negative However, the same effect can be obtained.

  Furthermore, even if the coefficients such as RK1, RK2, BK1, BK2, GK1, and GK2 used in the description in the embodiment are other desired values, an effect can be obtained.

  The control signal generation means and the correction signal generation means can perform desired correction by using an input / output comparison table to correct digitized gradation data, which is a lookup table method, to an arbitrary gradation. Depending on the value, it is possible to generate a correction value having a desired linear or curvilinear output characteristic with respect to the input, and it is possible to generate a correction signal in which the value is uniquely determined for the input and the output, and the same effect can be obtained.

Further, the color space represented by the image signal is an sRGB color system and a color system that can be uniquely converted, for example, an RGBA color system, a YIQ color system, a YCbCr color system, or a YPbPr color system, Alternatively, the same effect can be obtained even when correction is performed in the XYZ color system, the xyY color system, or the xvYCC color system.
Furthermore, the above embodiment can be applied to the case of using other colors. For example, similar image signal processing corresponding to weak colors can be performed for yellow, magenta, cyan, and the like used for image formation.

In the present invention, when correcting a desired color signal among the R signal, G signal, and B signal, which are the three primary color signals of the image signal, the desired color signal value and the color signal value other than the desired color signal are changed. A corresponding correction signal is generated, and the magnitude of the correction signal is controlled by a control signal generated from a color signal value other than the two colors and a desired reference signal value, and the input image signal is corrected and output. Since this is the operation method of the image signal correction means to
Only the dark red is corrected, and a G correction signal or B correction signal that tends to be proportional to the R signal value and inversely proportional to the G signal value or the B signal value is generated. The correction of adding to the G signal or the correction of adding the B correction signal to the B signal can be performed to change the appearance of red.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate, and is not corrected in the area where the G signal or the B signal is higher than the desired reference signal value, the healthy person also feels uncomfortable. Therefore, it is possible to execute an image signal correction method that makes it possible to achieve both reduction in the size of the image signal.
Furthermore, correction is performed only for dark green, and a B correction signal that tends to be proportional to the G signal value and inversely proportional to the R signal value or the B signal value is generated, and this B correction signal is converted into the B signal. It is possible to change the appearance of green by performing additional correction.
For this reason, since the person who suffers from the first color blindness is effectively corrected in the hard-to-see area that is difficult to discriminate and is not corrected in the area where the R signal or the B signal is equal to or higher than the desired reference signal value, the healthy person also feels uncomfortable. Therefore, it is possible to execute an image signal correction method that makes it possible to achieve both reduction in the size of the image signal.
Furthermore, correction is performed only for dark blue, and an R correction signal or a G correction signal that tends to be proportional to the B signal value and is inversely proportional to the R signal value or the G signal value is generated. Correction of adding a signal to the R signal or correction of adding a G correction signal to the G signal can be performed to change the appearance of blue.
For this reason, a person suffering from third color blindness is effectively corrected in an area where it is difficult to discern, and an area where the R signal or G signal is higher than the desired reference signal value is not corrected, so that a healthy person also feels uncomfortable. Therefore, it is possible to execute an image signal correction method that makes it possible to achieve both reduction in the size of the image signal.
Therefore, an image display that is difficult to distinguish and difficult to see for persons suffering from the first color blindness or the third color blindness is effectively color-corrected only in a difficult-to-see region that is difficult to distinguish, and a region that is greater than a desired reference signal value Then, since the correction is not performed, it is possible to provide a display device characterized in that both a sense of incongruity can be reduced for a healthy person and that both can be achieved.

DESCRIPTION OF SYMBOLS 10 Image signal correction means 10A Image signal correction means 10B Image signal correction means 20 Input signal R input terminal 21 Input signal G input terminal 22 Input signal B input terminal 30 R reference signal generation means 31 G reference signal generation means 32 B Reference signal generation means 40 R control signal generation means 41 G control signal generation means 42 B control signal generation means 50 R correction signal generation means 51 G correction signal generation means 52 B correction signal generation means 60 R correction means 61 G correction means 62 B Correction means 70 Output signal R output terminal 71 Output signal G output terminal 72 Output signal B output terminal

Claims (6)

An R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals;
B reference signal generating means for generating and outputting a desired B reference signal for the B signal;
G reference signal generating means for generating and outputting a desired G reference signal for the G signal;
B control signal generating means connected to the B input terminal and generating a B control signal based on an input B signal and a B reference signal value, and outputting the B control signal to a subsequent stage;
G control signal generating means connected to the G input terminal and generating a G control signal based on an input G signal and a G reference signal value;
G connected to the R input terminal, the G input terminal, and the B control signal generating means, generates a G correction signal for the G signal based on the input R signal, G signal, and B control signal, and outputs the G correction signal to the subsequent stage. Correction signal generation means;
B connected to the R input terminal, the B input terminal, and the G control signal generation means, generates a B correction signal for the B signal based on the input R signal, B signal, and G control signal, and outputs the B correction signal to the subsequent stage. Correction signal generation means;
G correction means connected to the G input terminal and G correction signal generation means, for correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The B control signal generating means does not generate a B control signal when the B signal value is larger than the B reference signal value, and generates a B control signal when the B signal value is smaller than the B reference signal value. The B control signal generates a B control signal that is inversely proportional to the B signal value and proportional to a difference value between the B signal value and the B reference signal value;
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The G correction signal generation means does not generate a G correction signal when the R signal value is smaller than the G signal value multiplied by the desired coefficient GK1, and the R signal value increases the G signal value by the desired coefficient GK1. If it is greater than the value, a G correction signal is generated,
The G correction signal is generated as the R signal value is larger or the G signal value is smaller. Conversely, the G correction signal is generated as the R signal value is smaller or the G signal value is larger. The signal value is small, that is, proportional to the R signal value and inversely proportional to the G signal value, and further, the correction signal value and the correction range are determined from the relationship between the R signal value and the G signal value by the coefficient GK1. The operation result to be adjusted
The magnitude is adjusted by dividing by the desired coefficient GK2, and the magnitude of the value is further controlled by the B control signal, that is, G is inversely proportional to the desired coefficient GK2 and proportional to the B control signal. Generating a correction signal;
When the B correction signal generation means is smaller than the value obtained by multiplying the B signal value by the desired coefficient BK1, no B correction signal is generated, and the R signal value is multiplied by the desired coefficient BK by the B signal value. If greater than the value, generate a B correction signal,
The B correction signal is generated as the R signal value is larger or the B signal value is smaller. Conversely, the B correction signal is generated as the R signal value is smaller or the B signal value is larger. The signal value becomes smaller, that is, proportional to the R signal value and inversely proportional to the B signal value, and further, the correction signal value and the correction range are determined from the relationship between the R signal value and the B signal value by the coefficient BK1. The operation result to be adjusted
The magnitude is adjusted by dividing by the desired coefficient BK2, and the magnitude of the value is further controlled by the G control signal, that is, B is inversely proportional to the desired coefficient BK2 and proportional to the G control signal. Generating a correction signal;
A step in which the G correction means performs correction by adding the G correction signal to the input G signal, and outputs the corrected G signal;
A step in which the B correction means performs correction by adding the B correction signal to the input B signal, and outputs the corrected B signal;
The image signal correcting method of the image signal correcting means, characterized in that An R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals;
R reference signal generating means for generating and outputting a desired R reference signal for the R signal;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value, and outputting the R control signal to a subsequent stage;
B connected to the G input terminal, the B input terminal, and the R control signal generation means, generates a B correction signal for the B signal based on the input G signal, B signal, and R control signal, and outputs the B correction signal to the subsequent stage. Correction signal generation means;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G input terminal;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
When the B correction signal generating means is smaller than the value obtained by multiplying the B signal value by the desired coefficient BK1, no B correction signal is generated, and the G signal value is multiplied by the desired coefficient BK by the B signal value. If greater than the value, generate a B correction signal,
The B correction signal is generated as the G signal value is larger or the B signal value is smaller. On the contrary, as the G signal value is smaller or the B signal value is larger, the correction signal is generated. The value is small, that is, proportional to the G signal value and inversely proportional to the B signal value, and the correction signal value and the correction range are adjusted by the relationship between the G signal value and the B signal value by the coefficient BK1. The operation result
The magnitude is adjusted by dividing by the desired coefficient BK2, and the magnitude of the value is further controlled by the R control signal, that is, B is inversely proportional to the desired coefficient BK2 and proportional to the R control signal. Generating a correction signal;
A step in which the B correction means performs correction by adding the B correction signal to the input B signal, and outputs the corrected B signal;
The image signal correcting method of the image signal correcting means, characterized in that An R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals;
G reference signal generating means for generating and outputting a desired G reference signal for the G signal;
R reference signal generating means for generating and outputting a desired R reference signal for the R signal;
G control signal generating means connected to the G input terminal and generating a G control signal based on an input G signal and a G reference signal value;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value, and outputting the R control signal to a subsequent stage;
The R input terminal, the B input terminal, and the G control signal generating means are connected to generate an R correction signal for the R signal based on the input R signal, B signal, and G control signal, and output to the subsequent stage. Correction signal generation means;
G connected to the G input terminal, the B input terminal, and the R control signal generating means, and generates a G correction signal for the G signal based on the input G signal, the B signal, and the R control signal, and outputs the G correction signal to the subsequent stage. Correction signal generation means;
R correction means connected to the R input terminal and the R correction signal generating means, correcting the R signal input from the R input terminal based on the input R correction signal, and outputting a corrected signal;
G correction means connected to the G input terminal and the G correction signal generating means, correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R correction means;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B input terminal,
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
When the R correction signal generating means has a B signal value smaller than a value obtained by multiplying the R signal value by a desired coefficient RK1, no R correction signal is generated, and the B signal value is obtained by multiplying the R signal value by a desired coefficient RK1. If it is greater than the value, an R correction signal is generated,
The correction signal value generated as the B signal value increases or the R signal value decreases as the R correction signal increases. Conversely, the correction signal value generated as the B signal value decreases or the R signal value increases. Is smaller, that is, proportional to the B signal value and inversely proportional to the R signal value, and the correction signal value and the correction range are adjusted from the relationship between the B signal value and the R signal value by the coefficient RK1. The operation result
The magnitude is adjusted by dividing by the desired coefficient RK2, and the magnitude of the value is further controlled by the G control signal, that is, inversely proportional to the desired coefficient BK2 and proportional to the G control signal. Generating a correction signal;
The G correction signal generation means does not generate a G correction signal when the B signal value is smaller than the value obtained by multiplying the G signal value by the desired coefficient GK1, and the B signal value increases the G signal value by the desired coefficient GK1. If it is larger than the value, a G correction signal is generated,
The G correction signal has a larger correction signal value generated as the B signal value is larger or smaller, and conversely, a correction signal value generated as the B signal value is smaller or the G signal value is larger. Is smaller, that is, proportional to the B signal value and inversely proportional to the G signal value, and further, the correction signal value and the correction range are adjusted from the relationship between the B signal value and the G signal value by the coefficient GK1. The operation result
The magnitude is adjusted by dividing by the desired coefficient GK2, and the magnitude of the value is controlled by the R control signal, that is, inversely proportional to the desired coefficient GK2 and proportional to the R control signal. Generating a correction signal;
A step in which the R correction means performs correction by adding the R correction signal to the input R signal, and outputs the corrected R signal;
A step in which the G correction means performs correction by adding the G correction signal to the input G signal, and outputs the corrected G signal;
The image signal correcting method of the image signal correcting means, characterized in that An R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals;
B control signal generating means connected to the B input terminal and generating a B control signal based on a B signal inputted and a B reference signal value set in advance in advance;
G control signal generating means connected to the G input terminal, for generating a G control signal based on a G signal inputted and a G reference signal value set in advance, and outputting the G control signal to a subsequent stage;
Connected to the R input terminal, the G input terminal, and the B control signal generating means, and based on the R signal, the G signal, the B control signal, and the G reference signal value set in advance in advance, G correction signal generation means for generating a G correction signal and outputting it to a subsequent stage;
Connected to the R input terminal, the B input terminal, and the G control signal generating means, and based on the input R signal, B signal, G control signal, and a B reference signal value set in advance in advance, B correction signal generation means for generating a B correction signal and outputting it to a subsequent stage;
G correction means connected to the G input terminal and the G correction signal generating means, for correcting the G signal inputted from the G input terminal based on the inputted G correction signal, and outputting a corrected signal;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The B control signal generating means does not generate a B control signal when the B signal value is larger than the B reference signal value, and generates a B control signal when the B signal value is smaller than the B reference signal value. The B control signal generates a B control signal that is inversely proportional to the B signal value and proportional to a difference value between the B signal value and the B reference signal value;
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The G correction signal generating means does not generate a correction signal when the G signal is larger than the G reference signal value based on the R signal, the G signal, the G reference signal value set in advance and the B control signal. When the G signal is smaller than the G reference signal, a G correction signal is generated,
The G correction signal is proportional to the R signal value, is inversely proportional to the G signal value, is proportional to the difference value between the G signal value and the G reference signal value, and is proportional to the B control signal, And a step in which the calculation is performed with a desired coefficient and the magnitude of the value is adjusted to generate the B correction signal generating means, the R signal, the B signal, a preset B reference signal value, and a G control signal. If the B signal is larger than the B reference signal value, no correction signal is generated. If the B signal is smaller than the B reference signal, a B correction signal is generated.
The B correction signal is proportional to the R signal value, inversely proportional to the B signal value, proportional to the difference value between the B signal value and the B reference signal value, and proportional to the G control signal, And a step of generating by adjusting the magnitude of the value by calculating with a desired coefficient. The G correction unit performs correction by adding the G correction signal to the input G signal, and the corrected G signal is obtained. Output step,
A step in which the B correction means performs correction by adding the B correction signal to the input B signal, and outputs the corrected B signal;
The image signal correcting method of the image signal correcting means, characterized in that An R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value set in advance, and outputting the R control signal to a subsequent stage;
Connected to the G input terminal, the B input terminal, and the R control signal generating means, and based on the input G signal, B signal, R control signal, and a preset B reference signal value, B correction signal generation means for generating a B correction signal and outputting it to a subsequent stage;
B correction means connected to the B input terminal and the B correction signal generating means, correcting the B signal input from the B input terminal based on the input B correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R input terminal;
A G output terminal for outputting a G signal connected to the G input terminal;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B correction unit,
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
The B correction signal generation means does not generate a correction signal when the B signal is larger than the B reference signal value based on the G signal, the B signal, the B reference signal value set in advance and the R control signal. When the B signal is smaller than the B reference signal, a B correction signal is generated,
The B correction signal is proportional to the G signal value, inversely proportional to the B signal value, proportional to the difference value between the B signal value and the B reference signal value, and proportional to the R control signal, And a step generated by calculating with the desired coefficient and adjusting the magnitude of the value. The B correction means performs correction by adding the B correction signal to the input B signal, and the corrected B signal is obtained. Output step,
The image signal correcting method of the image signal correcting means, characterized in that An R input terminal, an G input terminal, and a B input terminal for inputting an image signal composed of an R signal, a G signal, and a B signal that are three primary color signals;
G control signal generating means connected to the G input terminal, for generating a G control signal based on a G signal inputted and a G reference signal value set in advance, and outputting the G control signal to a subsequent stage;
R control signal generating means connected to the R input terminal and generating an R control signal based on an input R signal and an R reference signal value set in advance, and outputting the R control signal to a subsequent stage;
Connected to the R input terminal, the B input terminal, and the G control signal generating means, and based on the input B signal, R signal, G control signal, and an R reference signal value set in advance in advance, R correction signal generation means for generating an R correction signal and outputting it to a subsequent stage;
Connected to the G input terminal, the B input terminal, and the R control signal generating means, and based on the input B signal, G signal, R control signal, and a G reference signal value set in advance in advance, G correction signal generation means for generating a G correction signal and outputting it to a subsequent stage;
R correction means connected to the R input terminal and the R correction signal generating means, correcting the R signal input from the R input terminal based on the input R correction signal, and outputting a corrected signal;
G correction means connected to the G input terminal and the G correction signal generating means, correcting the G signal input from the G input terminal based on the input G correction signal, and outputting a corrected signal;
An R output terminal for outputting an R signal connected to the R correction means;
A G output terminal for outputting a G signal connected to the G correction means;
An image signal correction method performed by an image signal correction unit including a B output terminal that outputs a B signal connected to the B input terminal,
The G control signal generation means does not generate a G control signal when the G signal value is larger than the G reference signal value, and generates a G control signal when the G signal value is smaller than the G reference signal value. The G control signal generates a G control signal that is inversely proportional to the G signal value and proportional to a difference value between the G signal value and the G reference signal value;
The R control signal generating means does not generate an R control signal when the R signal value is larger than the R reference signal value, and generates an R control signal when the R signal value is smaller than the R reference signal value. The R control signal generates an R control signal that is inversely proportional to the R signal value and proportional to a difference value between the R signal value and the R reference signal value;
The R correction signal generating means does not generate a correction signal when the R signal is larger than the R reference signal value based on the B signal, the R signal, the R reference signal value set in advance and the G control signal. When the R signal is smaller than the R reference signal, an R correction signal is generated,
The R correction signal is proportional to the B signal value, inversely proportional to the G signal value, proportional to the difference value between the G signal value and the G reference signal value, and proportional to the G control signal, Further, a step in which the calculation is performed with a desired coefficient and the magnitude of the value is adjusted, and the G correction signal generation means includes a B signal, a G signal, a G reference signal value set in advance, and an R control signal. If the G signal is larger than the G reference signal value, no correction signal is generated. If the G signal is smaller than the G reference signal, a G correction signal is generated.
The G correction signal is proportional to the B signal value, inversely proportional to the G signal value, proportional to the difference value between the G signal value and the G reference signal value, and proportional to the R control signal, And a step generated by adjusting the magnitude of the value by calculating with a desired coefficient. The R correction means performs correction by adding the R correction signal to the input R signal, and the corrected R signal is obtained. Output step,
A step in which the G correction means performs correction by adding the G correction signal to the input G signal, and outputs the corrected G signal;
The image signal correcting method of the image signal correcting means, characterized in that

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