JP2003241731A - Circuit and method for video signal correction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an improved circuit and a method for video signal correction by correcting a color blurring generated when a digital video signal is displayed on a display through digital signal processing by interpolation. <P>SOLUTION: A video signal correcting circuit 1 is constituted so that it generates a corrected R signal corrected by interpolation from R signals of two pixels, i.e., an R signal and R signals constituting pixels, adjacent to the R signal by an R signal correcting means 2, generates a delayed G signal by a G signal phase correcting means 3 by delaying the output timing of a G signal by cycles of one pixel, and generates a corrected B signal corrected by interpolation from B signals of two pixels, i.e., a B signal and B signals constituting adjacent pixels, adjacent to the B signal by a B signal correcting means 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal correction circuit and a video signal correction method for improving color fringing that occurs when a digital video signal is displayed on a pixel structure display such as a liquid crystal display and a plasma display (PDP). Regarding

[0002]

2. Description of the Related Art Generally, a personal computer (PC)
A display used as a display device such as a display device uses red (R) signals, G (green) signals, and B (blue) signals (RG), which are digital image signals, for each of the three primary colors of red, green, and blue.
A pixel structure display having a pixel structure in which unit pixels output as B signals) are arranged is used. This R
The GB signal is mixed as light (additive color mixture) and is viewed by the human eye as one color.

This pixel structure display is shown in FIG.
As shown in FIG. 13A, a unit pixel having a stripe-shaped pixel structure in which unit pixels are arranged in the order of RGB, and FIG.
As shown in (b), there are pixels having a mosaic pixel structure in which the RGB order of the unit pixels differs depending on the vertical position of the screen.

[0004]

However, in the above-described display having a pixel structure having a stripe structure or a mosaic structure, color bleeding may be noticeable in a region where the signal levels of R, G and B signals change abruptly. .

Color bleeding will be described with reference to FIG. For example, in a display having a stripe structure, as shown in FIG. 14A, R, G, and B signals of each unit pixel are displayed in a region where the maximum signal level (maximum gradation value) is displayed. When an area having the minimum signal level (minimum gradation value) of the G and B signals is displayed, FIG.
As shown in (b), the area of the highest signal level is viewed as a "white" color and the area of the lowest signal level is viewed as a "black" color. At this time, the region BL and the region RD which are in contact with the region visualized in the “black” color and which should be visualized in the “white” color may appear blurred in the “blue” color or the “red” color.

Originally, when the unit pixel is originally represented by the R, G, and B signals, it is ideal that the respective signals are output from the same position and displayed as the unit pixel. On the other hand, due to the structure of the display, This is because the R, G, and B signals are output from spatially different positions and displayed as unit pixels. That is, the R, G and B signals are RG
In the display arranged and output in the order of B,
Since the R and B signals are shifted by ⅓ pixel from the G signal arranged between the respective signals, the area BL
May appear bleeding into a “blue” color due to the influence of the B signal, and similarly, the region RD may be blurred due to the influence of the R signal.
It may appear bleeding in the "red" color.

Further, this problem also exists in a display having a mosaic structure, and as in the above, "white",
When the “black” color area is displayed, due to the influence of the “white” R, G, or B signal in contact with the “black” color,
It may appear blurred in "red", "green" or "blue" colors. In addition, since workers who perform word processing, spreadsheets, and CAD on a personal computer or the like often see the display close up, color bleeding becomes more noticeable. Such color bleeding becomes an obstacle when accurately displaying a fine straight line such as CAD.

The present invention has been made to solve the above problems, and an image improved by correcting color bleeding that occurs when a digital image signal is displayed on a display by digital signal processing by interpolation. An object is to provide a signal correction circuit and a video signal correction method.

[0009]

SUMMARY OF THE INVENTION The present invention was conceived to achieve the above object. First, the video signal correction circuit according to claim 1 is the first and the third primary colors. Colors in a pixel structure display having a pixel structure in which the unit pixels are arranged by correcting digital video signals input in time series with the second and third primary color signals as unit pixels in the horizontal direction for each unit pixel. A video signal correction circuit for reducing bleeding, wherein a signal level of a first primary color signal arranged at one end of a correction target pixel to be corrected by the unit pixel is set to a unit pixel adjacent to the first primary color signal. First signal correction means for correcting based on a signal level of a primary color signal of the same color as the first primary color signal in a certain first adjacent pixel, and a signal of a second primary color signal arranged at the other end of the correction target pixel Second signal correction means for correcting the bell based on the signal level of the primary color signal of the same color as the second primary color signal in the second adjacent pixel which is a unit pixel adjacent to the second primary color signal; The phase of the third primary color signal in the pixel to be corrected is delayed with respect to the respective phases of the first primary color signal corrected by the signal correction means and the second primary color signal corrected by the second signal correction means. And a phase delay means for synchronizing.

According to such a configuration, the video signal correction circuit causes the signal level of the first primary color signal arranged at one end of the pixel to be corrected by the first signal correction means to be 1 adjacent to the first primary color signal. The correction is performed so as to reduce the difference in signal level between the first primary color signal of the pixel and the signal level of the primary color signal of the same color that is input a period before.

For example, the signal level of the first primary color signal arranged at one end of the pixel to be corrected and the signal level of the primary color signal of the same color as the first primary color signal of the pixel input one cycle before are interpolated. By doing so, the new signal level interpolated is set as the signal level of the first primary color signal of the pixel to be corrected.

Further, in the video signal correction circuit, the signal level of the second primary color signal arranged at the other end of the pixel to be corrected is corrected by the second signal correction means for one cycle adjacent to the second primary color signal. The correction is performed so as to reduce the difference in signal level between the second primary color signal of the pixel input later and the signal level of the primary color signal of the same color.

For example, the signal level of the second primary color signal arranged at the other end of the pixel to be corrected and the signal level of the primary color signal of the same color as the second primary color signal of the pixel input one cycle later are interpolated. By doing so, the new signal level interpolated is set as the signal level of the second primary color signal of the pixel to be corrected.

Further, the video signal correction circuit outputs the third primary color signal in synchronization with the phases of the first primary color signal and the second primary color signal by the phase delay means. by this,
The video signal correction circuit generates a new digital video signal in which abrupt signal level changes between pixels are suppressed from the digital video signals input in time series.

The video signal correction circuit according to a second aspect of the present invention is the video signal correction circuit according to the first aspect, wherein the unit pixel is white based on the signal levels of the first, second and third primary color signals. Alternatively, a line width determination unit that determines that the line width is black or black and determines the white or black line width is provided, and the first and second signal corrections are performed based on the line width determined by the line width determination unit. The means adjusts the correction amount of the signal level.

According to this configuration, the video signal correction circuit determines the white or black line width by the line width determination means, and the thinner the line width, the more the signal levels in the first and second signal correction means. By setting a small correction amount of, the deterioration of the contrast of the white or black line due to this correction is suppressed.

Further, in the video signal correction circuit according to the present invention, the digital video signals input in time series with the R, G, and B signals which are the three primary colors of color as unit pixels are horizontally arranged in the unit pixels. A video signal correction circuit for reducing color fringing in a pixel structure display having a pixel structure in which the unit pixels are arranged, by correcting each of the unit pixels,
R signal correction means for correcting the signal level of the R signal of the correction target pixel which is the correction target of the unit pixel based on the signal level of the R signal in the first adjacent pixel which is the unit pixel adjacent to this R signal B signal correction means for correcting the signal level of the B signal of the correction target pixel based on the signal level of the B signal in the second adjacent pixel which is a unit pixel adjacent to the B signal, and the R signal correction G signal phase delay means for delaying and synchronizing the phase of the G signal in the pixel to be corrected with respect to the respective phases of the R signal corrected by the means and the B signal corrected by the B signal correcting means. It was configured.

According to such a construction, the video signal correction circuit inputs the signal level of the R signal arranged at one end of the pixel to be corrected by the R signal correction means by one cycle before the R signal. The correction is performed so as to reduce the difference between the R signal of the pixel and the signal level of the primary color signal of the same color. For example, a new signal level interpolated by interpolating the signal level of the R signal arranged at one end of the pixel to be corrected and the signal level of the R signal of the pixel input one cycle before is to be corrected. It is the signal level of the R signal of the pixel.

Further, in this video signal correction circuit, the B signal correction means causes the pixel level of the pixel which is input to the signal level of the B signal arranged at the other end of the pixel to be corrected after one cycle adjacent to the B signal. Correction is performed so as to reduce the difference between the signal level of the B signal and the signal level of the B signal. For example, a new signal level interpolated by interpolating the signal level of the B signal arranged at the other end of the pixel to be corrected and the signal level of the B signal of the pixel input after one cycle is to be corrected. It is the signal level of the B signal of the pixel.

Further, the video signal correction circuit outputs the G signal in synchronization with the phases of the R signal and the B signal by the phase delay means. As a result, the video signal correction circuit generates a new digital video signal in which abrupt signal level changes between pixels are suppressed from the digital video signal input in time series.

According to a fourth aspect of the present invention, there is provided a video signal correction circuit, wherein a digital video signal input in time series with first, second and third primary color signals which are the three primary colors of color as unit pixels,
A video signal correction circuit that reduces color fringing in a pixel structure display having a pixel structure in which the unit pixels are arranged by correcting each of the unit pixels in the horizontal direction, based on a synchronization signal of the digital video signal. ,
Vertical position determination means for determining the vertical position of the unit pixel, and the signal level of the primary color signal in the correction target pixel that is the target of correction of the unit pixel for each of the first, second and third primary color signals Is corrected based on a signal level of the same color as the primary color signal of the unit pixel input one cycle before the pixel to be corrected, and the phase of the primary color signal corrected by the signal correcting means is delayed. And a switching unit for switching whether to delay the primary color signal corrected by the signal correction unit by the phase delay unit, in the vertical direction of the unit pixel determined by the vertical position determination unit. On the basis of the position, the signal correction means adjusts the correction amount of the signal level and switches the switching means.

According to this structure, the video signal correction circuit causes the signal level of the primary color signal in the pixel to be corrected to be adjacent to the primary color signal by the signal correction means for each of the first, second and third primary color signals. The correction is performed so as to reduce the difference between the primary color signal of the pixel to be processed and the signal level of the primary color signal of the same color.
At this time, the vertical position determining means determines the vertical position based on the synchronization signal, determines the arrangement of the first, second, and third primary color signals in the unit pixel based on the position, and determines the unit. Only the primary color signals arranged at both ends of the pixel are corrected.

Further, the video signal correction circuit changes the phase of each primary color signal by operating or not operating the signal delay means for delaying the phase of the primary color signal based on the position in the vertical direction. Output in synchronization. For example, the signal correction unit interpolates a new signal by interpolating the signal level of the primary color signal of the pixel to be corrected and the signal level of the primary color signal of the same color as the primary color signal of the pixel adjacent to this primary color signal. The level is the signal level of the primary color signal of the pixel to be corrected.

Further, in the video signal correction circuit according to a fifth aspect, in the video signal correction circuit according to the fourth aspect, the unit pixel is determined based on the signal levels of the first, second and third primary color signals. A line width determination unit that determines whether the line width is white or black and determines the line width of the white or black is provided. Based on the line width determined by the line width determination unit, the signal correction unit determines the signal level of the signal level. The configuration is such that the correction amount is adjusted.

According to this structure, the video signal correction circuit determines the white or black line width by the line width determination means, and the smaller the line width, the smaller the correction amount is set. Suppresses the decrease in the contrast of white or black lines.

According to a sixth aspect of the present invention, there is provided a method for correcting a video signal, wherein digital video signals input in time series with the first, second and third primary color signals which are the three primary colors of color as unit pixels,
A video signal correction method for reducing color fringing in a pixel structure display having a pixel structure in which the unit pixels are arranged by correcting each of the unit pixels in the horizontal direction. The correction target based on the signal level of the same color as the first primary color signal arranged at one end of the correction target pixel in the first continuous pixel composed of two to four unit pixels continuous in the horizontal direction including the target pixel A first signal correction step of correcting the signal level of the first primary color signal of the pixel, and the correction target pixel in a second continuous pixel composed of two to four unit pixels continuous in the horizontal direction including the correction target pixel Based on the signal level of the same color as the second primary color signal arranged at the other end of
A second signal correction step for correcting the signal level of the second primary color signal of the pixel to be corrected, a first primary color signal corrected in the first signal correction step and a second signal correction step in the second signal correction step A phase delay step of delaying and synchronizing the phase of the third primary color signal in the pixel to be corrected with respect to each phase of the second primary color signal.

According to this method, the video signal correction method is
In the first signal correction step, the first primary color arranged at one end of the correction target pixel in the first continuous pixel composed of two to four unit pixels continuous in the horizontal direction including the correction target pixel to be corrected Based on the signal level of the same color as the signal, correction is performed so as to reduce the difference between the signal level of the first primary color signal arranged at one end of the correction target pixel and the signal level of the first primary color signal of the adjacent pixel. For example, in the first continuous pixel, a new signal level interpolated by interpolating a signal level of the same color as the first primary color signal arranged at one end of the correction target pixel is used as a signal of the first primary color signal of the correction target pixel. Level.

Further, according to this video signal correction method, in the second signal correction step, in addition to the correction target pixel in the second continuous pixel composed of 2 to 4 unit pixels continuous in the horizontal direction including the correction target pixel, Based on the signal level of the same color as the second primary color signal arranged at the end, the difference between the second primary color signal arranged at the other end of the correction target pixel and the signal level of the second primary color signal of the adjacent pixel is reduced. Make corrections. For example, in the second continuous pixel, a new signal level interpolated by interpolating a signal level of the same color as the second primary color signal arranged at the other end of the correction target pixel is used as the second primary color signal of the correction target pixel. Signal level.

Further, in this video signal correcting method, the third primary color signal is output in synchronization with the phases of the first primary color signal and the second primary color signal by the phase delay step. As a result, the video signal correction circuit generates a new digital video signal in which abrupt signal level changes between pixels are suppressed from the digital video signal input in time series.

Further, the video signal correction method according to claim 7 is the video signal correction method according to claim 6, wherein the line width determined by the line width determination means for determining the line width of the white or black line. Based on the above, the first and second signal correction steps include an adjustment step of adjusting the correction amount of the signal level.

According to this method, the video signal correction method is
The smaller the white or black line width determined by the line width determination means, the smaller the correction amount is set, thereby suppressing the reduction in the contrast of the white or black line due to this correction.

Further, in the video signal correction method according to the present invention, the digital video signals inputted in time series with the first, second and third primary color signals which are the three primary colors of the color as unit pixels,
A video signal correction method for reducing color fringing in a pixel structure display having a pixel structure in which the unit pixels are arranged by correcting each unit pixel in a horizontal direction, wherein the first, second and third primary colors are used. For each signal, a signal level of the same color as the primary color signal in the pixel to be corrected in a continuous pixel composed of two to four unit pixels continuous in the horizontal direction including the pixel to be corrected to be corrected in the unit pixel, A signal correction step of correcting the signal level of the primary color signal of the correction target pixel based on the vertical position determined by the vertical position determination means for determining the vertical position of the correction target pixel; And a phase delay step of delaying the phase of the primary color signal corrected by the signal correction step based on the position of.

According to this method, the video signal correction method is
For each of the first, second, and third primary color signals, in the signal correction step, the same color as the primary color signal in the correction target pixel in the two to four unit pixels consecutive in the horizontal direction including the correction target pixel to be corrected The signal level of the primary color signal in the pixel to be corrected is corrected based on the signal level of 1 to reduce the difference in signal level from the signal level of the primary color signal of the adjacent pixel. At this time, the arrangement of the first, second and third primary color signals in the unit pixel is recognized based on the position in the vertical direction determined by the vertical position determining means based on the synchronization signal, and both ends of the unit pixel are recognized. Only the arranged primary color signals are corrected.

Further, according to this video signal correction method, the phase of each primary color signal is synchronized by switching whether the signal delay step for delaying the phase of the primary color signal is operated or not based on the position in the vertical direction. And output. For example, in the signal correction step, a new signal level interpolated by interpolating the signal level of the same color as the primary color signal in the correction target pixel in the continuous pixels is set as the signal level of the primary color signal in the correction target pixel.

Furthermore, the video signal correction method according to claim 9 is the video signal correction method according to claim 6, wherein the line width determined by the line width determination means for determining the line width of the white or black line. Based on the above, the signal correction step includes an adjustment step of adjusting the correction amount of the signal level.

According to this method, the video signal correction method is
The smaller the white or black line width determined by the line width determination means, the smaller the correction amount is set, thereby suppressing the reduction in the contrast of the white or black line due to this correction.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing the overall configuration of a video signal correction circuit according to the first embodiment of the present invention. As shown in FIG. 1, the video signal correction circuit 1
Is an R signal correction means 2, a G signal phase delay means 3, and a B signal
The signal correction means 4 is included. The video signal correction circuit 1 inputs R, G and B signals which are digital video signals, corrects and delays the respective signals,
It is a circuit that generates a corrected R signal, a delayed G signal, and a corrected B signal with reduced color fringing. The video signal correction circuit 1 in this embodiment is a circuit that reduces color fringing in a display having a pixel structure in which unit pixels are arranged and output in the order of R, G, and B signals.

The R signal correcting means 2 divides the input R signal and the R signal constituting the pixel adjacent to the R signal into two.
A corrected R signal corrected by interpolation is generated from the R signal for pixels. The R signal correction means 2 includes an inverse gamma correction unit 10 (10a), a delay unit 11 (11a and 11b), a multiplication unit 12 (12a and 12b), an addition unit 13 (13a), and a gamma correction unit 14. (14a).

The G signal phase delay means 3 delays the input G signal by delaying the output timing by the period of one pixel.
It is for generating a signal. This G signal phase delay means 3
Is an inverse gamma correction unit 10 (10b) and a delay unit 11 (1
1c) and a gamma correction unit 14 (14b). The G signal phase delay means 3 is shown in FIG.
As is apparent from the above, the inverse gamma correction unit 10 (10b) and the gamma correction unit 14 (14b) may be omitted as a pair.

The B signal correcting means 4 divides the input B signal and the B signal forming the pixel adjacent to the B signal into two.
A corrected B signal corrected by interpolation is generated from the B signal for pixels. The B signal correction means 4 includes an inverse gamma correction unit 10 (10c) and a delay unit 11 (11d).
, The multiplication unit 12 (12c and 12d), and the addition unit 13
(13b) and the gamma correction unit 14 (14c).

The inverse gamma correction unit 10 generates a linear digital video signal by correcting the input non-linear digital video signal corrected by the gamma characteristic of the display with the inverse characteristic of the gamma characteristic. is there.
As a result, the signal level of the digital video signal before gamma correction is generated. The delay unit 11 delays the output timing of the digital video signal input to the delay unit 11 by the period of one pixel. The delay unit 11 can be realized by a general delay circuit.

The multiplying unit 12 converts the signal level (amplitude) of the digital video signal input to the multiplying unit 12 into a preset ratio and outputs it. This multiplication unit 12
Can be realized by a general multiplication circuit. Here, the multiplication units 12a and 12d reduce the signal level by setting the ratio to 1/3 and the multiplication units 12b and 12c set the ratio to 2/3. The ratio is set as an interpolation coefficient for interpolating the signal level between pixels. The interpolation coefficient represents a numerical value by which the magnitude of each signal level is multiplied when the signal level between two signals is interpolated by interpolation to generate a new signal level.

Interpolation will now be described with reference to FIG. FIG. 2A is a diagram schematically showing the interpolation of the R signal in the pixel structure arranged in the order of RGB. Further, P1 and P2 represent the center position of each pixel. FIG. 2B is a diagram schematically showing the interpolation of the B signal in the pixel structure arranged in the order of RGB.

As shown in FIG. 2 (a), image data etc. sent to the display are R, G like P1 and P2.
And B signals are assumed to be displayed at the same position. However, since the R, G, and B signals are output from spatially different positions, for example, the R ₂ signal of P2 is P3.
Is displayed at the position. That is, the R ₂ signal is displayed with a shift of 1/3 pixel from the assumed position (P2). Therefore, the signal levels of the R ₁ and R ₂ signals are set to 1/3 pixel and 2
Interpolation is performed by interpolation with / 3 pixel to generate a signal level (correction R ₂ ) of the R ₂ signal in which the pixel shift is corrected. Thus corrected R ₂ includes a signal level of the R ₂ signal is generated by R (R ₁₎ signals included in a pixel adjacent to the R ₂ signal (1 cycle before the pixels of the pixel).

Further, as shown in FIG. 2B, the signal level of the B signal can be corrected by interpolation similarly to the R signal to generate a signal. However, the signal level of the B ₁ signal obtained by correcting the deviation of the pixel (correcting B ₁₎ is, B included the signal levels of the B ₁ signal, a pixel adjacent to the B ₁ signal (pixel after 1 cycle of the pixel) (B ₂ ) signal.

Returning to FIG. 1, the description will be continued. Adder 13
Is to generate a new digital video signal having a signal level magnitude obtained by adding the signal levels of the two digital video signals input to the adder 13. This adder 13 can be realized by a general adder circuit.

The gamma correction unit 14 corrects the digital video signal input to the gamma correction unit 14 according to the gamma characteristic of the display. This gamma correction unit 14
Generates a digital video signal having a corrected signal level in accordance with a gamma characteristic in which the signal level of the digital video signal is not proportional to the display brightness of the display.

The operation of the video signal correction circuit 1 will be described below with reference to FIG. First, the digital video signal is input to the R signal correction means 2, the G signal phase delay means 3 and the B signal correction means 4 as R, G and B signals, respectively. The R signal which is the digital video signal input to the video signal correction circuit 1 is corrected by the inverse gamma correction unit 10a in the R signal correction unit 2 according to the inverse characteristic of the gamma characteristic of the display, and is delayed by the delay unit 11a. The phase of the pixel period is delayed. The delayed R signal is input to the multiplication unit 12a at the timing when the new R signal is input to the R signal correction unit 2, and the signal level is 1/3.
And is input to the adder 13a. On the other hand, the newly input R signal is the same as the above, and the inverse gamma correction unit 1
At 0a, it is corrected by the inverse characteristic of the gamma characteristic of the display and input to the multiplication unit 12b. The R signal input to the multiplication unit 12b is reduced in signal level to 2/3 and input to the addition unit 13a. The R signal output from the multiplication unit 12a is an R signal included in a pixel (pixel one cycle before) adjacent to the R signal output from the multiplication unit 12b.

Then, the two input signals whose signal levels have been converted (reduced) by the multipliers 12a and 12b are added by the adder 13a, and then added to 1 by the delayer 11b.
The phase of the pixel period is delayed and output as a corrected R signal corrected by the gamma correction unit 14a according to the gamma characteristic of the display. The operation of the R signal correction means 2 corresponds to the first signal correction step described in the claims.

The G signal, which is a digital video signal input to the video signal correction circuit 1, is a G signal phase delay means 3
The inverse gamma correction unit 10b therein corrects the inverse gamma characteristic of the display, and the delay unit 11c delays the phase of one pixel period. The delayed G signal is output by the gamma correction unit 14b as a corrected G signal corrected according to the gamma characteristic of the display. The operation of the G signal phase delay means 3 corresponds to the phase delay step described in the claims.

Further, the B signal which is the digital video signal input to the video signal correction circuit 1 is corrected by the inverse gamma correction unit 10c in the B signal correction unit 4 according to the inverse characteristic of the gamma characteristic of the display, and the delay unit. The phase of one pixel is delayed by 11d. The delayed B signal is input to the multiplication unit 12c at the timing when the new B signal is input to the B signal correction unit 4, the signal level is reduced to ⅔, and the addition unit 13b is input. On the other hand, the newly input B signal is corrected by the inverse gamma correction unit 10c by the inverse characteristic of the gamma characteristic of the display in the same manner as described above, and is input to the multiplication unit 12d. The signal level of the B signal input to the multiplication unit 12d is reduced to 1/3 and input to the addition unit 13b. This multiplication unit 12d
The B signal output from is a B signal included in a pixel (pixel after one cycle) adjacent to the B signal output from the multiplication unit 12c.

The two input signals whose signal levels have been converted (reduced) by the multipliers 12c and 12d are added by the adder 13b. The added B signal is output by the gamma correction unit 14c as a corrected B signal corrected according to the gamma characteristic of the display. The operation of the B signal correction means 4 corresponds to the second signal correction step described in the claims.

Digital image corrected by the above operation
A specific example of the image signal will be described with reference to FIGS. 1 and 3.
FIG. 3 shows a digital image input to the image signal correction circuit 1.
The signal level of the signal (Fig. 3 (a)) and the corrected output
The digital video signal level (Fig. 3 (b))
It represents. In FIG. 3 (a), R₁, G₁And B ₁
Etc. represent the signal levels of the R, G and B signals, respectively.
And R₁, G₁And B₁Is the signal level of the same gradation
It is assumed that it has a “white” color. Also,
R₂, G₂And B₂Are all minimum gradation signal levels,
Displays the "black" color, R₃, G₃And B₃Is the same tone
No. level and display "white" color.
In addition, in FIG. 3B, R ′₁, G '₁And B '₁Etc.
R in FIG. 3 (a)₁, G₁And B₁Corresponding to the signal corrected
is doing.

For example, the R signal having the signal level of R ₂ is supplied to the pixel (R ₂
Signal level R of the R signal which is the pixel adjacent to the R signal of
₁ is reduced to 1/3, and the signal level R ₂ of the R signal of the current cycle
Are reduced to 2/3, and each is added to output a corrected R signal having a new signal level R ′ ₂ . The corrected R signal having the signal level of R ′ ₂ is the input R signal.
_The R signal having a signal level of ₂ is output after being delayed by one cycle.

[0055] Further, the G signal having a signal level of G ₂ is, by the G signal phase delay means 3, at the same signal level as the signal level of _{G 2 (G '2 = G} 2), having a signal level of G ₂ A delayed G signal delayed by one cycle from the G signal is output.

Further, the B signal having the signal level of B _{2 is} processed by the B signal correction means 4 to the pixel (B ₂
Signal level B of the B signal which is the pixel adjacent to the B signal)
₃ is reduced to 1/3, and the signal level B ₂ of the original period B signal is reduced.
Are reduced to 2/3, and each is added to output a corrected B signal having a new signal level B ′ ₂ . The correction B signal having a signal level of the B _'2 was input B
_The B signal having a signal level of ₂ is output after being delayed by one cycle. In this way, by generating the signal level by interpolating the signal level of the pixel by interpolation, it is possible to suppress a rapid change in the signal level and reduce color fringing.

The present invention has been described above based on the embodiment, but the present invention is not limited to this. For example, when the arrangement of the R, G, and B signals in the unit pixel is not in the RBG order as in this embodiment, that is, the arrangement of the primary color signals in the unit pixel is the first, second, and third primary color signals (first , The second and third primary color signals are R, G and B
Signal combination), the R signal correction means 2 is used as the first primary color signal correction means, the G signal phase delay means 3 is used as the second primary color phase delay means, and the B signal correction means 4 is used as the second signal correction means. , RBG can also be realized by a configuration in which the order of RBGs is changed.

If the digital video signal input to the video signal correction circuit 1 is a signal that has not been gamma-corrected for the display, the video signal correction circuit 1 reverses the gamma correction unit 10 (10a, 10b and 10c). May be deleted or may have a configuration that does not function. Further, when a display or the like connected to the output side of the video signal correction circuit 1 performs gamma correction, the inverse gamma correction unit 14 (14a, 14b and 14c) is deleted from the video signal correction circuit 1 or has a function. It does not matter even if it is not configured.

Further, the multiplication unit 12 (12a, 12b, 12
c and 12d), the interpolation factors are 1/3 and 2 /
Although the value is fixed to 3, a different value may be used as this value depending on the contrast of the display, or the value may be variably set.

Further, in the present embodiment, the signal level is interpolated to generate a new signal level by interpolating the signal levels of two consecutive pixels, but it is not necessary that the number of pixels is two. Alternatively, it can be realized by 3 pixels or 4 pixels. For example, as shown in FIG. 4, P1 (R ₁ ,
G ₁ , B ₁ ), P2 (R ₂ , G ₂ , B ₂ ), P3 (R ₃ ,
G _3, B _3), in a state in which pixels are consecutive _{P4 (R 4, G 4,} B 4), by interpolation of three pixels shown in FIG. 4 (a),
Correction B ₂ and correction R ₃ can be generated. In this case, the correction B ₂ generates the correction B ₂ the level of each B signal are continuous pixels P1, P2 and P3 by interpolating. The correction R ₃ generates a correction R ₃ the level of each R signals are continuous pixels P2, P3 and P4 by interpolating.

Further, the correction B ₂ and the correction R ₃ can be performed by the interpolation of the four pixels shown in FIG. 4 (b). At this time, the correction B ₂ includes P1, P2, and P3 which are continuous pixels.
And correction by interpolating the level of each B signals P4 B ₂
To generate. Further, the correction R ₃ includes P1 which is a continuous pixel,
The corrected R ₃ is generated by interpolating the levels of the R signals of P2, P3, and P4. As described above, depending on the number of pixels to be interpolated, the continuous pixels used to supplement the R and B signals may be different.

For interpolation of 5 pixels or more, both the pixel input in the period before the pixel to be corrected and the pixel input in the subsequent period are 2 pixels from the pixel to be corrected.
Since the distance is larger than the pixel, the effect is diminished in the present invention in which the influence of the pixel adjacent to the pixel to be corrected is taken into consideration. Further, it is not realistic because the circuit becomes huge and the delay time increases due to the increase of the delay circuit.

The interpolation coefficients shown in FIGS. 4A and 4B are examples, and may be changed according to the contrast of the display. Further, in order to realize FIGS. 4A and 4B as a video signal correction circuit, it is realized by adding a delay unit 11 to the video signal correction circuit 1 and further adding a general subtraction circuit. can do.

(Second Embodiment) Next, a second embodiment of the present invention will be described in detail with reference to FIG. FIG. 5 is a block diagram showing the overall configuration of the video signal correction circuit. In the above-described video signal correction circuit 1 (FIG. 1), when a thin line is displayed on the display, for example, when correction is performed in a state where a line of one pixel as shown in FIG. However, when the signal levels of the R signal and the B signal are changed, the contrast may be lowered and the line may be difficult to see.

The video signal correction circuit 1B receives the digital video signals R, G and B signals and changes the correction level of each signal based on the line width, thereby suppressing the decrease in contrast and , A circuit for generating a corrected R signal, a delayed G signal and a corrected B signal with reduced color fringing.

As shown in FIG. 5, the video signal correction circuit 1B
Adds the line width determination means 5 to the video signal correction circuit 1 (FIG. 1), and the multiplication units 12 (12a, 12b, 12c and 12).
d) The multiplication unit 12B (12Ba, 12Bb, 12Bc) that functions to change the interpolation coefficient based on the control signal.
And 12Bd) are modified to include the R signal correction means 2B and the B signal correction means 4B. Line width determination means 5
Since the configurations other than the multiplication unit 12B (12Ba, 12Bb, 12Bc and 12Bd) are the same as those in FIG. 1, the same reference numerals as those shown in FIG. 1 are given and the description thereof is omitted.

The line width determining means 5 determines the white or black line width from the input R, G and B signals, and based on the line width, the multiplication unit 12B (12Ba, 12Bb, 12).
Bc and 12Bd) are individually changed. This interpolation coefficient is applied to each of the multiplication units 12B (12Ba, 12Bb, 12Bc and 12B) via the control signal.
d) is notified.

The line width determination means 5 receives the input R, G
Based on the B signal and the B signal, the edge part (the part changing from black to white and the part changing from white to black) of the digital video signal is detected, and the thickness of the line is measured. For example,
The unit pixel in which the signal levels of the R, G, and B signals are all minimum (minimum gradation value) is determined to be black, and after the black continues, the signal levels of the R, G, and B signals are all maximum (maximum The unit pixel having the gradation value) is determined to be white, and the number of unit pixels in between is determined to be the black line width. Incidentally. The white line width can be measured by reversing the determination of the maximum and minimum of the signal level.

Multiplier 12B (12Ba, 12Bb, 12)
Bc and 12Bd) convert the signal level of the input digital video signal based on the interpolation coefficient notified from the line width determination means 5 as a control signal. In addition, the multiplication unit 12
The control signals notified to Bb and the multiplication unit 12Bc use the same control signal and the same interpolation coefficient. The control signals notified to the multiplication units 12Ba and 12Bd use the same control signal and the same interpolation coefficient.

A specific example of the digital video signal corrected by the above configuration will be described with reference to FIGS. 6 and 7.
FIG. 6 is an example showing the relationship between the line width and the value of the interpolation coefficient. In FIG. 6, α is a multiplication unit 12Bb and a multiplication unit 12B.
represents the interpolation coefficient notified to c, and β is the multiplication unit 12Ba
And the interpolation coefficient notified to the multiplication unit 12Bd. Further, FIG. 6 shows an example in which the interpolation coefficient is changed in three steps with a line width of 1 pixel, 2 pixels, and 3 pixels or more.

FIG. 7 shows the input signal level of the digital video signal input to the video signal correction circuit 1B and the output signal level of the digital video signal corrected and output. FIG. 7A shows an input signal level (a-1) and an output signal level (a- when the line width is one pixel.
2) is represented. In this case, the interpolation coefficient α of the multiplication units 12Bb and 12Bc is 1 as shown in FIG.
Since the multiplication unit 12Ba and the interpolation coefficient β of the multiplication unit 12Ba are 0, the video signal correction circuit 1B
When the R, G, and B signals are input, the correction R is performed without changing the signal level of the R, G, and B signals for one cycle of the pixel.
The signal, the delayed G signal and the corrected B signal are output.

FIG. 7B shows an input signal level (b-1) and an output signal level (b- when the line width is 2 pixels.
2) is represented. In this case, as shown in FIG. 6, the interpolation coefficient α of the multiplication units 12Bb and 12Bc is 5
/ 6, and β, which is the interpolation coefficient of the multiplication unit 12Ba and the multiplication unit 12Ba, is 1/6. Therefore, the video signal correction circuit 1
When the R, G, and B signals are input to the B, the R signal correction unit 2B reduces the signal level of the R signal two cycles before to 1 /.
The signal reduced to 6 and the signal obtained by reducing the signal level of the R signal one period before to 5/6 are added and output as a corrected R signal. Further, the G signal phase delay means 3 outputs the G signal of one cycle before as a delayed G signal. Furthermore, B
The corrected B signal is obtained by adding the signal obtained by reducing the signal level of the B signal one cycle before to 5/6 by the signal correcting means 4B and the signal obtained by reducing the signal level of the B signal of the original cycle to 1/6. Output as.

FIG. 7C shows the input signal level (c-1) and the output signal level (c when the line width is 3 pixels or more.
-2) is represented. In this case, compared with FIG. 7B, the interpolation coefficients 1/6 and 5/6 are 1 /
The same operation is performed except that it is changed to 3 and 2/3.

As described above, by generating the signal level by interpolating the signal level of the pixel by the interpolation, it is possible to suppress the rapid change of the signal level and reduce the color fringing. Furthermore, by changing the signal level interpolated by interpolation based on the line width, it is possible to suppress the decrease in contrast in the thin line. that's all,
Although the present invention has been described based on the embodiment, the present invention is not limited thereto. For example, the interpolation coefficient shown in FIG. 6 may use a different value according to the contrast of the display, or may be adjustable from the outside.

(Third Embodiment) Next, a third embodiment of the present invention will be described in detail with reference to FIG. FIG. 8 is a block diagram showing the overall configuration of the video signal correction circuit. As shown in FIG. 8, the video signal correction circuit 1C includes an R signal correction means 2C and a G signal correction means 3C.
The B signal correction means 4C and the vertical position determination means 6 are included. The video signal correction circuit 1C inputs the R, G, and B signals that are digital video signals, and corrects and delays each signal based on the vertical position of the digital video signal, thereby causing color fringing. It is a circuit that generates the corrected R signal, corrected G signal, and corrected B signal. The video signal correction circuit 1C is provided with R of the unit pixel,
This is a circuit for reducing color fringing in a display having a mosaic structure (see FIG. 13B) in which the arrangement of G and B signals differs depending on the vertical position of the digital video signal.

The R signal correcting means 2C interpolates the input R signal and the R signal of the pixel one cycle before,
The interpolation R signal of a new signal level is generated.
Since this R signal correction means 2C has a configuration in which only the switching unit 15 is added to the R signal correction means 2B shown in FIG. 5, the configurations other than the switching unit 15 are the same as those shown in FIG. Is attached and the description thereof is omitted. Further, since the G signal correction means 3C and the B signal correction means 4C have the same configuration as the R signal correction means 2C, the description thereof will be omitted.

The switching unit 15 switches whether to delay the input R signal by the delay unit 11 (11b) for one cycle of the pixel output. The switching unit 15 performs switching based on the control signal notified from the vertical position determination means 6.

The vertical position determining means 6 determines the vertical position of the R, G, and B signals currently input from the synchronizing signal of the digital video signal, and determines the R, G, and P of the pixel at the vertical position. Based on the arrangement of B signals, the multiplication unit 1
The individual interpolation coefficients of 2B (12Ba, 12Bb) are changed, and the switching unit 15 is switched. A signal (switching signal) for performing the interpolation coefficient and switching is supplied to the R signal correction means 2C via the control signal.
The multiplication unit 12B (12Ba, 12Bb) and the switching unit 15 in the G signal correction unit 3C and the B signal correction unit 4C are notified.

Here, a specific example of the control signal (interpolation coefficient and switching signal) will be described with reference to FIG. FIG. 9 shows an arrangement (pixel structure) of R, G, and B signals,
It is the figure which matched the said control signal. In FIG. 9, a vertical position H1 on the screen has a structure in which pixels are arranged in the order of RGB, a vertical position H2 has a structure in which pixels are arranged in the order of BRG, and a vertical position H3 indicates a pixel. Are the structures arranged in the order of GBR. The vertical positions (H1, H2, and H3) correspond to the vertical position of the display having the mosaic structure (see FIG. 13B).

Further, the interpolation coefficient α of the R signal shown in FIG.
Is notified to the multiplication unit 12Bb in the R signal correction unit 2C, the interpolation coefficient β of the R signal is notified to the multiplication unit 12Ba in the R signal correction unit 2C, and the switching signal sw of the R signal is switched.
Is notified to the switching unit 15 in the R signal correction means 2C. The “through” of the switching signal sw is caused by the delay unit 11
It means that the input path is switched so as not to cause the delay of b, and “delay” means that the input path is switched so as to generate a delay of one cycle through the delay unit 11b. Further, the interpolation coefficients (α and β) and the switching signal sw of the G signal, and the interpolation coefficients (α and β) and the switching signal sw of the B signal are also the G signal correction means 3C and the B signal correction in the same manner as the R signal. The multiplication unit 12B (12B in the means 4C
a, 12Bb) and the switching unit 15 are notified.

For example, when the vertical position detected by the vertical position determining means 6 is the first line of the display (H1), the interpolation coefficient α notified to the multiplication unit 12Bb.
Is “2/3”, and the interpolation coefficient β notified to the multiplication unit 12Ba is “1/3”. Further, the switching signal sw notified to the switching unit 15 becomes “delay”.

As a result, the video signal correction circuit 1C is
In the display of the mosaic structure in which the arrangement of the R, G and B signals of the unit pixel is different depending on the position in the vertical direction,
It becomes possible to control the correction and delay of the R, G and B signals for each position in the vertical direction.

The present invention has been described above based on the embodiment, but the present invention is not limited to this. For example, the line width determination means 5 shown in FIG. 5 is added to the vertical position determination means 6 of the video signal correction circuit 1C, and the interpolation coefficient and the switching signal are changed based on the vertical position and line width. It doesn't matter.

With this configuration, even in a mosaic structure display, a signal level obtained by interpolating the signal level of a pixel by interpolation can be generated, so that a rapid change in the signal level can be suppressed and color blurring can be suppressed. Can be reduced. Furthermore, by changing the signal level interpolated by interpolation based on the line width, it is possible to suppress the decrease in contrast in the thin line.

(Evaluation of Improvement of Color Bleed) Next, the evaluation result of the video signal correction circuit 1 (FIG. 1) in the present invention will be described with reference to FIGS. 10, 11 and 12. FIG. 10 shows a digital video signal which is an image pattern in which a black line is displayed on a white background, and the signal levels of the R, G and B signals are set to a maximum level of "1.0" and a minimum level. It is shown as "0.0". FIG. 10A shows a signal level when the correction according to the present invention is not performed, and FIG.
The signal level when the correction according to the present invention is performed is shown.

When a person recognizes this digital video signal, human vision has a high frequency characteristic (high sensitivity) for the luminance component, but a low frequency characteristic (sensitivity) for the color difference component. Is low). This is considered to be equivalent to applying a low pass filter (LPF) which is digital signal processing.

Therefore, the low-pass filter of FIG. 11 is applied to the digital video signals of FIGS. 10 (a) and 10 (b),
FIG. 12 shows the result of evaluation based on the amount representing the color component of the output (color component = (maximum value among RGB values of LPF output) − (minimum value among RGB values of LPF output)).
Shown in. FIG. 12A shows the signal level of the color component when the correction according to the present invention is not performed, and FIG.
Represents the signal level of the color component when the correction according to the present invention is performed. As shown in FIG. 12A, there is about 1/3 of the color fringing (color shift) that humans perceive visually.
It has been reduced to some extent.

[0088]

As described above, the video signal correction circuit and the video signal correction method according to the present invention have the following excellent effects.

According to the first, third and sixth aspects of the present invention, the video signal correction circuit or the video signal correction method is a color generated when a digital video signal is displayed on a display having a pixel structure. Bleeding can be reduced. This makes it possible to provide an optimum display environment in an environment in which an application that requires an accurate drawing such as CAD operates.

According to the second, fifth, seventh and ninth aspects of the present invention, the video signal correction circuit or the video signal correction method corrects the signal level of the digital video signal according to the line width. Since the amount can be changed, it is possible to prevent the contrast of thin lines from being lowered, to make the lines easier to see, and to reduce color fringing.

According to the fourth and eighth aspects of the present invention, the video signal correction circuit or the video signal correction method converts the digital video signal in the mosaic structure display in which the RGB arrangement is different for each vertical position. It is possible to reduce color fringing that occurs during display. This makes it possible to provide an optimum display environment in an environment in which an application that requires an accurate drawing such as CAD operates.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a video signal correction circuit according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining interpolation between pixels in the present invention.

FIG. 3 is a diagram showing an example of correction of a digital video signal in the first embodiment.

FIG. 4 is an explanatory diagram for explaining interpolation of 3 pixels and 4 pixels in the present invention.

FIG. 5 is a block diagram showing an overall configuration of a video signal correction circuit according to a second embodiment of the present invention.

FIG. 6 is a diagram showing the relationship between the line width and the value of an interpolation coefficient in the second embodiment.

FIG. 7 is a diagram showing an example of correction of a digital video signal in the second embodiment.

FIG. 8 is a block diagram showing an overall configuration of a video signal correction circuit according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between a pixel structure, an interpolation coefficient, and a switching signal in the third embodiment.

FIG. 10 is a diagram showing signal levels of an input signal and an output signal used for performing the evaluation of the present invention.

FIG. 11 is a diagram showing the shape of a low-pass filter used for evaluating the present invention.

FIG. 12 is a diagram showing a signal level after passing through a low-pass filter.

FIG. 13 is an explanatory diagram illustrating a structure of a pixel structure display.

FIG. 14 is an explanatory diagram for explaining color fringing.

[Explanation of symbols] 1, 1B, 1C ... Video signal correction circuit 2, 2B, 2C ... R signal correction means 3 ... G signal phase delay means 3C ... G signal phase correction means 4, 4B, 4C ... B signal correcting means 5: Line width determination means 6 ... Vertical position determination means

Continued front page    F-term (reference) 5C060 BC01 DA02 EA08 HB09 JA20                       JA24                 5C066 CA09 CA17 EC01 EC12 GA01                       GA26 GA33 KD06 KE02 KM13                 5C082 AA01 BA12 CA12 CA22 CA85                       DA51 MM10

Claims (9)

[Claims] 1. A digital video signal, which is input in time series with first, second, and third primary color signals that are the three primary colors of colors as unit pixels, is corrected for each unit pixel in the horizontal direction, A video signal correction circuit for reducing color fringing in a pixel structure display having a pixel structure in which unit pixels are arranged, the signal being a first primary color signal arranged at one end of a correction target pixel to be corrected by the unit pixel. First signal correction means for correcting the level based on a signal level of a primary color signal of the same color as the first primary color signal in a first adjacent pixel which is a unit pixel adjacent to the first primary color signal; The signal level of the second primary color signal arranged at the other end of the pixel is set to the signal level of the primary color signal of the same color as the second primary color signal in the second adjacent pixel which is a unit pixel adjacent to the second primary color signal. A second signal correcting means for correcting the phase of each of the first primary color signal corrected by the first signal correcting means and the second primary color signal corrected by the second signal correcting means. On the other hand, the third pixel in the correction target pixel
A video signal correction circuit comprising: a phase delay means for delaying and synchronizing the phase of a primary color signal. 2. A line width determination means for determining whether a unit pixel is white or black based on the signal levels of the first, second and third primary color signals and determining the line width of the white or black. 2. The video according to claim 1, wherein the first and second signal correction means adjust the correction amount of the signal level based on the line width determined by the line width determination means. Signal correction circuit. 3. A digital video signal input in time series using R, G and B signals which are the three primary colors of color as unit pixels,
A video signal correction circuit that reduces color fringing in a pixel structure display having a pixel structure in which the unit pixels are arranged by correcting each unit pixel in the horizontal direction, and is a correction target of the correction of the unit pixels. R signal correction means for correcting the signal level of the R signal of the target pixel based on the signal level of the R signal in the first adjacent pixel which is a unit pixel adjacent to the R signal; B signal correction means for correcting the signal level based on the signal level of the B signal in the second adjacent pixel which is a unit pixel adjacent to the B signal, and the R signal and the B signal corrected by the R signal correction means. G signal phase delay means for delaying and synchronizing the phase of the G signal in the pixel to be corrected with respect to each phase of the B signal corrected by the signal correction means, A video signal correction circuit characterized by being provided. 4. A digital video signal, which is input in time series with first, second and third primary color signals which are the three primary colors of color as unit pixels, is corrected for each unit pixel in the horizontal direction, A video signal correction circuit for reducing color fringing in a pixel structure display having a pixel structure in which unit pixels are arranged, the vertical position determining a vertical position of the unit pixel based on a synchronization signal of the digital video signal. Determination means, and for each of the first, second, and third primary color signals, the signal level of the primary color signal in the correction target pixel that is the target of correction of the unit pixel is input one cycle before the correction target pixel. A signal correcting means for correcting the primary color signal of the unit pixel based on a signal level of the same color as the primary color signal, and a phase delay means for delaying the phase of the primary color signal corrected by the signal correcting means. Switching means for switching whether to delay the primary color signal corrected by the signal correction means by the phase delay means, and based on the vertical position of the unit pixel determined by the vertical position determination means, A video signal correction circuit, wherein the signal correction means adjusts a correction amount of a signal level and switches the switching means. 5. A line width determination means for determining whether a unit pixel is white or black based on the signal levels of the first, second and third primary color signals and determining the line width of the white or black. The video signal correction circuit according to claim 4, wherein the signal correction means adjusts the correction amount of the signal level based on the line width determined by the line width determination means. 6. A digital video signal input in time series using first, second and third primary color signals which are the three primary colors of color as a unit pixel is corrected in the horizontal direction for each unit pixel, A video signal correction method for reducing color fringing in a pixel structure display having a pixel structure in which unit pixels are arranged, wherein 2 to 4 units are arranged in a horizontal direction and include correction target pixels to be corrected by the unit pixels. A first continuous pixel pixel that corrects the signal level of the first primary color signal of the correction target pixel based on the signal level of the same color as the first primary color signal arranged at one end of the correction target pixel in the first continuous pixel;
Signal correction step of the second primary color signal arranged at the other end of the correction target pixel in the second continuous pixel composed of two to four unit pixels continuous in the horizontal direction including the correction target pixel. A second signal correction step of correcting the signal level of the second primary color signal of the pixel to be corrected based on the signal level; a first primary color signal and the second signal corrected in the first signal correction step; And a phase delay step of delaying and synchronizing the phase of the third primary color signal in the pixel to be corrected with respect to each phase of the second primary color signal corrected in the correction step. . 7. The first and second signal correction steps adjust the correction amount of the signal level based on the line width determined by the line width determination means for determining the line width of a white or black line. The video signal correction method according to claim 6, further comprising an adjusting step. 8. A digital video signal input in time series using first, second and third primary color signals which are the three primary colors of color as a unit pixel is corrected for each unit pixel in the horizontal direction, A video signal correction method for reducing color fringing in a pixel structure display having a pixel structure in which unit pixels are arranged, the correction being a correction target of the unit pixel for each of the first, second and third primary color signals. A signal level of the same color as the primary color signal in the correction target pixel in a continuous pixel including two to four unit pixels continuous in the horizontal direction including the target pixel, and a vertical position for determining the vertical position of the correction target pixel. A signal correction step of correcting the signal level of the primary color signal of the correction target pixel based on the position in the vertical direction determined by the determination means, and based on the position in the vertical direction And a phase delay step of delaying the phase of the primary color signal corrected by the signal correction step, and a video signal correction method. 9. The signal correction step includes an adjustment step of adjusting the correction amount of the signal level based on the line width determined by the line width determination means for determining the line width of a white or black line. 9. The method according to claim 8, wherein
The video signal correction method described in.