JPH1078772A - High picture quality screen display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a display screen having high picture quality by suppressing sudden change of gradation between a front scene object part and a pixel adjacent to it. SOLUTION: This device is provided with a difference detecting section 35 in which a front scene signal supplied from a CPU 31 is temporarily stored, a buffer resistor 34 as the front screen signal and a stored front screen signal are compared with a front scene signal, when both signals are different each other, a difference front scene signal is outputted. A contour part of a front scene object is detected by variation of the front scene signal, and it is made intermediate gradation. Thereby, gradation variation between the contour part and pixels being adjacent it is reduced, and screen display in which ruggedness of the contour part of the front scene object is not remarkable and which is easy to watch is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device used for an information processing device such as a personal computer or a word processor for drawing a line image or a character on a background image. The present invention relates to a high-quality screen display device that realizes a high-quality display screen.

[0002]

2. Description of the Related Art Conventionally, in an information processing apparatus such as a personal computer or a word processor, a screen display is realized by a configuration as shown in FIG. In FIG. 4, reference numeral 11 denotes a CPU, which sends a foreground signal to the calculation unit 14 and controls the entire movement. Reference numeral 12 denotes a bus. All data flows from the CPU 11 to the CPU 11 are performed via the bus 12. Normally, a main storage device and the like are also connected to the bus 12, but are not shown here. Reference numeral 13 denotes a color register, and the CPU 11 writes a foreground color value into the color register 13. The written value is output to the arithmetic unit 14 as a foreground color signal.

[0003] Reference numeral 14 denotes an arithmetic unit, which outputs the foreground signal to the screen storage unit 15 as a new background signal when the foreground signal represents a line portion of a line drawing / character. Reference numeral 15 denotes a screen storage unit which stores background signals for at least one screen and sequentially sends them to the display unit 16. When the new background signal is input, the value of the background signal is rewritten accordingly. Reference numeral 16 denotes a display unit which displays background signals sequentially sent from the screen storage unit 15 on the screen.

FIG. 5 shows an example of a signal of each section in the prior art. The CPU 11 is connected to the arithmetic unit 14 through the bus 12
For example, a foreground signal as shown in FIG. Since then
A line such as a character shown here is called a foreground object. The arithmetic unit 14 paints only the portion where the foreground object exists with the color specified by the color register 13.
Here, it is assumed that “black” is designated as the color register 13 as an example. When the background signal stored in the screen storage unit 15 is, for example, as shown in FIG.
Is output as shown in FIG. 5 (c).
Thus, the background signal is updated as shown in FIG.
Output to the display unit 16.

[0005]

FIG. 5 (c)
When attention is paid to the outline of the foreground object in the new background signal shown in FIG. 7, it can be seen that the luminance sharply changes from white to black between adjacent pixels. This is because when the foreground signal indicates a foreground object, a new background signal is simply generated from the foreground signal.

Conventionally, the background signal in the screen storage unit 15 has been updated with such a new background signal. For this reason, when viewed on the screen of the display unit 16, there is a problem that the jaggedness is conspicuous at the outline of the oblique line as indicated by reference numeral 21 in FIG. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described points, and suppresses a rapid change in gradation between a foreground object portion and a pixel adjacent thereto, thereby realizing a high-quality display screen. It is an object to provide a display device.

[0008]

SUMMARY OF THE INVENTION The present invention is a high-quality screen display apparatus for drawing a line drawing or a character on a background image, and foreground signal supplying means for supplying a foreground signal indicating a line portion of the line drawing / character. Temporary storage means for temporarily storing the foreground signal supplied by the foreground signal supply means, and outputting the foreground signal as a stored foreground signal; and supplying the foreground signal and the foreground signal output from the temporary storage means. Comparing the foreground signal supplied by the means, a difference detection means for outputting a difference foreground signal when both are different, and a foreground signal storage means for storing the color of a line drawing or a character and outputting it as a foreground signal The foreground signal output from the foreground signal storage means is input, and when the difference foreground signal is output from the difference detection means, the luminances of the foreground signal and the background signal are averaged. Computing means for outputting an intermediate color signal having the calculated value as a new background signal, not outputting the difference background signal, and outputting the foreground signal as a new background signal when the foreground signal indicates a foreground object; Image storage means for storing a background signal, updating the background signal based on the new background signal output from the arithmetic means, and outputting the updated background signal, displaying the background signal output from the image storage means It is characterized by doing.

According to such a configuration, the contour portion of the foreground object is detected by the change of the foreground signal, and the gradation is changed to an intermediate gradation, so that the gradation change between the contour portion and the pixel adjacent thereto is reduced. Can be done. As a result, it is possible to realize an easy-to-view screen display in which the jagged edges are not noticeable even at the outline portion of the foreground object.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a high-quality screen display device according to an embodiment of the present invention. This device is a display device that draws a line drawing or a character on a background image, and includes a CPU 31, a bus 32, a color register 33,
Buffer register 34, difference detection unit 35, calculation unit 36,
It has a screen storage unit 37 and a display unit 38.

The CPU 31 generates a foreground signal indicating a line portion of a line drawing / character. Further, a foreground color signal is written in the color register 33. This CPU 31 implements the foreground signal supply means of claim 1.

The bus 32 is a digital signal transmission path for connecting the CPU 31 to other devices. The foreground signal and the foreground signal are sent from the CPU 31 through the bus 32 to the arithmetic unit 36.
And the color register 33 respectively.

The color register 33 stores the color of a line drawing or a character. The color register 33 holds the foreground color signal written by the CPU 31 and outputs the signal to the arithmetic unit 36. This color register 33 realizes the foreground color signal storage means of the first aspect.

The buffer register 34 stores the CPU 3
The foreground signal sent from 1 is held and output as a stored foreground signal. This buffer register 34 implements the temporary storage means of claim 1.

The difference detector 35 compares the foreground signal sent from the CPU 31 with the stored foreground signal output from the buffer register 34, and when the two are different, that is, when the foreground signal changes between adjacent pixels, the difference is detected. Generate a foreground signal. This difference detection unit 35 implements the difference detection means of the present invention.

The operation unit 36 receives the foreground color signal output from the color register 33, and when the difference foreground signal is output from the difference detection unit 35, calculates the average value of the luminance of the background signal and the luminance of the foreground color signal. The intermediate color signal is output as a new background signal. When the difference foreground signal is not output and the foreground signal indicates the foreground object, the foreground signal is output as a new background signal. Nothing is output otherwise. The calculation section 36 implements the calculation means of claim 1.

The screen storage section 37 stores an image for one screen, and outputs the stored image as a background signal. When a new background signal is generated, the background signal is updated accordingly. This screen storage unit 37 is provided in
Is realized.

The display section 38 displays an image for one screen (updated background signal) stored in the screen storage section 37 on the screen. Next, a flow of processing when characters are actually displayed will be described with reference to FIG. FIG. 2 is a diagram showing an example of each section signal in the embodiment.

First, the CPU 31 performs a process of writing a foreground color signal to the color register 33 via the bus 32. Here, it is assumed that black characters are drawn. Therefore, the foreground color signal indicates black.

Next, the CPU 31 outputs a foreground signal via the bus 32. Here, a foreground signal as shown in FIG. 2A is used as an example. In this case, the data is scanned and output in the order of upper left → upper right → ... → lower left → lower right. This foreground signal is input to the buffer register 34, the difference detection unit 35, and the calculation unit 36.

The buffer register 34 holds this foreground signal until the next foreground signal comes, and outputs this as a stored foreground signal. As a result, the stored foreground signal is as shown in FIG.
As shown in the figure, the signal is always the foreground signal of the pixel one pixel left of the foreground signal. The difference detection unit 35 compares the foreground signal with the stored foreground signal, and outputs a difference foreground signal as shown in FIG. 2C when the two are different, that is, when the foreground signal changes between adjacent pixels. I do.

The difference foreground signal generated in this way is supplied to the calculation unit 36. As a result, in the arithmetic unit 36,
When the differential foreground signal is output, an intermediate value between the background signal and the foreground signal (here, a value obtained by simply averaging the two signals and rounding down the fraction) is output as a new background signal. If no differential foreground signal is output and the foreground signal indicates a foreground object, the calculation unit 36 outputs the foreground signal as a new background signal as it is. If none of the above applies, nothing is output. When the background signal is as shown in FIG. 2D, the new background signal is as shown in FIG.

Here, the screen storage section 37 stores an image for one screen and outputs this as a background signal. When a new background signal is output from the arithmetic section 36, the new background signal is output. And updates the background signal based on the background signal.
The display unit 38 displays the background signal output from the screen storage unit 37 on the screen. As a result, the display contents are as shown in FIG.
(F).

Thus, the current foreground signal and its 1
By generating a difference foreground signal from the immediately preceding foreground signal and outputting, as a new background signal, an intermediate color signal having a value obtained by averaging the luminance of the foreground signal and the background signal based on the difference foreground signal, An intermediate color between the background signal and the foreground color signal is displayed at the outline. As a result, on the screen of the display unit 16, the jaggedness of the line is not conspicuous even with the contour of the oblique line as indicated by reference numeral 41 in FIG.

The above description is for the case where the image is monochrome, and corresponds to claim 1 of the present invention. In the case of color,
The processing described above is performed on each of the three primary colors (or YUV) of R (red), G (green), and B (blue) in the arithmetic unit 36. Note that YUV is a luminance signal (Y) and a color signal (U, V), and is one of symbols representing colors.
Even in the case of using this YUV signal, it is necessary to finally convert it to an RGB signal in order to display it on a CRT. Therefore, conversion from YUV to processing of the present invention to RGB or conversion from YUV to RGB is performed. → A process such as the process of the present invention is required.

Here, when each of the foreground color signal, the new background signal, and the background signal has three numerical values indicating the three primary colors of the color image, the arithmetic unit 36 calculates the three values of the background signal and the foreground color signal, respectively. The value obtained by averaging the two numerical values is defined as an intermediate color signal. This is claim 2 of the present invention. Other parts are the same as above. Thereby, even in the case of a color image, it is possible to realize an easy-to-view screen display without jagged lines of the outline.

By the way, when the above-mentioned numerical values of the three primary colors are used, data of 8 bits each, that is, a total of 24 bits is required for each pixel. On the other hand, the contents of the screen storage unit 37 do not directly represent the intensity of the luminance or the color.
It may be an index representing a limited color such as any 256 colors out of a million colors. When such an index is used, the value directly represents a color, so that the data amount can be reduced as compared with the case where the numerical values of the three primary colors are used. Claim 3 of the present invention applies the present invention in such a case.

FIG. 3 shows an example of the configuration. In FIG.
Reference numerals 51 to 58 are the same as reference numerals 31 to 38 in FIG. 1, respectively, and thus description thereof will be omitted. The difference is the conversion table indicated by reference numeral 59. The conversion table 59 stores the stored intermediate color signal corresponding to the value of the foreground color signal. This conversion table 59 implements the intermediate color table of claim 3.

In an index image, it is not possible to calculate an intermediate color by an arithmetic operation. This is because the index value is a value that directly indicates a color, and even if the values are averaged, it cannot be an intermediate color. For example, if there is a first color having an index value of “100” and a second color having an index value of “50”, the index value “75” which is the average value is the first color and the second color. Will not be an intermediate color but a completely different color.

Therefore, for each background color, an index value representing an intermediate color (or a color close thereto) with the foreground color signal is stored in the conversion table 59 in advance. A background signal is input to the conversion table 59, and if a difference foreground signal is output, an index value of the color to be converted is always output.

When the differential foreground signal is output, the arithmetic unit 56 outputs the index value (a value indicating an intermediate color) as a new background signal, and the differential foreground signal is not output.
If the foreground signal indicates a foreground object, the foreground signal is output as a new background signal. As a result, even in the case of an index image, an easy-to-see screen display is realized as in other cases.

In addition, as in claim 1 or claim 2,
Even if the image is not an index image, it is possible to perform conversion using a conversion table according to a third aspect. However, as a general tendency, the method using the conversion table is fast, but the amount of hardware is large.

[0033]

As described above, according to the present invention, the contour of the foreground object is detected based on the change of the foreground signal.
Since the gray level is set to an intermediate gray level, it is possible to reduce a gray level change between the contour portion and a pixel adjacent thereto. As a result, it is possible to realize an easy-to-view screen display in which the jagged edges are not noticeable even at the outline portion of the foreground object.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a display device according to an embodiment of the present invention.

FIG. 2 is an exemplary view showing an example of signals of each section in the embodiment.

FIG. 3 is a block diagram showing a configuration of a display device as another embodiment.

FIG. 4 is a block diagram illustrating a configuration of a conventional display device.

FIG. 5 is a diagram showing an example of signals of each section in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 ... CPU 32 ... Bus 33 ... Color register 34 ... Buffer register 35 ... Difference detection unit 36 ... Calculation unit 37 ... Screen storage unit 38 ... Display unit

Claims (3)

[Claims] 1. A high-quality screen display device for drawing a line image or a character on a background image, comprising: a foreground signal supply unit for supplying a foreground signal indicating a line portion of a line drawing / character; Temporary storage means for temporarily storing the supplied foreground signal and outputting it as a stored foreground signal; and the memory signal output from the temporary storage means and the foreground signal supplied by the foreground signal supply means. And a difference detection means for outputting a difference foreground signal when the two are different, a foreground signal storage means for storing the color of a line drawing or a character and outputting it as a foreground signal, The foreground signal to be output is input, and when the difference foreground signal is output from the difference detecting means, an intermediate color signal having a value obtained by averaging the luminance of the foreground signal and the background signal. And output as a new background signal,
When the differential background signal is not output and the foreground signal indicates a foreground object, an operation unit that outputs the foreground signal as a new background signal; and the storage unit stores the background signal and is output from the operation unit. An image storage means for updating and outputting the background signal based on a new background signal, and displaying the background signal output from the image storage means. 2. The foreground color signal, the new background signal, and the background signal each include three numerical values indicating three primary colors of a color image. 2. The high quality image display device according to claim 1, wherein a value obtained by averaging the two numerical values is used as an intermediate color signal. 3. An intermediate color table storing an intermediate color signal corresponding to the value of the foreground color signal, wherein the calculating means outputs the stored intermediate color signal stored in the intermediate color table as a new background signal. 2. The high-quality screen display device according to claim 1, wherein: