JPS623295A - Display image compensation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a display device having a plurality of pixels arranged regularly in the horizontal and vertical directions: - A display image that smoothly displays an image. Regarding compensation methods.

[Conventional technology]

BACKGROUND ART In raster scanning cathode ray tube displays, liquid crystal displays, plasma displays, and other flat displays used in display devices, a plurality of pixels are regularly arranged in the horizontal and vertical directions. In addition, each memory location of the memory circuit (display memory) that stores display images has a one-to-one correspondence with each pixel of the display device, so the display device Display is performed by modulating the brightness of the corresponding pixels. By the way, in these display devices, the total number of pixels is limited to, for example, 1280x1024 due to limitations on the resolution of the display and the storage capacity of the storage circuit. Therefore, the ideal display position calculated by a vector generator or the like and the actual display position deviate from each other, and the oblique image is displayed in a jagged manner. This is generally called jaggies.

In order to improve this jaggies, several proposals have been made in the past. Among these, the first prior art is based on the calculation of a calculated display position and two pixels that sandwich this display position, as disclosed in Japanese Patent Application Laid-open No. 55-95986 and Japanese Patent Application Laid-Open No. 56-156873. The brightness of these two pixels is modulated depending on the distance. The second conventional technology is
As disclosed in Japanese Patent No. 8-37685, a sub-deflection circuit is provided in the cathode-ray tube in addition to the main deflection circuit to bring the bright spot on the cathode-ray tube close to the calculated display position. Japanese Patent Publication No. 59-9
A third conventional technique disclosed in Japanese Patent No. 9486 is that when reading out the storage contents from an image storage circuit in synchronization with rask scanning and generating a brightness control signal, the readout signal from the storage circuit is divided into 1/2 pixels. The luminance control signal is obtained by combining the delayed signal and the non-delayed signal. Also, JP-A-60
In the fourth prior art disclosed in Japanese Patent No. 2987, the display performs inkless display, and the image storage circuit is divided into a color data area and a light emission control data area corresponding to this area. Then, the memory contents of these areas are simultaneously read out, and color data is selectively supplied to the display in fields 1 and 2 according to the light emission control data. At the same time, the color data is selectively delayed in the horizontal direction. Shifting pixels.

[Problem that the invention seeks to solve]

In the above-mentioned first conventional technique, since the brightness is proportionally distributed, the arithmetic processing is complicated, the circuit configuration is complicated, and it is also difficult to apply to curves. Furthermore, the second prior art requires a highly accurate deflection circuit.

The circuit configuration was complicated and expensive. Further
In the prior art '3, the readout signal from the storage circuit is
□Delay can only shift the pixels of the display in the horizontal direction, so if the slope of the straight line is 45 degrees or more with respect to the horizontal
In the case of □, the jaggies could not be improved. Further, in the fourth conventional technique, an extra storage capacity of the image storage circuit is required.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a display image compensation method for improving jaggies in images of line drawings such as straight lines and curved lines and area drawings with a simple hardware configuration.

[Failure to solve the problem]

In the image compensation method of the present invention, when reading the luminance value of an image written in a memory circuit having memory locations corresponding to a plurality of pixels regularly arranged in the horizontal and vertical directions and displaying it on a display device, , the first process of sequentially calculating the sum of the luminance values of vertically adjacent pixels and writing a new luminance value corresponding to this sum into the memory location of the upper pixel, and the luminance of vertically adjacent pixels. A second process of sequentially calculating the sum of the values and writing a new brightness value corresponding to this sum into the memory location of the lower pixel, and a second process of sequentially calculating the sum of the brightness values of horizontally adjacent pixels and writing this sum. A third step is to write a new brightness value corresponding to the left pixel into the storage location of the pixel on the left, and the sum of the brightness values of horizontally adjacent pixels is sequentially calculated, and a new brightness value corresponding to this sum is written to the memory location of the pixel on the right side. The fourth step of writing data into the storage location of the pixel is performed in a predetermined order, and the new brightness value is read out from the storage circuit to smoothly display the image on the display.

[Effect]

In the present invention, since the image is compensated as described above,
“When looking at a single pixel, the brightness of that pixel itself can be made the highest, the brightness of the four pixels on the top, bottom, left and right of that pixel can be lowered, and the brightness of the four pixels in the diagonal direction can be further lowered, and the overall brightness can be lowered. □Can display images as natural and smooth as possible.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, the present invention will be explained in detail. FIG. 2 shows the brightness values of nine pixels. in this case,
The brightness value of the center pixel is set to 4, the brightness values of the four pixels above, below, left and right of the center pixel are set to 2, and the brightness values of the four pixels in diagonal directions from the center pixel are set to 1. Then, one point becomes 9
It is expressed as the sum of 7 brightness values of each pixel, resulting in a smooth image as a whole. Next, a method for creating the image shown in FIG. 2 will be explained according to the flowchart shown in FIG. 1'. First, a brightness value of 1 is given only to pixel 1, element 4 in FIG. 3, and brightness values of all other pixels are set to O. (The circles in Figures 2 and 3 represent each pixel, but please note that the numbers inside the circles represent the brightness value in Figure 2 and the pixel number in Figure 3.) It is assumed that pixels with a luminance value of 0 are arranged around the nine pixels. First, in a first process (step 1), the sum of the brightness values of vertically adjacent pixels is determined, and this sum is set as the new brightness value of the upper pixel.

For example, the sum of the brightness value 0 of pixel 1 and the brightness value 1 of pixel 4 is 1
Let be the new luminance value of pixel 1. If this process is performed for each pixel, the result will be as follows.

Next, in a second process (step 2), the sum of the luminance values of vertically adjacent pixels is determined, and this sum is set as the new luminance value of the lower pixel. For example, the sum 2 of the brightness value 1 of pixel 1 and the brightness value 1 of pixel 4 is set as the new brightness value of pixel 4. If this process is performed for each pixel, the result will be as follows.

Furthermore, in the third process (step 3), the sum of the luminance values of pixels adjacent in the horizontal □ direction is calculated, and this sum is .

Let be the new brightness value of the left pixel. For example, the sum 2 of the brightness value O of pixel 3 and the brightness value 2 of pixel 4 is set as the new brightness value of pixel 3. If this process is performed for each pixel, the result will be as follows.

Furthermore, in the fourth process (step 4), the sum of the luminance values of horizontally adjacent pixels is determined, and this sum is set as the new luminance value of the pixel on the right side. For example, the sum of the brightness value 2 of pixel 3 and the brightness value 2 of pixel 4, 4, is set as the new brightness of pixel 4. If this process is performed for each pixel, the result will be as follows.

This result is the same as the luminance value of each pixel shown in FIG. Moreover, even if the first to fourth superimpressions are performed in any order, the result will be the same.

Generally, the brightness value of each pixel of the display is stored in a storage location of the storage device that corresponds to each pixel. In the example above, the highest brightness value is 4, so each storage location is 2 bits. By the way, in the first process, the result of the operation (sum) is written to the memory location of the upper pixel, so
If the calculation order is performed from the upper pixel to the lower pixel, no separate storage circuit is required. Similarly, if the calculation is performed from the bottom to the top in the second process, from the left to the right in the third process, and from the right to the left in the fourth process, no separate storage circuit is required.

FIG. 4 is a block diagram of an example of a display device that utilizes the present invention. Input device 10 such as a tablet or keyboard
Image information from a host computer (not shown) is supplied to a vector generator 14 via a central processing unit (CPU) 12. The CPU 12 can be, for example, a microprocessor, and the vector generator 14 can be, for example, a digital differential analyzer (DDA). Vector generator 14 writes the generated vectors into display memory (bit manop memory) 16. The positions of each brightness stored in the display memory 16 are not ideal display positions and therefore include jaggies. Therefore, the CPU 12 compensates the brightness value of each pixel in the display memory 16 according to the program stored in the ROM 18 and corresponding to the flowchart in FIG. It is read out and displayed on the display 22.Since these configurations are well known, further detailed explanation will be omitted.'Figure 5 shows the 10x
IO pixels are shown. This is display memory 16 and display 2
Corresponds to 2. The luminance value written by the vector generator 14 is written to the pixel P. . So i. . .

:Pixel P. , then i. 1...Pixel P [1 at +9
When it is assumed to be 0°,... When the image compensation according to the present invention is performed, for example, the final brightness value I11 of the pixel pH is as follows OL+ = joo +2 ioI+fo
z+2 i+o +4 i+++2 i, + t2o
+2 i2. + i2゜Other inner pixels also have pixel pH
results in the same result.

Regarding surrounding pixels, the luminance value of the external pixels may be set to 0, for example, pixels P0° and P. Final brightness value of 1. . and engineering. I becomes as follows.

Ioo = joo + lot + i+o + i
, IIn+ = ioo +21ol + 1o2+lt
o +zt,, +112 Note that the numbers inside the circles indicate the brightness values. By performing the same process as above, the first
After executing the process, it will look like Figure 7, after executing the second process, it will look like Figure 8, after executing the third process, it will look like Figure 9, and after executing the fourth process, it will look like Figure 10. become that way. In this example, the highest final brightness value is 8, so each storage location in display memory 16 requires three pits, or three memory planes. When the image is displayed on the display 22 using these final brightness values, it will look like the one shown in FIG. 11, and it can be seen that it is a smooth diagonal line without jaggies.

Although the above is a description of the preferred embodiment of the invention,
Various modifications and changes can be made without departing from the spirit of the invention. For example, the brightness value written by the vector generator may be any value other than 1, and if the number of bits in each storage location is limited, the lower bits of the calculated sum may be discarded.

〔Effect of the invention〕

As described above, according to the present invention, no special storage circuit or the like is required, and the hardware becomes simple. Further, since the calculation is only a simple sum, the calculation is easy.

Furthermore, the present invention merely mechanically performs calculations on each memory location in the memory circuit, and there is no need to newly obtain each vector, and any image, regardless of whether it is a straight line or a curve, can be displayed smoothly.

[Brief explanation of drawings]

FIG. 1 is a flowchart for explaining the present invention, FIGS. 2 and 3 are diagrams showing pixels for explaining the present invention in detail, FIG. 4 is a block diagram of a display device using the present invention, and FIG. 5 6 to 10 are diagrams showing luminance values of each pixel for explaining the present invention, and FIG. 11 is a diagram showing a display according to the present invention. Patent applicant Sony Tektronix Corporation ■■■ Notebook 2 diagrams ■■■ 3rd issue Figure 4 and 1A5 diagram ゛゛■■■■■■■■■■■ ■■■■■■■■■■■ ■ ■■■■■■■■■■ 70th ■■■■■■■■■■■ □ ■■■■■■■■■■■ O・・・・・・・O・■ 811 area

Claims (1)

[Claims] In a method for reading the luminance value of an image written in a memory circuit having memory locations corresponding to a plurality of pixels regularly arranged in the horizontal and vertical directions and displaying the same on a display device, the pixels adjacent to each other in the vertical direction A first process of sequentially calculating the sum of the brightness values of the two pixels and writing a new brightness value corresponding to the sum into the storage location of the upper pixel, and calculating the sum of the brightness values of the vertically adjacent pixels. A second process of sequentially calculating the sum of the brightness values of the pixels adjacent to each other in the horizontal direction and writing a new brightness value corresponding to this sum into the storage location of the pixel on the lower side; A third process of writing a new brightness value corresponding to the above into the storage location of the pixel on the left, and sequentially calculating the sum of the brightness values of the horizontally adjacent pixels, and writing a new brightness value according to this sum. A fourth step of writing into the memory location of the pixel on the right side is performed in a predetermined order, the new luminance value is read from the memory circuit, and the image is smoothly displayed on the display. Image compensation method.