WO2006074584A1

WO2006074584A1 - A method for improving the display effect of display device

Info

Publication number: WO2006074584A1
Application number: PCT/CN2005/000972
Authority: WO
Inventors: Hongan Li; Haiyan Zhang; Haiying Li; Sikuan Shen; Minghai Guo; Zhiming Liu; Tiejun Lu; Run Jiang; Qifeng Dai; Zhian Li; Guocheng Kang
Original assignee: Shenzhen Chuangwei-Rgb Electronics Co., Ltd.
Priority date: 2005-01-17
Filing date: 2005-07-04
Publication date: 2006-07-20

Abstract

A method for improving the display effect of display device, which is achieved by selecting one step or combining several or all steps as following: adjusting the display color of the display device; enhancing the dynamic depth of field of input image; enhancing the edge of image and converting the color space according to user’s color preference. The effectiveness of this invention lies in: since the display device is corrected by using six primaries, it can fit human’s visual habit better and can make the abstract non-lineal adjustment more directly and accurately; since specific processing manner is determined dynamically according to the characteristics of each input image, the display image is always maintained to have good performance of depth of field; since the edge enhancement degree is determined according to brightness difference between adjacent pixels by using the classification method, the edge enhancement noise can be eliminated thoroughly and can get definite and sharp image; since it utilizes the method of converting the original color range into object color range accordingly, it can adjust specific color without influence hue and saturation information of other parts of the image and can adjust the image more flexibly and accurately.

Description

Method for improving the display effect of a display device

[Technical Field]

The present invention relates to color image processing techniques, and more particularly to a method of improving the display effect of a display device.

【Background technique】

In recent years, the development of digital TV broadcasting has been very rapid. The developed countries such as the United States, Japan, and Europe have entered the stage of fully implementing the digitalization of television broadcasting. The United States is not only committed to increasing the number of high-definition digital TV programs, but also decided to stop broadcasting simulations in 2006. Television, and cable high-definition digital TVs in many large and medium-sized cities in China have been broadcast, and it is determined that the analog TV will be completely stopped in 2015. Since the transmission of digital television has little damage to the quality of the program, the user can get the signal quality almost equal to the studio at home. However, TV sets currently on the market (especially those using new display devices, such as LCDTV, PDPTV, DLPTV, etc.) cannot be displayed with high quality due to various problems.

Most color display devices display different proportions of red, green, and blue by the additive primary color red, green, and blue display units, and then achieve spatial color mixing by means of the characteristics of the human eye to achieve color image display. That is, the input signals of the display device are red, green, and blue primary color signals. In the past few decades, in order to improve the quality of TV images, the industry has made continuous progress in improving the "three primary colors" imaging and processing technology. In color TV manufacturing enterprises, due to fierce market competition, often the same model needs to match different display screens, but the characteristics of different display screens are different, such as the color reproduction range. Therefore, if the white balance of the factory products is to be consistent, it is necessary to carry out Tuning, sacrificing the color reproduction range of some displays to achieve white balance consistency. All the methods used in the above adjustments have been to adjust the three primary colors of red, green and blue of the display device, usually by adjusting their corresponding gamma correction curves. However, due to the nonlinearity of the photoelectric characteristics of the display device, and the difficulty in visually correlating the three primary color adjustments with the rich color changes of the screen, it is difficult to achieve the accuracy of the color reproduction of the brightness of each level and the overall whiteness. Balancing the problem, the display device can not achieve the desired picture.

In the use of color display devices, when playing some image signals, due to poor shooting conditions or recording special scenes, the picture is often too bright or too dark to distinguish the details of the image, and does not fit the person. Visual habits of the eye. At this time, some TVs allow the user to improve by adjusting the brightness of the display device, but this adjustment is fixed. Once applied, all displayed images will be treated the same, and the TV picture is never fixed. Therefore, it is difficult to achieve the desired effect.

Providing a clear outline of image display has also been pursued for a long time. Image edge enhancement technology has been developed for a long time. Analog circuits generally use 2 differential processing, while digital circuits generally use digital filtering. At present, many TV sets have the functions of "clear", "standard", "soft", etc. in the user-oriented setting interface, and some even set the resolution to hundreds of adjustable. Level, these are actually the choices for edge enhancement Alternatively, after the user makes a selection, the display device performs a unified edge enhancement process on all the input signals according to the set parameters, even if the image is relatively sharp, but often brings obvious hooks. Sound, the effect of glare is rough and it is difficult to achieve the desired clear state. '

In addition, sometimes people tend to make local adjustments to certain specific display colors, such as human skin color, blue sky, green grass, etc., but most existing TV image adjustments only provide overall color change. For example, adjusting the red, green, and blue display components of the entire screen, so that the adjustment is often "to take one shot and move the whole body", unable to meet the requirements for changing the color of a particular preference.

[Summary of the Invention]

The technical problem to be solved by the present invention is to provide a method for improving the display effect of the display device in view of the above-mentioned deficiencies of the prior art. The invention can: adjust and compensate the deviation of the color reproduction of the display device intuitively and effectively; and/or can dynamically adjust the depth of field according to the characteristics of the displayed image; and/or can improve the image clarity and completely eliminate Hook noise; and/or can adjust for a specific color range.

In order to achieve the above object, the technical solution adopted by the present invention is

A method for improving the display effect of a display device, comprising the steps of: adjusting a display color of a display device: dividing each pixel of the input image signal into a corresponding brightness level; and displaying the six primary colors of the display device at different brightness levels Adjusting separately, the six primary colors are composed of three primary colors of red, green and blue and three new primary colors, and the three new primary colors are generated by pairing the three primary colors according to a fixed color matching ratio, when the pair is new When one of the primary colors is adjusted, it is equivalent to simultaneously adjusting the two primary colors corresponding thereto according to the fixed ratio.

Preferably, the three new primary colors are: yellow and green in a ratio of 50% each; yellow and blue are combined according to the ratio of 50% each; cyan and red are in accordance with each A 50% ratio produces a magenta color.

The brightness level can be divided according to the brightness change capability of the display device; generally it can be divided into 64 levels. And, another method for improving the display effect of the display device, comprising the step of: boosting the dynamic depth of field of the input image: firstly, the brightness information of each pixel in the determined range of the input picture is counted, and the brightness information is included in each brightness signal. The number of pixels of the value and the average value of the brightness; if the ratio of the number of pixels in the high luminance signal value to the total number of sampling pixels is greater than the set white level expansion processing start threshold, white level expansion processing is performed such that the ratio Decrease; if the brightness average value is greater than the set black level expansion processing start threshold, perform black level expansion processing such that the brightness average value decreases; if the number of pixels in the low luminance signal value is the total number of pixels sampled If the ratio is greater than the set brightness curve correction processing start threshold 1 or the brightness average value is less than the set brightness curve correction processing start threshold 2, the brightness curve correction processing is performed according to the set correction intensity, so that the ratio is decreased or the brightness average value improve.

The luminance signal value can be divided according to the luminance performance capability of the display device. Preferably,

The high luminance signal value refers to a luminance signal value higher than a set white level extension starting point.

The low luminance signal value refers to a luminance signal value lower than the luminance threshold correction processing start threshold two.

Further preferably,

The luminance signal value is divided into 256 levels, and the white level extension starting point is 128 to 255.

The brightness signal value is divided into 256 levels, and the brightness curve correction processing start threshold 2 is 0~127. And, another method for improving the display effect of the display device, comprising the step of image edge enhancement: first, detecting a luminance difference of adjacent pixels in the input image signal, wherein the luminance difference refers to a luminance signal value of the adjacent pixel The difference is determined according to the set upper and lower limits of each brightness difference area, wherein the area containing the high brightness difference and the low brightness difference corresponds to weak edge strength or no hooking, brightness The area in which the difference is in the middle corresponds to the strong hook strength; and the hook edge processing is performed according to the above-mentioned hook strength value.

Preferably, the brightness difference area is divided into five parts, the lower limit of 0 to the second brightness difference is a low brightness difference area, the lower limit of the second brightness difference to the lower limit of the brightness difference is a low brightness difference transition area, and the lower limit of the brightness difference to the upper limit of the brightness difference In the medium-light difference area, the upper limit of the brightness difference to the upper limit of the second brightness difference is the high-brightness difference transition area, and the upper limit of the brightness difference to the highest brightness signal value is the high-brightness difference area; wherein, the high- and low-light difference areas correspond to the weak-hook edge strength or Without the hooking process, the medium-light difference area corresponds to the strong edge strength, and the high- and low-lightness transition area corresponds to the linear interpolation value of the edge strength used in the adjacent brightness difference area.

More preferably, the value of the lower limit of the brightness difference is 0% to 50% of the value of the highest brightness signal, and the value of the upper limit of the brightness difference is 50% to 100% of the value of the highest brightness signal, and the value of the upper limit of the brightness difference is greater than the lower limit of the brightness difference. Value.

Further preferably, the brightness signal value is divided into 256 levels, the value of the lower limit of the brightness difference can be selected from 0 to 127, and the value of the upper limit of the brightness difference can be selected from 128 to 255.

Further preferably, the brightness signal value is divided into 256 levels, the lower brightness difference lower limit is 8 levels lower than the brightness difference lower limit, and the brightness difference upper limit is 64 levels lower than the lower brightness difference upper limit. And, another method for improving display performance of the display device, comprising the steps of image-preferred color space conversion: first, selecting a color range to be processed, the color range to be processed includes a brightness range, a tonal range, and a saturation range; Determining a target color range corresponding to the color range to be processed; detecting color information of each pixel in the input image signal, and when it belongs to the determined color range to be processed, converting it to a corresponding target color range, and then outputting The processed image signal.

Preferably, the target color range has the same brightness as the color range to be processed.

The steps of adjusting the display color of the display device, the step of enhancing the dynamic depth of field of the input image, the step of enhancing the edge of the image, and the step of converting the image color space can all improve the display effect of the display device in the present invention. The method can be used alone or in combination or in combination.

The present invention adopts the above technical solution, and the beneficial effects are as follows:

1- 1 ) Adjusting with six primary colors, because of the addition of three new primary colors between the primary colors, the intermediate color that is difficult to determine which primary color should be used for correction when the display device is corrected Applying a new primary color for adjustment, this refinement is more in line with people's visual habits, making the abstract nonlinear curve adjustment intuitive and accurate. 1-2) It is preferable to use the same color of the three primary colors to create a new primary color because they are complementary colors of the three primary colors (yellow is the complementary color of blue, cyan is the complementary color of red, and magenta is the complementary color of green). It can visually make the original color rich in monotony, so that the adjustable base color covers a wide range of colors, and has a sharp contrast and difference with the existing primary colors, making it easier to select the primary color to be adjusted. 1-3) Dividing the brightness level into 64 levels, it is more appropriate to take into account the difficulty of adjusting the adjustment caused by the over-gradation and the small influence on the visibility, and the adjustment caused by the over-gradation is not accurate enough. The number of ratings.

2- 1) Determine the specific processing method according to the characteristics of each frame input screen, so that the adjustment mode is dynamic, and the display screen has a good depth of field performance, which greatly improves the visual effect; 2-2) Using histogram and averaging The statistical method of value is used as the basis for adjustment judgment, and has the advantages of realizing simple calculation; 2-3) division of high and low luminance signal values and white level expansion processing start threshold, brightness curve correction processing start threshold 2 in the preferred mode The setting is that the applicant has thoroughly studied the visual habits of the human eye through repeated and extensive experiments, and at the same time, taking into account the small amount of calculation and excellent dynamic processing effect.

3- 1) The segmentation method is used to determine the degree of edge enhancement based on the brightness difference of adjacent pixels, avoiding the existing "one size fits all" approach, and weakening the hook for areas containing high luminance difference and low luminance difference. Side processing, completely eliminates the hooking noise, and enhances the edge processing of the area containing the medium brightness difference, and can obtain clear and sharp image effects; 3-2) Experiments prove that the bright area is simplified to five, It basically meets the needs of practical applications, achieves better segmentation processing effect, and has the advantage of realizing simple calculation fast; 3-3) The division of luminance signal values in each preferred mode is based on the brightness of most existing display devices. Depending on the performance, the upper and lower limits of the difference, the upper and lower limits of the difference are set by the applicant after repeated experiments, taking into account the elimination of noise and obtaining clear and sharp image effects. In the case of the case.

4- 1 ) By adopting the method of converting the color range to be processed and the target color range, it is possible to adjust a specific color without affecting the overall color tone, saturation, and the like of other parts of the image signal, and can fully satisfy different individuals. The color preference and the need of some special purposes make the adjustment of the display picture more flexible and precise; 4-2) The limited target color range has the same brightness as the color range to be processed, which is sensitive to the change of brightness of the human eye. Avoid distortion of the image, so that the adjustment range is limited to color and saturation, because these two parameters are directly related to color.

The present invention will be further described in detail below by way of embodiments with reference to the accompanying drawings. Figure 1 shows the Munsell color system.

Figure 2 is a diagram of the Newton color circle and its prediction.

Figures 3(a)–(c) are diagrams showing the effect of a set of test pictures on a conventionally tuned display device.

4(a) to (c) are diagrams showing the effect of the test picture of Fig. 1 on a display device after six-color tone correction.

Figure 5 is an image signal 1 before processing.

Figure 6 is a histogram of the luminance information of Figure 5.

Figure 7 is a graph of brightness correction.

Figure 8 is an image signal 2 before processing.

Figure 9 is a histogram of the luminance information of Figure 6.

Figure 10 is a schematic diagram of black/white level expansion processing.

Figure 11 is a diagram showing the effect of the image signals 5 and 6 after processing.

Figure 12 is a histogram of the luminance information of Figure 11.

Figures 13(a) and (b) are screenshots of a continuous signal before and after dynamic processing.

Figures 14(a) and (b) are screenshots before and after dynamic processing of another continuous signal.

Figures 15(a) and (b) are screenshots before and after dynamic processing of yet another continuous signal.

Figure 16 is a schematic diagram of the difference zone segmentation and the edge strength.

Figure 17 is an image without edge enhancement processing.

Figure 18 is an image processed by ordinary edge enhancement.

Figure 19 is an image of the segment edge enhancement process of the present invention.

FIG. 20 is a schematic diagram of conversion of a color range to be processed and a target color range.

Figure 21 (a), (b) are the comparison chart before and after the test picture 1 is converted by the preferred color space.

Figures 22(a) and (b) show the comparison of the test picture 2 before and after the preferred color space conversion.

【detailed description】

The present invention provides a method of improving the display effect of a display device, the method being selected from the steps of: adjusting a display color of a display device, a step of enhancing a dynamic depth of field of an input image, an image edge enhancement step, and an image preference color One or several steps in the step of spatial conversion, each step will be specifically described below with different embodiments. Embodiment 1 A method for improving display performance of a display device, comprising the step of adjusting display color of a display device: dividing each pixel of the input image signal into a corresponding brightness level, the brightness level changing according to brightness of the display device Capability division can generally be divided into 64 levels; the six primary colors of the display device are respectively adjusted at different brightness levels, the six primary colors are red, green, and blue (R=Red, G-Green, B=Blue). ) three primary colors and three new primary colors, the three The new base colors of W 200 are: yellow and green (Y=Yell _0W ) in proportion to 50% each; green and blue are cyan (C=Cyan) in proportion to 50% each; , the magenta (M=Magenta) produced by the blue ratio of 50% each, when one of the new primary colors is adjusted, it is equivalent to simultaneously adjusting the two primary colors corresponding to the fixed ratio. .

The principle of color adjustment using the above method is: Each pixel contains three signals: hue, saturation, and brightness. This is the source of the 3D concept and can be expressed as Munsell color. A point in the system (Munsell Color System, as shown in Figure 1). In Fig. 1, the vertical axis represents the brightness, which can be divided into multiple levels from dark to bright, and the cross section of each brightness level is Newton color ring, as shown in Fig. 2. From the center of the Newtonian color circle to the circumference, the saturation increases in turn, and along the circumference of the ring, the hue changes between the three primary colors of red, green, and blue. The relationship between various colors and primary colors follows the following predictions: 1. The color represented by the connected lines of the two primary colors is considered to be a mixed color of two primary colors, for example: the same amount of green and red produces yellow a, which is yellow The saturation is lower than the saturation of its endpoint, because this point is closer to the center point; 2. The same amount of red and its complementary color cyan can be mixed to obtain white or monochrome ash, while a little more red produces low saturation. Red or magenta; 3. The color c produced by mixing the blue and spectral colors b in an appropriate ratio can be considered to be equivalent to the spectral color d of the same hue and the saturation is slightly lower.

It can be seen from Fig. 2 that there is a wide overtone region between the three primary colors. For a color that is not close to the three primary colors, it is difficult to intuitively determine which primary color needs to be adjusted to achieve the purpose of adjusting it. Adding a new base color makes comparison and selection more intuitive and accurate.

In the above process of separately adjusting the six primary colors, a standard picture comparison method can be used, and a sufficient number of standard pictures with sufficient color detail and brightness level are selected as the basis for adjustment, and the displayed image is compared with the standard picture. Find out the undesired color on each brightness plane, judge which color is closest to it, and then enhance or weaken the corresponding base color to repeat the above judgment and correction process. In the actual operation, you can use the normal R/G/B gamma curve correction and white balance adjustment before using the six primary colors for further color correction. Since the above adjustment process is a fine adjustment of the color deviation, the operation of each of the six primary colors can be approximated as independent. For example, the enhancement or attenuation of the yellow primary color does not affect the other five basic tones of the display. (Although it is actually the enhancement or reduction of the two primary colors of red and green at the same time, but from the perspective of human visual effects, since the adjustment of the primary color is halved, it is pure red or near red and The effects of simple green and near-green color are almost imperceptible, but only have a relatively obvious effect on simple yellow or near-yellow color. Therefore, the adjustment by this method has an intuitive and accurate effect.

In the above embodiment, the color produced by the equal matching of the three primary colors is selected as the new primary color because they are complementary colors of the three primary colors respectively (yellow is a complementary color of blue, cyan is a complementary color of red, and magenta is green). Complementary color) Can be visually made to enrich the monotonous primary color, so that the adjustable base color covers a wide range of colors, and has a sharp contrast and difference with the existing primary colors, making it easier to select the primary color to be adjusted. It is also possible to adjust the formation ratio of the new primary color, as long as it can conform to people's visual habits, and it can be used to enrich the adjustable primary color. You can even add new ones. The number of base colors, but since the new base color is always a fixed ratio of the two primary colors, too many primary colors will cause adjustment and cumbersome adjustment, so the number of six primary colors is more appropriate.

Contrast experiment: Select the S42SD-YD05 plasma module produced by Samsung SDI as the display device to be calibrated

1. Firstly, the R/G/B gamma curve correction and white balance adjustment are performed on the display device according to the conventional adjustment method, and a set of test pictures are displayed on the above-mentioned conventionally adjusted device, and the obtained image is as shown in the figure. 3(a) to (c).

2. Perform color adjustment on the display device according to the method of the present invention, and reproduce the test picture on the display device after the adjustment is completed, and the obtained image is as shown in Figs. 4(a) to (c). Comparing Fig. 3(a) and Fig. 4(a), it can be seen that after the six primary colors are adjusted, the blue sky is more blue and the grass is more green; as can be seen from Fig. 3(b) and Fig. 4(b) The image is more vivid and transparent; as can be seen from Fig. 3(c) and Fig. 4(c), the glow is more awkward. Embodiment 2 The method for improving the display effect of the display device comprises the steps of: enhancing the dynamic depth of field of the input image: firstly, the brightness information of each pixel in the determined range of the input picture is counted, and the brightness information includes the value of each brightness signal. The number of pixels and the average value of the brightness; if the ratio of the number of pixels in the high luminance signal value to the total number of sampling pixels is greater than the set white level expansion processing start threshold, white level expansion processing is performed, so that the ratio is lowered If the luminance average value is greater than the set black level expansion processing start threshold, the black level expansion processing is performed such that the luminance average value is decreased; if the ratio of the number of pixels in the low luminance signal value to the total number of sampling pixels If the brightness threshold correction processing start threshold 1 or the brightness average value is smaller than the set brightness curve correction processing start threshold 2, the brightness curve correction processing is performed according to the set correction intensity, so that the ratio is lowered or the brightness average value is raised. Hey. The black/white level expansion processing can be performed by setting the black/white level extension maximum slope, the minimum slope, the upper and lower limits of the black level extension starting point, and the upper and lower limits of the white level extension starting point. The luminance curve correction processing can be performed by setting the luminance correction intensity and the end point of the luminance correction curve.

In this example, the display device used is the S42SD-YD05 plasma module produced by Samsung SDI Co., Ltd., and its brightness is divided into 0 to 255 from 256 to 255, and 128 to 255 is the high brightness signal value, 0~ 127 is the low-brightness signal value, the brightness threshold correction processing start threshold 2 and the black level expansion processing start threshold are both 80, the white level expansion processing start threshold is 30%, and the brightness curve correction processing start threshold is 30%, sampling The range is 732X 400 pixels in the center of the input image. For the adjustment process settings: brightness curve correction intensity is 80, white level extension start point range is 215~255, black level extension start point range is 32~64, white level extension maximum slope is 1.125, black level expansion The minimum slope is 0.79687.

The specific implementation process: input image signal 1, as shown in Figure 5, its brightness information is shown in Figure 6 in the form of a histogram, the horizontal axis of Figure 6 shows the brightness signal values from 0 to 255 from dark to bright, vertical axis Indicates the number of pixels at which the input image is at each luminance signal value. It can be seen from Fig. 6 that too much image content is accumulated on the dark end of the left side, and the ratio of the number of pixels at the low luminance signal value to the total number of sampled pixels is about 45%, which is higher than the luminance threshold correction processing start threshold. First, the average brightness is about 60, which is lower than the brightness threshold correction processing start threshold 2. It can also be seen intuitively from Figure 5 that the image is dim and the details are difficult to distinguish. Identify. Therefore, the image is subjected to luminance curve correction processing. As shown in FIG. 7, the horizontal axis of FIG. 7 represents the input luminance signal value YI, and the vertical axis represents the output luminance signal value ΥΟ, which can be set by setting the luminance correction intensity and the luminance correction curve. The end point is adjusted, which is a commonly used brightness correction method in the field of image processing. The dotted line in Fig. 7 is the brightness curve before adjustment, and the solid line is the adjusted brightness correction curve.

The image signal 2 is input, as shown in Fig. 8, and its luminance information is shown in Fig. 9 in the form of a histogram. As can be seen from Fig. 9, too much image content is piled up at the extremely bright end on the right side, and the ratio of the number of pixels at the high luminance signal value to the total number of sampled pixels is about 40%, which is higher than the white level expansion processing. The threshold is activated. At the same time, the average brightness exceeds 150, which is higher than the black level expansion processing start threshold. It can also be seen visually that the image is too bright and the details of the bright area are difficult to distinguish. Therefore, the image is subjected to black/white level expansion processing. As shown in Fig. 10, the horizontal axis of Fig. 10 represents the input luminance signal value ΥΙ, and the vertical axis represents the output luminance signal value ΥΟ, which can be set by setting the maximum slope and the minimum slope. The upper and lower limits of the black level extension start point and the upper and lower limits of the white level extension start point are adjusted, which is a black/white level extension method commonly used in the field of image processing. In Fig. 10, the dotted line is the brightness curve before adjustment, and the solid line is the adjusted black/white level expansion curve.

After the image signals 1 and 2 are subjected to the luminance curve correction and the black/white level expansion processing, respectively, good performance can be obtained. As shown in Fig. 11, Fig. 12 is a luminance information histogram of Fig. 11. As can be seen from Fig. 12, the image content covers almost the entire dynamic range. It can also be visually seen from Fig. 11 that the depth of field of the image is better and the details are clearer.

The above is the processing of still images, and for continuous image signals, such as real-time television signals, it can be regarded as consisting of multiple frames of still images, and each image can be separately processed and processed. Achieve dynamic visual depth enhancement of continuous images to achieve good visual effects. Figure 13 to Figure 15 are screenshots of dynamic processing of continuous signals. Part (a) of each figure is an unprocessed picture, and part (b) is a picture with dynamic depth of field enhancement. Comparing the parts of the figure can be seen After the dynamic depth of field is improved, the picture is bright and dark, the image is more vivid, the stereoscopic effect is stronger, the picture is more layered, and the weaker light is also obviously improved.

In practical applications, in order to improve the processing speed and make a faster judgment on the processing mode of the picture, it is possible to perform sampling on a certain area without sampling all the pixels. In this case, partial area sampling is used. Embodiment 3 The method for improving the display effect of the display device comprises the steps of image edge enhancement: first, detecting a luminance difference of adjacent pixels in the input image signal, wherein the luminance difference refers to a luminance signal value of the adjacent pixel a difference value, the brightness signal value may be divided according to a brightness change capability of the display device; determining an area where the brightness difference is located according to the set upper and lower limits of each brightness difference area, where the high brightness difference and the low brightness difference are included The area corresponds to the weak hook strength, and the area where the brightness difference is in the middle corresponds to the strong hook strength; and the hook edge processing is performed according to the above-mentioned hook strength value.

In this example, the brightness signal value is divided into 0 to 255 levels from dark to light, and the brightness difference area is divided into five, and the 0 to the second brightness difference is the low brightness difference area, and the second brightness difference is the lower limit. The lower limit of the brightness difference is the low-light difference transition area, the lower limit of the brightness difference to the upper limit of the bright difference is the medium-light difference area, the upper limit of the difference of brightness to the upper limit of the second difference is the transition area of the high-brightness difference, and the upper limit of the second difference is the highest brightness signal. The value is a high-brightness difference region; wherein, the high and low luminance regions correspond to the weak edge strength B, the medium-light region corresponds to the strong edge strength A, and the high and low luminance transition regions correspond to the adjacent luminance regions. Linear interpolation of the edge strength. The difference between the segmentation of the bright region and the strength of the hook is shown in Fig. 16. In Fig. 16, the vertical axis is the bright difference and the horizontal axis is the hook strength. In the hook processing, the specific hook width value can also be set according to the size of the display screen, the number of effective pixels, etc., and can generally be selected between 1 and 2 pixels.

Contrast experiment: The S42SD-YD05 plasma module produced by Samsung SDI Company is used as the display device, and its brightness is divided into 0 to 255 by 256 levels from dark to bright. 0~51 is the low-brightness area, and 52~60 is low. In the bright transition zone, 61~134 is the medium bright zone, 135~199 is the high-brightness transition zone, and 200~255 is the high-brightness zone. That is, the upper limit of the brightness difference is 135, the lower limit of the brightness difference is 60, and the strength of the hook edge is a strong hook edge (the greater the strength of the hook edge, the higher the upper and lower overshoots, the more distinct the edge), and the edge strength B is 0, that is, no hooking processing, the sampling range is all pixels of the input image.

The test image (shown in Fig. 17) is subjected to ordinary edge enhancement processing to obtain Fig. 18; and the segment edge enhancement processing is performed by the method of the present invention to obtain Fig. 19. Comparing Figs. 17, 18, and 19, it can be seen that the image obtained by the ordinary edge enhancement process exhibits a large hooking noise, and the visual effect is rough; and the image partial expression after the segment edge enhancement processing by the method of the present invention is obtained. Clear and sharp, with no glare.

In this embodiment, in order to reduce the amount of calculation, the delay of the image display is not caused, the difference region is divided into five, and an algorithm corresponding to the single or linear interpolation edge intensity of each of the luminance regions is actually used. In order to achieve a fine edge enhancement effect, more bright areas can be divided, and the brightness difference area and the hook strength can also use various more detailed function correspondences. Experiments have shown that the five-part zoning method is more reasonable within the range that the human eye can distinguish. Embodiment 4: A method for improving display performance of a display device, comprising the steps of image-preferred color space conversion: First, selecting a color range to be processed, the color range to be processed includes a brightness range, a tonal range, and a saturation range; a target color range corresponding to the color range to be processed; the target color range has the same brightness as the color range to be processed, and is obtained by adjusting the color range to be processed by hue and saturation. The color information of each pixel in the input image signal is detected, and when it belongs to the determined color range to be processed, it is converted into a corresponding target color range, as shown in Fig. 20, and the processed image signal is output. If it does not belong to the determined color range to be processed, no processing is performed.

Specific implementation case: The setting range of brightness, saturation and hue of the color range to be processed is 0~31.75 (The meaning of this setting range is to calibrate a color range to be processed centered on the selected color. If it is 0, It means that the brightness, saturation, and tone value of the selected color are strictly the color range to be processed. If it is 5, it means that the selected color is centered +/-5 for the color range to be processed, brightness, saturation, and hue. The units are %, %, and degree respectively. Without changing the brightness, the color range to be processed is adjusted by hue and saturation to obtain the target color range. The saturation change range is 0~200% of the original value, and the hue change range is + /-16.

1 (skin tone): For test picture 1 (as shown in Figure 21 (a)), set the color range to be processed: the brightness range is set to 4.25. The saturation range is set to 0, and the tonal range is set to 12.25. The target color range is adjusted by hue and saturation: the saturation range is set to 1.1, and the hue range is changed to -2.75. The test picture 1 is converted into a preferred color space to obtain Fig. 21(b). Comparing Fig. 21(a) and (b), it can be seen that the converted person's skin color is more rosy, while the other parts of the image are not changed.

2 (blue): For test picture 2 (as shown in Figure 22 (a)), set the color range to be processed: the brightness range is set to 0.5, the saturation range is set to 1.75, and the tonal range is set to 10; After the saturation is adjusted, the target color range is: The saturation range is set to 1.39, and the tonal range is changed to -3.25. Figure 2(b) is obtained by converting the test image 2 through the preferred color space. It can be seen from the comparison of Figures 22(a) and (b) that the day after the conversion is bluer and the green is more vivid, while the rest of the image is unaffected. The above embodiments are examples when the steps are used alone. In practical applications, they can be used as needed. In principle, there is no order relationship that must be followed between the steps, and they can be arbitrarily selected and used in combination. However, from the perspective of the effect on the final effect, it is preferable to perform the steps of adjusting the display color of the display device to achieve the optimum display level of the display device, and then perform other steps. Since it is a partial adjustment of the color, the step of the image preference color space conversion should be left to the end. Moreover, each processing step is not necessarily only performed once, and multiple steps may be alternately processed as needed. For example, after the display color of the display device is adjusted, the dynamic depth of field is enhanced, and then the edge enhancement is performed, and then the dynamic depth of field is enhanced. Finally, the image display output is converted after the preferred color space conversion.

Claims

Rights request

A method for improving the display effect of a display device, comprising the step of adjusting a display color of the display device: dividing each pixel of the input image signal into a corresponding brightness level; and displaying the device at different brightness levels The six primary colors are respectively adjusted, the six primary colors are composed of three primary colors of red, green and blue and three new primary colors, and the three new primary colors are generated by pairing the three primary colors according to a fixed color matching ratio, respectively. When one of the new primary colors is adjusted, it is equivalent to simultaneously adjusting the two primary colors corresponding thereto according to the fixed ratio.

2. The method for improving the display effect of a display device according to claim 1, wherein: the three new primary colors are: red and green are yellow according to a ratio of 50% each; green and blue are according to The proportion of each of the 50% is cyan; the red and blue are magenta according to the ratio of 50% each.

3. A method of improving the display effect of a display device according to claim 1 or 2, wherein: said brightness level is divided according to a brightness change capability of the display device.

4. The method of improving the display effect of a display device according to claim 3, wherein the brightness level is divided into 64 levels. '

5. The method for improving the display effect of a display device according to claim 1, wherein: after the step of adjusting the display color of the display device, further comprising any one of the following steps or any execution order Several steps of the arrangement:

The step of ascending the dynamic depth of field of the input image: firstly, the brightness information of each pixel in the determined range of the input picture is counted, and the brightness information includes the number of pixels and the average value of the brightness at each brightness signal value; if the signal is in a high brightness If the ratio of the number of pixels of the value to the total number of pixels to be sampled is greater than the set white level expansion processing start threshold, white level expansion processing is performed to cause the ratio to decrease; if the luminance average value is greater than the set black level extension Processing the start threshold, performing black level expansion processing, so that the average value of the brightness is lowered; if the ratio of the number of pixels in the low brightness signal value to the total number of sampled pixels is greater than the set brightness curve correction processing start threshold or brightness If the average value is less than the set brightness curve correction processing start threshold 2, the brightness curve correction process is performed according to the set correction intensity, so that the ratio is decreased or the brightness average value is increased;

Step of image edge enhancement: First, detecting a luminance difference of adjacent pixels in an input image signal, wherein the luminance difference refers to a difference value of luminance signal values of adjacent pixels; The limit value determines where the brightness difference is The area containing the high brightness difference and the low brightness difference corresponds to the weak edge strength or the non-hooking process, and the area where the brightness difference is in the middle part corresponds to the strong edge strength; and then the hook edge strength value is used for the edge deal with;

Step of image preference color space conversion: First, selecting a color range to be processed, the color range to be processed includes a brightness range, a tonal range, and a saturation range; and then setting a target color range corresponding to the to-be-processed color range; The color information of each pixel in the input image signal is converted into a corresponding target color range when it belongs to the determined color range to be processed, and then the processed image signal is output.

6. A method for improving the display effect of a display device, comprising the step of: enhancing a dynamic depth of field of an input image: first counting luminance information of each pixel in the determined range of the input picture, the brightness information including values at respective luminance signals The number of pixels and the average value of the brightness; if the ratio of the number of pixels in the high luminance signal value to the total number of sampling pixels is greater than the set white level expansion processing start threshold, white level expansion processing is performed, so that the ratio is lowered If the luminance average value is greater than the set black level expansion processing start threshold, the black level expansion processing is performed such that the luminance average value is decreased; if the number of pixels in the low luminance signal value is the total number of pixels If the ratio is greater than the set brightness curve correction processing start threshold 1 or the brightness average value is less than the set brightness curve correction processing start threshold 2, the brightness curve correction processing is performed according to the set correction intensity, so that the ratio is decreased or the brightness average value improve.

7. The method of improving the display effect of a display device according to claim 6, wherein: the luminance signal value is divided according to a luminance performance capability of the display device. '

8. A method of improving the display effect of a display device according to claim 6 or 7, wherein: said high luminance signal value is a luminance signal value higher than a set white level extension starting point.

9. The method according to claim 8, wherein the brightness signal value is divided into 256 levels, and the white level extension starting point is 128 to 255. .

10. The method of improving the display effect of a display device according to claim 6 or 7, wherein: the low luminance signal value is a luminance signal value lower than a luminance threshold correction processing start threshold two.

The method for improving the display effect of the display device according to claim 10, wherein the brightness signal value is divided into 256 levels, and the brightness curve correction processing start threshold 2 is 0 to 127.

12. A method for improving display performance of a display device, comprising the step of image edge enhancement: first, detecting a luminance difference of adjacent pixels in an input image signal, wherein the luminance difference refers to a luminance signal value of an adjacent pixel. Difference; according to the settings The upper and lower limits of the brightness difference area determine the area where the brightness difference is located, wherein the area containing the high brightness difference and the low brightness difference corresponds to the weak edge strength or the edge is not processed, and the area where the brightness difference is in the middle stage corresponds to a strong Hook strength; then the hook edge processing according to the above hook strength value.

13. The method according to claim 12, wherein the brightness difference area is divided into five parts, and the 0 to the second brightness difference lower limit is a low brightness difference area, and the second brightness difference lower limit is The lower limit of the brightness difference is the low-light difference transition area, the lower limit of the brightness difference to the upper limit of the bright difference is the medium-light difference area, the upper limit of the difference of brightness to the upper limit of the second difference is the transition area of the high-brightness difference, and the upper limit of the second difference of brightness to the highest brightness signal value is highlighted. The difference region; wherein, the high and low luminance regions correspond to the weak hook edge strength or the hook edge processing, the medium luminance region corresponds to the strong edge strength, and the high and low luminance transition regions correspond to the hooks of the adjacent luminance regions. Linear interpolation of edge strength.

The method for improving the display effect of the display device according to claim 13, wherein the value of the lower limit of the brightness difference is 0% to 50% of the highest brightness signal value, and the value of the upper limit of the brightness difference is the highest brightness signal value. 50%~100%, the value of the upper limit of the brightness difference is greater than the value of the lower limit of the brightness difference.

The method for improving the display effect of the display device according to claim 14, wherein the brightness signal value is divided into 256 levels, the lower limit of the brightness difference is 0 to 127, and the upper limit of the brightness difference is 128 255.

The method for improving the display effect of a display device according to any one of claims 13 to 15, wherein: the brightness signal value is divided into 256 levels, and the second brightness difference lower limit is lower than the light difference lower limit by 8 levels, and the brightness difference is The upper limit is 64 levels lower than the upper limit of the second difference.

17. A method for improving the display effect of a display device, comprising the steps of image-preferred color space conversion: first, selecting a color range to be processed, the color range to be processed includes a brightness range, a tonal range, and a saturation range; a target color range corresponding to the color range to be processed; detecting color information of each pixel in the input image signal, when it belongs to the determined color range to be processed, converting it to a corresponding target color range, and then outputting The processed image signal.

18. The method of improving the display effect of a display device according to claim 17, wherein the target color range has the same brightness as the color range to be processed.