TW200945317A - Gamma curve compensation method, gamma curve compensation circuit and display system - Google Patents

Abstract

A gamma curve compensation method is adapted to a display system. A plurality of gray-scale images are inserted during a display process of the display system to adjust the display thereof. A gray-scale luminance of each of the gray-scale images is corresponding to one of gray levels and the gray-scale luminance of the gray-scale images are not completely the same. The gamma compensation method includes: providing a plurality of look up tables respectively corresponding to the gray levels; searching a particular look up table corresponding to a particular gray level from the look up tables when choosing the particular gray level from the gray levels to define the gray-scale luminance of one of the gray-scale images; and implementing a gamma compensation based upon the particular look up table to keep the gamma curve unchanged during the display process. The present invention also provides a gamma curve compensation circuit and a display system can perform the above-mentioned gamma compensation method.

Description

200945317 IX. Description of the Invention: [Technical Field] The present invention relates to an image display technology, and more particularly to a pulsed drive display system and a gamma curve compensation method and circuit therefor. [Prior Art] ❹

At present, one of the main ways to solve the motion blur phenomenon of the motion picture of the liquid crystal display system is the impulse driving (impUise_type Driving), which is also the technique of fixed black insertion (Biack inserti〇n). However, in the pulsed drive mode, the 'Fiack Insertion' technique causes the screen to be Luminance Decay and causes a noticeable problem with flicker. In addition, the reaction time of the liquid crystal is nonlinear when pulled up by the zero gray scale. When the initial gray scale is lower gray scale, the pulling time is much higher than other higher gray scales, which is not conducive to improvement. Ghost phenomenon. In order to improve the aforementioned brightness attenuation, flickering and the like and the transition speed of the liquid crystal to reduce the smear phenomenon, a Dy_icna Insertion technique is proposed, which determines the inserted according to different screens. Long stage 佶. However, in the process of dynamically inserting gray scales, there will be different gamma output when inserting different grayscale values, resulting in dark unevenness in the image = inner same color will be different in different regions. Yan Ji. The purpose of the trick is to provide a method such as a code curve compensation so that the gamma curve of the system is not changed during the display process. ... the re-visit of the present invention - the gamma curve shows that the gamma curve of the system does not change during display. A further object of the present invention is to provide a system that does not change the gamma curve of 200945317 during display. Other objects and advantages of the present invention will become apparent from the present disclosure. The disclosed technology is specifically designed to achieve one or a part or all of the above objectives or embodiments thereof, and a gamma curve compensation method, which is suitable for the invention - inserting a plurality of grayscale images to adjust the display system. Now. The gray-scale brightness of the mother-gray image is the grayscale brightness of the shirts. The grayscale brightness of the two images is not exactly the same: when the same grayscale values provide the corresponding multiple = in the selection of 14 grayscale values One of the special / find the table, when 'from the lookup table cap selection 鄕 阶 _ _ _ ^ ^ ^ ^ ^ ^ Use this specific lookup table as a gamma curve compensation test, to = show system The gamma curve does not change. .', /,, and - The present invention provides a gamma gambling circuit for use in a system. The gamma curve compensation circuit includes: a medium ❹ gray scale decision secret, a multi 4 and a lookup compensation circuit. Shadow Jian U Road t display system (4) input image signal and generate corresponding _ data signal. Inserting a gray-scale mosquito according to the input signal to determine the grayscale brightness of the grayscale image of ^, and outputting the grayscale image. The multi-guard is electrically coupled to the image generating circuit and the insertion gray-scale determining circuit for selecting the original display signal outputted by the multiplexer from the original output image of the gray Pnv image. The compensation circuit is electrically connected to the multiplexer to receive the original display signal, and the lookup and compensation circuit provides different lookup tables, and selects & corresponds to the gray in the received original display signal. A specific lookup table of grayscale brightness of the order image and gamma curve compensation of the original display signal according to the specific lookup table. 7 7 200945317 Another embodiment of the present invention provides a receiving end, the aforementioned gamma tree compensation system, including: The power supply and image are used for display operation; f彡image=screen. The power supply provides power to display the original received input image signal; the display and compensation circuit performs a gamma====== compensation circuit check "a certain one of the values of the plurality of processes of Na" - a specific gray When the order value is used to display the gray scale brightness of one of the plurality of grayscale images, the lookup table from the lookup table in the lookup table, and the basis of the lookup table 'Γ compensation is adjusted to adjust to a uniform normalized gamma. Ma = ma ized Gamma) value (such as Gamma2 $. Therefore, the gamma curve of the system can be changed during the display process, thereby improving the display performance of the display system. For the above and other purposes of the present invention, The features and advantages of the present invention will become more apparent and will be described in detail below with reference to the accompanying drawings. [Embodiment] _ ^ 凊 Referring to FIG. 1 ' is a display according to an embodiment of the present invention A circuit block diagram of the system 10. In the present embodiment, the display system 1 includes a power source n, a video receiving terminal 13, a gamma curve compensation circuit 15, and a display screen 17. The power source u provides power for the display system 10 to perform. Operation, image reception 13 is for receiving an input image signal, and the display screen 17 is for displaying an image. The gamma curve compensation circuit 15 includes an insertion gray level decision circuit 150, an image generation circuit 152, a multiplexer 154, and a lookup and compensation circuit 156. The gray scale determining circuit 150 determines the gray scale brightness of the gray scale image to be inserted according to the input image signal, and outputs the gray scale image after determining the gray scale brightness. The image generating circuit 152 receives the input according to the image receiving end 13 . Image signal 8 200945317 ^Select the grayscale image and the 2nd channel image signal from the road, as the multiplexed cry 1ς/1 ^ We have the starting number. The search and compensation circuit 156 is electrically coupled The original display shows that the fault is at most 154 to indicate the signal. It is worth noting that the 'finding and compensating circuit 156 provides different ^ - lookup tables, and the choices in these lookup tables correspond to the received ones. A specific lookup table of the grayscale brightness of the original display image, ii according to the specific lookup table to start the gamma gamma compensation, so that during the display process, the gamma curve of the display system H) is not The result of the original display signal after the gamma rotation compensation by the search and compensation circuit 156 is sent to the display screen ο. - # and referring to FIG. 2, which is a gray scale decision circuit according to an embodiment of the present invention. 150 circuit block diagram. Inserting gray scale decision circuit (9) includes color space conversion module 1502, analysis module 15〇4, insert gray scale limit module 15〇6 = gray scale generation module 15G8. Color space conversion module (10) Converting the input image signal received by the image receiving end 13 into color space distribution data. The analysis module 1504 is electrically connected to the color space conversion module 15〇2 to receive the color space distribution. The analysis module 1504 analyzes the color space distribution. The distribution of the data in the color space and output the corresponding analysis signal. The grayscale limiting module 1506 is configured to store the grayscale limiting parameter, and the grayscale generating module 15〇8 is electrically coupled to the analyzing module 1504 and the grayscale limiting module 15〇6, thereby The analysis signal outputted by 1504 is matched with the gray scale limit parameter stored in the grayscale limit module 15〇6 to determine the grayscale brightness of the grayscale image to be inserted and output the grayscale image. The specific grayscale image to be inserted is the segmentation (D丨v丨s丨〇n) as the single 9 200945317 bit, and the same segmentation inserts the same grayscale value, and each segment can be a line, a segment. (Segment), a frame (Frame) or several frames. The analysis module 15〇4 can use a histogram analysis method or other well-known analysis methods such as a Minimum Gray Insertion method and a Threshold method.

The pre-inserted grayscale value of each segment is determined, and the output analysis signal can represent the pre-inserted grayscale value. Since the grayscale value of the image is generally divided into 255 levels, that is, gray scales L0 to L255; the gray scale limiting module 15〇6 of the embodiment can limit the range of the inserted grayscale value to a specific range (for example, L〇~L30), and each adjacent sub-subsidiary will limit the change range of the inserted gray scale (that is, the level difference of the gray scale to be inserted in the adjacent two partitions is not greater than a preset value, for example, 5 or 1〇 ) or smoothing the adjacent segmentation. The grayscale generation module 15〇8 obtains the pre-inserted grayscale value determined by the analysis module 1504 and cooperates with the grayscale restriction parameter stored in the grayscale restriction module 15〇6 to obtain the final grayscale image to be inserted. Grayscale value (also known as 'grayscale brightness') and output this grayscale image. Referring to FIG. 3, the display system 本 in the present embodiment may further include a backlight module 19 to provide a light source (not shown) to illuminate the display screen 17. In this case, the display system 10 can be a liquid crystal display device. Further, the display system 1 can include a backlight module control circuit 158 electrically coupled to the multiplexer 154 and controlled according to the grayscale brightness of the grayscale image in the original display signal output by the multiplexer 154. The backlight module driving signal of the backlight module 19 is driven to adjust the brightness of the light source in the display system 10, so that the brightness of the display surface of the display system 10 during the display process is consistent with different insertion gray scales and corresponding lookup tables. As a result, the brightness of the display system 10 is unchanged. The backlight module control circuit 158 can be integrated into the gamma curve compensation circuit 150 (as shown in FIG. 3) or can be a circuit structure other than the gamma curve compensation circuit 150. A gamma curve compensation method of the foregoing display system 10 will be described. In the display system, a plurality of grayscale images are inserted during the display process to adjust the display 7F performance of the display system. The grayscale brightness is selected by a plurality of grayscale values, and the grayscale luminances of the grayscale images are not completely identical to each other. The gamma curve compensation method may include the following steps: 2) providing a plurality of corresponding lookup tables for different grayscale values; wherein, the lookup tables may be searched and compensated by the gamma curve compensation circuit 15 156 available. (2) When one of the gray scale values is selected as the gray scale of one of the gray scale images, the lookup and compensation circuit 156 selects and selects a specific gray scale from the lookup tables. The corresponding-specific record; and (3) use this specific lookup table as the basis for gamma curve compensation, so that the gamma curve of the display system 1〇 is unchanged during the display process, for example, adjusted to uniform standardization Gamma value (such as Gamma2.4). Referring to FIG. 4, although the gamma curves after inserting different gray scales all conform to a normalized gamma value (such as Gamma 2.4), the actual brightness of the inserted gray scale images may still be different; therefore, this embodiment The gamma curve compensation method may further include a redundancy correction step (4) of adjusting the brightness of the light source in the display system to make the brightness of the display system unchanged during the display. Specifically, the correction of the brightness can be achieved by the backlight module control circuit 158 adjusting the backlight module driving signal used to drive the light source of the display system 10, such as a Pulse Width Modulation (PWM) signal; The higher insertion gray scale value corresponds to a smaller pulse width, and the brightness curve of the grayscale image of the higher gray scale (for example, gray scale L15) is maintained by using an appropriate pulse width modulation signal (also That is, without sacrificing the maximum brightness and without increasing the input power), the luminance curves of the grayscale images of the lower grayscales (for example, grayscales L10 and L5) are mapped upwards with a larger pulse width (Fig. 4). The middle dashed arrow 11 200945317 refers to the result that the exemption curve and the gamma curve will be consistent after the different insertion gray scales are matched with the corresponding lookup table. ~ In addition, in the display process of inserting a plurality of grayscale images as described above, as the brightness of the highest grayscale increases, the minimum grayscale luminance also increases, thereby causing poor contrast of the display system 10 during display. Therefore, as shown in FIG. 5, the gamma curve compensation method of this embodiment may further include a contrast enhancement step (5) of displaying a portion of the light-closed wire to suppress the increase in brightness of the low-gray scale surface. Specifically, when the face is a low gray level, the gray level insertion period is entered in one frame, and the light source can be turned off (B/L OFF) by the backlight module driving signal provided by the backlight module control circuit 158. So - to increase the contrast since the unnecessary brightness of the low gray scale surface is removed. In Fig. 5, B/L ON means that the light source is in the = bright state, and Td and Tb are the charging time of the display signal, and Td + Tb can be equal to one frame horizontal scanning line time (1H Time). The gas τ, as described above, the embodiment of the present invention provides a plurality of corresponding lookup tables for different grayscale values, and a plurality of lookup tables in which one of the grayscale values is selected is displayed during the display process. When the grayscale brightness of one of the grayscale images is selected, a specific lookup table corresponding to the specific grayscale value is selected from the lookup table and the specific lookup table is used as the basis for the gamma curve compensation to adjust to the uniform standardization. Gamma,. Therefore, the gamma curve of the display system can be made unchanged during the display process, thereby improving the display performance of the display system. Further, by controlling the light source to correct the brightness of the face and suppressing the brightness increase of the low gray level face to increase the overall contrast, the display performance of the display system can be better. While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection shall be subject to the definition of the scope of the patent application. In addition, any embodiment of the present invention or 12 200945317 Finance 1 achieves all the purpose or special features of the present invention: the second part and the title are only used to assist in the search of patent documents, and are not intended to limit the present. Scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit block diagram of a display (four) according to an embodiment of the present invention. Fig. 2 is a block diagram of the gray-scale mosquito circuit of the present invention.

3 is a circuit block diagram of a display system in accordance with another embodiment of the present invention. 4 is a bright view of different gray scale values for different insertions according to the present invention. FIG. 5 shows a grayscale insertion period in a frame when the facets belong to a low gray level according to an embodiment of the present invention, and the light source is turned off. . [Main component symbol description] 10 : Display system 11 : Power supply 13 'Image receiving end 15 : Gamma curve compensation circuit 150 : Insert gray scale decision circuit 1502 : Color space conversion module 1504 : Analysis module 1506 : Insert gray scale limit Module 1508: grayscale generation module 152: image generation circuit 154: multiplexer 156: search and compensation circuit 158: backlight module control circuit 13 200945317 17: display screen 19: backlight module L15, L10, L5: gray Order value

Td, Tb: display charging time of the signal

14

Claims (1)

200945317 X. Patent application scope: A gamma curve compensation method is applicable to a display system. The display system f is displayed, and multiple grayscale images are inserted in the process to adjust the display of the display system: performance The grayscale brightness of the grayscale image is formed by selecting one of a plurality of grayscale values. The gamma curve compensation method includes: /, providing corresponding plurality of lookup tables for different grayscale values; The grayscale value of the grayscale value is formed into the grayscale scenes, and the Φ lookup table corresponding to the special dimension value is selected from the lookup tables; and the §^ special lookup table is used. As a basis for gamma curve compensation, the gamma curve of the display system is made constant during the display process. 2 The gamma curve compensation method described in item 1 of the patent scope includes: Miscellaneous. The brightness of one of the light sources in the system is not changed to make the brightness of the picture that is not systematic in the display process. The gamma gamma compensation method of the second application of the patent specification (4), wherein the brightness of the light source in the system is achieved by adjusting the pulse width modulation signal used when driving the light source. The gamma curve compensation method as described in the second aspect of the patent specification 81, further comprising: turning off the light source during a part of the period of the drawing process. 5, such as the general (four) 1 rhyme material scales are still green, including: Yu Heke Cheng's section of the material (four), please shoot a light source. In the present invention, the gamma-compensation circuit is applied to a display system, and the image-generating circuit generates a corresponding-original round-out image signal according to the received image signal received by the display (4); 15 200945317 Inserting a gray scale determining circuit to determine the gray pm of the grayscale f image to be inserted according to the input image signal and output the grayscale image; the solar device is electrically coupled to the image generating circuit and the insertion The gray level determines the electric (the) output image of the county without the gray-scale image, which is selected as an original display signal output by the multiplexer; and the β_""search and compensation circuit, which is connected to the multi-receiver The original display signal 'The lookup and compensation circuit provides different multiple break tables, and selects - specific fields corresponding to the gray scale brightness of the grayscale image received by the original explicit shot in the lookup tables The gamma curve compensation is performed on the original display signal according to the fixed lookup table. 7. The gamma curve compensation circuit described in claim 6 of the scope of the patent application further includes: - a backlight module control circuit, electrical secret To the multiplexer, and according to the grayscale brightness of the grayscale image in the original display signal output by the multiplexer, the control is used to drive the backlight module driver of the backlight module in the display system. 8. The gamma curve compensation circuit inserted into the gray-scale decision circuit according to item 6 of the patent scope of the application includes: "Using the air, changing the module" converts the input image received by the display system into a color space distribution data; a knife analysis module, 'a is connected to the color space conversion module to receive the color space distribution data', and the analysis analyzes the distribution in the color space to output a corresponding-analysis signal; a gray scale limit module, a storage-gray scale limit parameter, and a gray scale ί , group, electrically consuming to the analysis module and the inserted gray scale limit module, and the difficulty is based on the age (four) number, and the insertion is matched The gray scale limit parameter stored in the gray scale limit module n 16 200945317 is to insert the gray scale brightness of the gray scale image, and input (four) gray scale 9 , as described in claim 6 of the gamma curve display system package A display system includes: a power supply for supplying power for operation of the display system; an image receiving end for receiving an input image signal, a gamma curve compensation circuit, comprising: #蟮衫像产生电路' generates an original output image signal corresponding to an input image received by the display system; ', the grayscale decision circuit determines the desired gray-in- Gray-scale brightness of the order image, and output the gray-scale image; n, connected to the image generation circuit and the inserted gray-scale=circuit, and select one of the output image and the gray-scale image as the 忒The output of an original display signal; and the display-second search ί compensation circuit 'electrically lightly connected to the multiplexer to receive the original == shout' the money and the compensation circuit provides not (10) multiple money tables, and Selecting, in the received original display signal, the grey grayscale degree-free specific lookup table, and performing gamma curve compensation on the initial display signal according to the specific lookup table; The F screen 'is used to display the original display __ New Zealand and the compensation electric power slightly into the gamma curve compensation after the gentleman 11, as shown in the patent application scope 10 display system, including: - back group , provide the face, shoot to the job show honor. For example, the display system described in claim U of the patent scope further includes: The backlight module control circuit is electrically connected to the multi-mode and outputs the gray-scale brightness of the gray-scale image of the primordial money towel, and controls a backlight module for driving the backlight module. 13. If the application is in the scope of item ω, the obvious 遽==. The order determining circuit comprises: a system that is not inserted into the gray color space conversion module, and converts the display signal into a color space distribution data; and receives the input image color space to the color space conversion module to receive The color is inserted into the gray P white limiting module to store a grayscale limiting parameter; and the grayscale generating module is electrically connected to the analyzing module and the inserted grayscale limit, and the red gray is generated by the module according to the grayscale The analysis signal outputted by the analysis module determines the grayscale brightness of the grayscale image to be dragged in accordance with the grayscale limit parameter stored in the grayscale limiting module, and outputs the grayscale image.