TW200908727A - Method and apparatus for dynamic contrast enhancement - Google Patents

Abstract

A method and apparatus for dynamic contrast enhancement is provided. The apparatus at least comprises a histogram calculator, a low-pass filter, a blending unit and a luma remapper. By means of blending a content-based histogram with a user-defined histogram, the invention solves a problem that the mean luma value is shifted too much due to a drastic adjustment.

Description

200908727 IX. INSTRUCTIONS: [Technical field of invention] This is about dynamic contrast enhancement, especially about mixing a content-based histogram and a use. User-defined histogram dynamic contrast enhancement device and method thereof. [Prior Art]

The following is a convenient description. In the scope of this specification and the patent application, "luminance" means - a component of the input image data value - the user's visual perception intensity of the component and a displayed image data value. (perceived intensity), wherein the input image data value itself may be in the form of a digit or analog, which will eventually be displayed on a digital or analog display, such as a cathode ray tube (crt) or a liquid day display (LCD). . "chrominance" means that the input 'v is another component of the shell value, which is related to the user's visual perception color (eQ(4)) of the displayed image data value. As for the hue and saturation|ati〇 n) A standard commonly used to define color perceptions, which together define chromaticity. In addition, the "Dynamic Contrast Enhancement" table 8 cabinets according to the redundancy distribution, can be too dark or too bright to be able to rectify? A "user-defined histogram" means a histogram that has been previously defined or dynamically programmed during the process. Since the conversion function (tmnsfer functi〇n) must be dynamically based on the inside of the image: the complexity of its adjustment can be imagined. In the field of image enhancement, in the field of processing, many methods for image contrast adjustment have been studied. The υ α α 忐 忐 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , 200908727 equalization). The existing technology is mostly improved according to the histogram equalization method, and the approximate knife can be two types. The curve selection method and the curve calculation method. The curve selection method is to provide a set of conversion functions in advance, and then select one of the group of conversion functions according to the motion picture content. This technique is represented by the US Patent No. 5, 8-8. However, the composition of the video content is quite complicated and it is difficult to predict. The other group conversion function is selected to be correctly compensated, so the actual application - the scope is limited. "The curve operation method does not need to provide a set of conversion functions in advance, but the conversion function is obtained according to the pure dynamic operation of c, but this method has been adjusted so that the mean value of the mean value is too large. Disadvantages, for example, are images taken at night like daytime. In addition, the curve calculation method also makes the gradient changes of the π degree level discontinuous. This technique is based on Kim in 1997 (, 'Contrast Enhancement Usmg Brightness Preserving Bi-Histogram

Equalization», Y.-T. Kim, IEEE Transections on Consumer Electronics Vol_43, N〇1 Feb 1997) The proposed method is representative and the method proposed by 'K i in has two problems: the first problem is - different The image brightness distribution has the same average brightness; the second problem is that the brightness mean is extremely sensitive to outliers, in other words, the brightness values of relatively few pixels are far from the brightness mean, but The average brightness value has a large impact. In order to solve the above problems, the present invention has been proposed. SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a dynamic contrast enhancement apparatus that mixes a histogram based on image content and a user-defined histogram of 6 200908727. To achieve the above object, the dynamic contrast enhancement apparatus of the present invention comprises: a histogram calculator for calculating a current frame-brightness histogram, U〇w-pass filter, connected to The histogram controller is configured to perform a low pass filtering process on the luminance histogram and generate a filtered histogram; a mixing unit connected to the low pass filter according to a blending weight Mixing the filtered histogram with a user-defined histogram and generating a mixed histogram; and a remapper coupled to the mixing unit for generating a conversion function based on the mixed histogram, And according to the conversion function to map the current page frame.

Another object of the present invention is to provide a dynamic contrast enhancement method comprising the steps of: calculating a luminance histogram of a current page frame; performing a low pass filtering process on the luminance histogram to generate a filtered histogram; Weight, mixed § 滤 filter, wave histogram and a user-defined histogram to generate a mixed histogram; according to the mixed histogram to generate a conversion function; and, according to the conversion function to map the current page frame . The above and other objects and advantages of the present invention will be described in detail below with reference to the accompanying drawings. [Embodiment] The dynamic contrast strengthening device of the present invention can be implemented by using any one of hardware, software 'firmware, or any combination of the first three. For example, an example of a pure hardware implementation is a field. A field programmable gate array (FPGA) design, or a specific application integrated circuit (application specific integrated 7 200908727 circuit ' ASIC) design, and the hardware and firmware implementation example is a digital jg processor (digital signal processor, DSP) and its built-in firmware combination. Figure 1 is a block diagram showing the architecture of a first embodiment of the present invention. Referring to FIG. 1 , the dynamic contrast enhancement apparatus 100 of the present invention includes a histogram calculator 110, a low pass filter 12A, a weight calculator 13A, a mixing unit 140, a norma lizer 170, and A brightness mapper 150. Because a current page frame 160 is composed of multiple input image data (or pixels)

The composition 'each input image data value can be divided into a luminance component and a chrominance component, and the histogram calculator 计算 calculates the current luminance component (or data) of all the pixels of the current page frame 丨6〇 One frame brightness histogram of page frame 16〇. After receiving the luminance histogram, the low pass filter 120 performs a low pass filtering process on the luminance histogram to generate a filtered histogram. Fig. 2 is a comparison diagram of two conversion functions, wherein the conversion function 22 is obtained by directly equalizing the luminance histogram 21, and the low-pass filtering processing is not performed'. As for the generation of the conversion function 24, The luminance histogram Μ is transmitted to the low pass; the t wave mx performs low-pass filtering processing, and obtains the chopping straight=Fig. 23 and then equalizes the crossing histogram 23. Comparing the two transitions, functions 22, 24, it can be clearly seen that the gradual change of the transfer function 22 is relatively discontinuous compared to the gradual change of the conversion function 24. In other words, the function is saved; the function 22, the conversion function 24 has more gradient levels to be guaranteed (slightly U is correctly determined in subsequent procedures - the size of the blending weights (discussed later). According to the invention, the user Custom histograms have been pre-defined to be dynamically stylized at 8 200908727 and / or during implementation. For example, the user can be a bin-box (the histogram is made up of multiple bins) The area is composed, each phase area represents a specific brightness range.) Specify a intensity (magimude) or count value to preset - user-defined rectangular circle. In order to mix the filtered histogram and the user-defined histogram, Both of these must be normalized (n〇rmalize) to an identical reference datum before entering the weight calculator 130. For example: 256 (total number of luminance levels). In this way, if the total number of pixels of the filtered histogram is As long as bt〇tal, the normalization process performed by the normalizer 就是7〇 is to reduce the filter histogram from the total number bt〇tal to 256. For example, if L (total number of brightness levels) = 256 and bsize (Number of total box types) =8, then each box type area width (or gray level distance) = 32 brightness level. First, the normalizer i 7〇 calculates the total number of pixels of the filtered histogram btotal = |; - fine (7), where bin(1) is the filtered histogram The count value of the first box type area. Then, the normalizer 17 calculates the count value of each box type by calculating bin(i) -(bin (i) X btotal), where i is one Integer and covers a range from 0 to (bsize-i). Please note that if the filtered histogram and the user-defined histogram have the same reference before being sent to the weighted benefit 130, that is, The same total number of brightness levels 'the normal contrast in the dynamic contrast enhancement device of the present invention can be omitted. The weight calculator 1 3 0 receives the filtered histogram' and according to the filtered histogram, the user-defined histogram The graph and a preset blending parameter do βΖ·„ versus scale (discussed later) to generate a blending weight. The blending unit 1 40 further mixes the ferrometer histogram according to the blending weight sw′ The user customizes the histogram 'and produces a mixed histogram. 3rd The system displays 200908727 to generate a hybrid hybrid-filter histogram and a user-defined histogram histogram. For T, please describe the weight calculator 130 and the mixing unit according to the 3rd and 4A-4C diagrams. 14〇 operation, in which the total number of brightness levels = 2 5 6, box fine area her 砉 f - j4 a · phase jade [- (four) number -4, so the mother - box type area width = 64 brightness level. = Refer to Figure 3 The maximum juice value (hereinafter referred to as) in any box type of the chopping histogram 31 is equal to 1Μ, and the user is from the Dingzhifang® 32>[壬-box type zone The maximum count value (hereinafter referred to as equal to 64, the size of the count value represented by the parameter, qing is determined by the weight calculator 13 (). The weight calculator 1 3 产生 is based on one of the three mixed parameters and the proportional relationship curve and a proportional value (= 叩) to generate a mixed parameter ζ ζ „. The present invention provides three mixing parameters and The relationship between the ratios, as shown in Figures 4A to 4C, is trapezoid, staircase, and nonlinear (n〇n Hnear). The trend of the relationship between the three mixed parameters and the ratio is roughly similar. , that is, when the scale value (= close to i, the filter histogram is similar to the brightness distribution of the user-defined histogram, the blending parameter is set to 1; and when the scale value is larger, the mixed histogram is indicated) The brightness distribution of the filtered histogram is more and more similar, and the value of the mixing parameter is gradually increased. Finally, when the ratio is greater than a critical value, the mixing parameter ah is set to a constant (by 4A). For example, the ~4C graph has a constant equal to 2). However, in the application implementation, the three relationship curves have different degrees of difficulty: the stair type relationship curve (Fig. 4B) is the easiest to implement 'relatively' non- The difficulty of implementing the relationship curve (Fig. 4C) 10 200908727 degrees is the southernmost. It is assumed that the mixing parameter (1)·„ (=1 _5) is generated according to a proportional value (=maxZ^/wep=128/64 = 2, such as Figure 3 shows one of the three mixed parameters and the ratios in the 4th to 4th graphs. According to the above parameters, the weight calculator 13〇 can dynamically generate a blending weight SW. In this embodiment The weight calculator 130 uses the following mathematical equations to determine the blending weight: maxbin x in; + step x (1-^) = dgain x step...........(A) The value § ten nose device 13 0 only needs to substitute 28, and do d«=1.5 into equation (A), and can obtain the mixed weight value chat = 〇 · 5. Then, the mixing unit 140 is based on the calculated blending weight value (10) ( =〇5), the hybrid wave histogram 3 1 and the user-defined histogram 3 2, step by step to create or generate a mixed histogram 33 in a manner of bin-bin mixing. The final count value of each box type of the mixed histogram 33 can be obtained, for example, the final count of the second box type area of the mixed histogram 33 The value is equal to 96 (=128 X 0_5 + 64 X 〇·5), and the final count value of the first box type is equal to 64 (=64 X 0_5 + 64 X 0.5), etc. In equation (A), The function of _ζ>2Χ^φ) is used to limit the count value of each box type to avoid the situation of brightness distribution adjustment and over-enhancement. Finally, the 'brightness mapper 17 0 receives the mixed histogram and executes The integral operation is to generate a conversion function, which is then mapped according to the conversion function. It is to be noted that the parameter w of the present invention is not the only count value that is uniquely represented in any box type of the filter histogram and the user-defined histogram. The similarity ^ can be any value selected from a preset range, which is the maximum count value to the Nth count value in all the 200908727 type zones of the filter histogram. Where N is equal to the total number of box-type regions of the filtered histogram divided by 3 and N is a positive integer. For example, if the total number of box-type regions of the filtered histogram is equal to 15, it may be selected from any box type region of the filtered histogram, and has a maximum count value of 5 (N=15/3=5) Any one of the five count values of the large count value. In addition, the similarity / / can also be a mean value within a predetermined range 'the preset range is the third largest count value to the Nth largest count value in any of the box type regions of the filtered histogram, wherein , N is equal to the total number of box-type regions of the filtered histogram divided by 3, Μ, N are positive integers and N > M. For example: When M=2 and the total number of box-type areas of the filtered histogram is equal to 15, then the second () maximum count value of all the box-type areas of the filtered histogram seems to be 5th ( N==l5/3=5) One of the five count values of the large count value. Similarly, it may be any value within a preset range, which is a maximum count value to a maximum P count value in any box type area of the user-defined histogram, where p is equal to The total number of box-type areas of the user-defined histogram is divided by 3 and p is a positive integer. In addition, the "printing may also be a mean value within a preset range, which is the Qth large count value to the Pth large count value in all the box type areas of the user-defined histogram, wherein, P The total number of box-type areas equal to the user-defined histogram is divided by 3' Q, P is a positive integer and p > Q. Figure 5 is a schematic diagram of the architecture of the second embodiment of the present invention. The invention dynamic contrast enhancement device 5〇〇 includes a histogram calculator 110, a low-pass filter 12〇, a mixing unit 14〇, a histogram limiter 5′′, a temp〇ral filter 520, A brightness mapper 150, a normalizer 170, and a scene detector 530. Phase 12 200908727 Compared to the first embodiment, the dynamic contrast enhancement device 5 of the second embodiment lacks a weight calculator 130, but the histogram limiter 51 〇, the time domain chopper 520, and the scene detector 53 多 are added. As for the components having the same reference numerals in the second embodiment and the first embodiment, the same functions are also provided. 'Not to be repeated here. In the second embodiment, the mixing list The meta 14 利用 system uses a fixed '(Static) blending weight to blend the filtered histogram with the user-defined • histogram to gradually create a mixture (in a histogram) by mixing one box area at a time. In other words, Binb(1)=binf(1)x(10)+ Μηυ(1)χ(1-predicate), where binb(1), binf(i) and binu(1) are the count values of the mixed box histogram, the filtered histogram and the second box type in the user-defined histogram, respectively. In order to avoid the histogram brightness distribution adjustment is too intense, a histogram limiter 510 is set after the mixing unit 14〇. The histogram is limited to 5 1 0. The limit value of each box type in the mixed histogram must fall on a specific Range: (G1 X price) and (G2 X wep), where "prints represent the largest count in all box types of user-defined histograms; values, G1, G2 are positive integers and G2 > G1. That is to say, if the raw count value of any box type of the mixed straight square graph exceeds (G2 χ “卬), the final count value of the box type area will be the histogram limiter 5 1 Decrease to (G2 χ WM); conversely, if mixed If the raw count value of any box type of the histogram is lower than (G1 χ , the final count value of the box type area will be increased by the histogram limiter 510 (G1 χ 尸). Please continue to refer to Figure 5 'Scenario The detector 5 3 〇 calculates the histogram distribution gap between the two pages before and after the calculation, and compares the gap with a threshold τ. When the difference is greater than the threshold ,, the scene detector 53 determines that a field has been generated 13 200908727 Scene change (that is, in a video sequence)

A scene transition is detected and a consistent energy (e n a b 1 e d) transition signal is generated; otherwise, the scene detector 530 generates a disabled transition signal. If the state of the transition signal is enabled, it means that the scene between the two pages is sufficiently wide, and the time domain filter 52 directly outputs the mixed histogram of the current page frame; otherwise, if the state of the transition signal is When disabled, it indicates that the video sequence is currently smooth and smooth on the time and space coordinates. The time domain filter 520 mixes the mixed histogram of the current page frame with the mixed histogram of the previous page frame to mix one box at a time. The way of the area, to gradually establish a time domain histogram, for example, the current page frame and the previous page frame are mixed with a weight equal to 0.25 and 〇 75 respectively. Thereafter, the time domain filter 52 传送 transmits the time domain histogram to the luminance mapper 丨5〇 to generate a conversion function and perform mapping processing. Figure 6 is a schematic diagram of the architecture of the third embodiment of the present invention. The invention dynamic contrast enhancement device 6〇〇 includes a local brightness histogram=a calculator 610, a low-pass waver 120, a weight calculator 13〇, a sigma unit 14 守 day-domain filter 520, a brightness mapper 150, - field: detector 53 〇, - chromaticity mapper 620 and a regularizer 17 〇. The third embodiment has the same functions as those of the first and second embodiments, and the same functions are not described herein. Generally, the darkest box area in the luminance histogram usually has a lower::noise ratio (signaM〇_n〇ise) area I,: a low-brightness signal in two areas It is easy to mix with noise - η 绝 If. According to the above reasons, there is no absolute necessity for the contrast enhancement of the darkest box type. I don't know the local brightness histogram of a. 14 200908727 Calculator 6 1 0 only for a pre-exception · Ming pg · in m / 孭D The area of the type zone (for example, the i-th box type to the seventh box type area of the y foot, assuming that the total number of brightness levels is 2 (4), generating a partial brightness histogram without calculating the second box type area (ie, Do not look at the count value of the region. Then the low pass chopper 12 执行 performs low pass filtering on the local luminance histogram to generate a filtered histogram. Before performing the normalization process, the normalizer 17Q pairs all The filtered histogram of the input frame is set (or limited). The count value of the box type is equal to a preset constant F. After that, the regularizer 17Q is the heart for the total number of pixels (4).

Filter the histogram to normalize the count value of the preset box type range (the first box type...). The above "=" can not only avoid the black side of the face (black ba〇 interference, but also avoid it. The brightness contrast is over-enhanced. In addition, the count value of the fixed darkest box area can also improve the user's perception of brightness contrast and avoid the problem of overshoot. In theory, assign to, ignore the area j The larger the constant Fl value of one box type area, the smaller the number of remaining brightness bits P white that can be allocated for the preset box type area (1st box type to 7th box type area). Note that the "ignore" area is not limited to the second box type area, and the constant value size and the preset box type area size can be modified according to requirements. According to the third embodiment, the brightness information can be different. The chromaticity contrast is enhanced in a prior art manner. The luminance mapper 150 produces a chrominance gain based on the conversion function and an input luminance level X. Specifically, the luminance mapper 150 receives the conversion function and receives - lose The brightness component X of the pixel (or - input image data) and a corresponding wheel 15 200908727 brightness level Κ is obtained in units of each brightness level (^ ieve by level basis). Then, the brightness mapper The luminance gain of the input pixel is modified to produce a chrominance gain of the luminance component of the rounded pixel. The chrominance gain is generated on a bin by bin basis. Accordingly, the chrominance mapper 62 can apply the chrominance gain to one of the input luminance pixels of the rounded pixel. The following examples of FIGS. 7A and 7B are used to illustrate the luminance mapper 15〇. Operation with chroma mapper 620. Figure 7a shows an example of a two-square histogram and its corresponding transfer function. Figure 7B shows the conversion between the chroma gain and the bin index based on the transfer function of Figure 7A. A diagram. In the time domain histogram of Fig. 7A, assuming L (the total number of luminance levels) = 256 > and bsize (the total number of bins) = 8, then each box type width = 32 degrees. After receiving the time domain histogram, The degree mapper integrates bin(1) to get the conversion function = (7), where cwrve(9)-〇' bln(1) is the time-domain histogram. The second box type has a positive JE' number and covers 1 to (bsize-Ι). The range of the actual application 'transfer function (four) v 咐ϋ multi-segment linear function, in the 'A figure / by the solid line indicates that 'every box type has - the corresponding straight line & and the mother - the slope of the straight line segment The function m(7)=(bin(1)/, where '丨 is a positive integer and covers the range of 1 to (bsize-Ι). According to the second embodiment, the rounded luminance level & is determined by the brightness mapper 16 200908727 150 according to The luminance level Γ is input and two functions m(/) are generated. The output brightness level ι is expressed as a mathematical equation as follows: I = (wrv# do; + ο// ίβί χηφ)), where z.do =fi〇〇ru/ww^), OetmodUAw^/O, is less than or Equal to the nearest integer, but the remainder. Since the human eye is less sensitive to chromaticity, the chromatic gain is generated in a box-type area, thereby avoiding excessive enhancement of color contrast. Thus, the luminance mapper 15 generates a chrominance gain for the chrominance components of the input pixel based on the conversion function cwrve (7) and the shell degree K of an input pixel (or an input image). The chrominance gain is expressed as a mathematical equation as follows: cg(〇=(3)rvw+u/(w/c^x(out)), where w(bsize_1)=1, ,· is an integer and covers 0 to (bsize-2 For example, when the input luminance level K is within the range of the 0th box type, the chrominance gain cg(〇) = cwrve[lj/(iWi/Mxl)); and when the input luminance level y is at the When the range of j box type is within, the chrominance gains c^(l)= palpitations 2)), and so on. Finally, the chroma mapper 620 applies the chroma gain to one of the input pixels to input a chroma component ς ' to obtain a corresponding output chroma component C„=C, X , where, must be less than or equal to The most recent integer. In summary, the present invention is an improvement of the histogram equalization method, which generates a one-to-one conversion function according to each image, without selecting a set of preset conversion letters 17 200908727 Disadvantages. And avoiding the adjustment of the drama α & average brightness shift is too large 隹 详 隹 隹 隹 隹 ^ ^ ^ ^ ^ ^ ^ ^ ^ 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体 具体It is to be understood that the scope of the present invention is not limited by the spirit of the present invention and the various modifications of the following patent application. 18 200908727 [Simple Description of the Drawings] FIG. 1 is a first embodiment of the present invention. Schematic diagram of the structure. Figure 2 is a comparison of two conversion functions. Figure 3 shows an example of a mixed-filter histogram and a user-defined histogram to generate a mixed histogram. Figures 4A to 4C show Three different Relationship between the ratio of the mixing parameter curve. "5 architecture diagram of the second graph according to the present embodiment of the present invention. f Figure 6 is a block diagram showing the architecture of the third embodiment of the present invention. Figure 7A shows an example of a time domain histogram and its corresponding conversion function. The figure shows a __ relationship diagram between the chroma run and the box type index according to the transfer function of Fig. 7A. [Main component symbol description]

6〇〇 dynamic contrast enhancement device 120 low pass filter 140 mixing unit 160 current page frame 100 '500 11 〇 straight square calculator 13 0 weight calculator 15 0 brightness mapper 170 regular device 22, 24 conversion function 32 user Custom Histogram 5 1 〇 Histogram Limiter 5 3 0 Scene Detector 620 Chroma Mapper 21 Brightness Histogram 23, 31 Filter Histogram 33 Mixed Histogram 5 20 Time Domain Filter 610 Local Histogram Calculator 19

Claims (1)

200908727 X. Patent application scope: A dynamic contrast enhancement device, comprising: a histogram S-time calculator for calculating a brightness histogram of a current page frame; a low-pass filter wave device connected to the histogram calculator, Performing a low-pass filtering process on the luminance histogram and generating a filtered histogram; see 5 units connected to the 6-Hai low-pass filter, according to a blending weight, to mix the filtered histogram with a user Straighten the square and generate a mixed histogram; A redundancy mapper is coupled to the mixing unit for generating a conversion function based on the mixed histogram and utilizing the conversion function to map the current page frame. 2. The dynamic contrast enhancement device as recited in claim 1, wherein: the normalizer is coupled to the low pass filter and the mixing unit to normalize the filtered histogram to a preset The total number of brightness levels; wherein the user-defined histogram is also normalized to the preset total number of brightness levels. 3. The dynamic contrast enhancement device as recited in claim 1 of the scope of the patent application further comprises: - a time domain filter, a wave clamp, respectively connected to the mixing unit and the brightness mapper, when a transition signal is disabled And the mixed histogram of the current page frame and the mixed histogram of the current page frame are used to directly output the mixed histogram of the current page frame when the transition signal is enabled; And a scene detector, in the video sequence, continuously comparing the brightness histogram of the upper frame and the brightness histogram of the current frame, when a scene conversion is detected by the debt, The transition signal, otherwise, when the scene transition cannot be smashed, the heart can disable the transition signal. For example, the application of the special rhyme@第i rhyme description of the dynamic pair (four) device, further includes: 20 200908727 - a chroma mapper connected to the brightness mapper for applying a chroma gain to one of the input chrominances of a pixel The component; the 4, medium 4 redundancy mapper further inputs the luminance component according to the conversion function and one of the pixels, and generates the chrominance gain in units of each box type. 5_If the scope of the patent is 帛! The dynamic contrast enhancement device described in the item further comprises: - a weight calculation ^ 'divided to the low i_wave device and the mixing unit, according to the filtered histogram and the user customized histogram to generate the The dynamic contrast enhancement device as recited in claim 5, wherein the weight calculation II is based on a first count value of the bin-box region in the filtered histogram, the user-defined histogram The second count value of one of the box zones is combined with a mixing parameter to generate the blending weight. 2 The dynamic contrast enhancement device described in Item 6 of the June patent scope, wherein the mixing parameter is generated according to the relationship between the preset mixing parameter and the ratio For example, the value of the sixth to fifth tenths of the patent application is selected from a blind user's custom histogram _ P large count value, p is the total number of type zones divided by three. The dynamic contrast enhancement device of the item, wherein one of the preset ranges is one of a maximum count value of one of the box-type zones to a positive integer and equal to the use Customized histogram box 21 200908727 1 〇. For example, the sixth comparison item of the application patent range is a dynamic contrast enhancement device with a preset value, wherein the r-^ configuration value, the preset range is the filter The histogram value has — 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于η·==围! The dynamic contrast enhancement device described in item t, wherein the t-th member 3 is the range-average value, the preset range is in the user-defined box type area- The Qth big count value to - the pth big 3 ρ is equal to the total number of the box type area of the user-defined histogram divided by 'P, Q is a positive integer and ρ> (^. 12· Μ please turn the standard (4) 1 item The documented contrast enhancement device further includes: a histogram restriction ☆ 'connected to the mixing unit to limit the mixing The maximum count value and the minimum count value of all the box types of the square map, wherein the blend weight value is equal to a first constant value. For example, the dynamic contrast strengthening device described in Item 1 of the claim 1 The graph calculator is based on the range of the box-type area, and generates a local brightness histogram, wherein the partial party histogram is composed of a plurality of box-shaped areas. 4. The dynamic contrast strengthening device described in the 13th patent touch, More includes: - Formal 11 'sub-job to the low-level wave and the mixing unit, used to set the count value of the all-box area of the range of the straight-line towel beyond the preset box type to be equal to - a second constant value, and normalizing the filtered histogram in the preset box type region to a total number of preset brightness levels minus the second constant value. 'The dynamic contrast enhancement as described in item 14 of the patent application scope The device, wherein the box type region exceeding the range of the preset box type region is a box type region of the crested histogram having the darkest brightness 22 200908727. 16. A dynamic contrast enhancement method comprising the steps of: calculating a current page Box Luma histogram; ^ luminance histogram execution - low pass filtering process to generate a ship histogram; according to the - blending weight, the chopping histogram and a user custom histogram are mixed to produce a mixed histogram; The mixed histogram is used to generate a conversion function; and the current page frame is mapped according to the conversion function. For example, the dynamic contrast enhancement method described in claim 16 of the patent scope, wherein the performing the low-pass filtering and wave processing steps is further The method comprises: normalizing the filtered 'wave histogram and the user-defined histogram to a preset total number of brightness levels. ~ 18. For example, please refer to the dynamic contrast enhancement method described in the patent scope ,16, wherein the execution The low-pass filtering processing step further includes: continuously comparing the brightness histogram of the upper page frame with the brightness histogram of the current page frame in a sequence, when a scene transition is detected, Enable a transition signal, otherwise, when the scene transition cannot be detected, the transition signal is disabled; and when the transition is disabled, the mix of the previous frame is mixed. FIG side of the current frame with the histogram of mixing, when the transition signal is enabled, the output of the direct mixing of the histogram of the current frame. • The dynamic contrast enhancement method as recited in claim 6 includes: inputting a luminance component according to the conversion function and one of the pixels, and generating a chrominance gain in units of each box type; The chrominance gain is applied to one of the input chrominance components of the pixel. 23 200908727 2〇. As described in the dynamic contrast enhancement method described in item 16 of the patent application scope, the step of performing the low-pass filtering process further comprises: 请 patent according to the t« wave histogram and the user custom straight 2·2 The dynamic contrast enhancement method described in item 20 of the scope is generated according to the second count value of the box-type area in the histogram of the wave, and any box type area in the user-defined histogram. A mixing parameter. 1 俚 and 22· 动态 动态 专利 专利 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态 动态One ratio. The dynamic contrast enhancement method described in Item No. 21 of the patent application scope of the 1st line is the one selected from a predetermined range, and the preset range is: = wave = graph of the - box In the type zone - the maximum count value to _ nth big count 2 is a single integer and is equal to the total number of box types of the filtered histogram divided by 3. V:; The dynamic contrast enhancement method described in the item 21, wherein the == is selected from one of a preset range, and the preset range is the one of the «customized histograms-box pets- The maximum count value is a p-large leaf value, P is a positive integer and is equal to the total divided by three. The box of the user's self-inflicted party map = the dynamic contrast enhancement method described in item 21 of the patent application scope, and the middle value = (four) - the preset range - the mean value, the preset range is continuous; In the -4 area - the third largest count value to the _ ν big count value, 2 ' Ν 该 该 滤波 滤波 滤波 滤波 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该</ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; In the box-box area - the Q-th large count value to - the P-th large count &quot; the total number of box-type areas in the user-defined histogram divided by 3, p, Q are positive integers and p &gt;Q. The dynamic contrast enhancement method described in Item 16 of the patent, wherein the mixing step further comprises: limiting a maximum count value and a minimum count value of all box types of the mixed histogram, wherein the blend weight is equal to one A constant value. For example, the dynamic contrast enhancement method described in item 16 of the scope of the patent application, the 丄丄/r々1_ 〆, 丁δ times 5 different steps further includes: generating a partial brightness histogram according to the preset box area range, Wherein, the local luminance histogram is composed of a plurality of box-shaped regions. 29. The dynamic contrast enhancement method as recited in claim 28, wherein the performing the low pass filtering processing step further comprises: Λ edge filtering histogram towel superitj all the box type regions of the preset box type area The count value is set equal to a second constant value; The filtered histogram in the preset box type region IS is normalized to - the total number of preset brightness levels minus the second constant value. 3〇 'The dynamic contrast enhancement method as described in claim 29, wherein the box type area exceeding the range of the preset box type area is the box-shaped area of the filtered direct sound. U take the calendar 25