TWI420491B - Adaptive feedback control method for field sequential lcd - Google Patents
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本發明係關於影像顯示，特別是指一種依據畫面內容即時調整得到影像色差最小值的背光色場，以改善色序法顯示器的色分離現象之適應性迴授控制方法。The invention relates to image display, in particular to an adaptive feedback control method for improving the color separation phenomenon of a color sequential display by adjusting a backlight color field which is obtained by instantly adjusting the minimum color difference of the image according to the screen content.
傳統液晶顯示器是利用彩色濾光片(Color Filter)達到全彩的效果，但其產生的光效率卻未如預期。近來發展的快速反應液晶，如光學補償彎曲排列(Optically Compensated Bend，OCB)模式，以及背光光源，如高效率的發光二極體(Light-Emitting Diode，LED)，係已實現色序法(Field Sequential Color，FSC)機制的液晶顯示器(Liquid Crystal Display，LCD)。藉由依序顯示主要的紅、藍、綠色場的速度快於人眼反應的時間解析度(Time Resolution)，即可不需使用彩色濾光片而達到全色彩的效果。結合發光二極體的背光與光學補償彎曲排列模式的液晶面板，預期色序法液晶顯示器(FSC-LCD)可以成為高光效率、低耗能以及低材料成本的彩色液晶顯示器。Conventional liquid crystal displays use a color filter to achieve full color, but the resulting light efficiency is not as expected. Recently developed fast-reaction liquid crystals, such as the Optically Compensated Bend (OCB) mode, and backlight sources, such as the high-efficiency Light-Emitting Diode (LED), have implemented the color-sequence method (Field). Sequential Color (FSC) mechanism of liquid crystal display (LCD). By sequentially displaying the main red, blue, and green fields faster than the time resolution of the human eye response, full color effects can be achieved without the use of color filters. In combination with a backlight of a light-emitting diode and a liquid crystal panel of an optically compensated curved alignment mode, it is expected that a color sequential liquid crystal display (FSC-LCD) can be a color liquid crystal display with high light efficiency, low power consumption, and low material cost.
然而，一般所知的色序法液晶顯示器最大的問題就是色分離(Color Break-Up，CBU)的問題。色分離CBU係由於在影像內的物體與觀察者眼睛之間的相對移動所產生，亦即在人眼掃動(saccade)期間，掃動的抑制(saccadic suppression)壓制了從人眼到腦部的信號。請參考圖1，係表示以一RGB色序法模擬出的一色分離影像，以三原色子場R、G、B模擬出的色分離影像M1中，可察覺色分離現象而導致降低整個影像的畫質。請再參考圖2，係表示習知色序法色彩影像顯示方法的示意圖，在觀察點隨時間移動的狀況下，通過色序法色彩顯示的圖樣可看出有色分離現象的問題。在色序法色彩顯示中以時間為序而顯現影像，其色彩順序為「RGB RGB RGB...」，其中R代表紅色次畫面、G代表綠色次畫面、B代表藍色次畫面。以白色影像W10為例，當要求顯現白色影像時，從移動觀察點看到的白色影像W10，會在白色影像W10的其中一邊緣W11(圖2左側)呈現藍色B以及藍色B與綠色G的組合，而在另一邊緣W12(圖2右側)則呈現紅色R以及紅色R與綠色G的組合，此即所謂的色分離現象。However, the most common problem with color-sequence liquid crystal displays is the problem of Color Break-Up (CBU). The color separation CBU is caused by the relative movement between the object in the image and the observer's eye, that is, during the human eye saccade, the saccadic suppression suppresses the human eye to the brain. signal of. Please refer to FIG. 1 , which shows a color separated image simulated by an RGB color sequence method. In the color separation image M1 simulated by the three primary color subfields R, G, and B, the color separation phenomenon can be perceived to cause the entire image to be reduced. quality. Referring to FIG. 2 again, it is a schematic diagram showing a conventional color-sequence color image display method. Under the condition that the observation point moves with time, the color separation phenomenon can be seen by the color-coded color display pattern. In the color-sequence color display, images are displayed in time order, and the color order is "RGB RGB RGB...", where R represents a red sub-picture, G represents a green sub-picture, and B represents a blue sub-picture. Taking the white image W10 as an example, when a white image is required to appear, the white image W10 seen from the moving observation point will appear blue B and blue B and green at one edge W11 (left side of FIG. 2) of the white image W10. The combination of G, and at the other edge W12 (on the right side of Fig. 2), presents a combination of red R and red R and green G, which is the so-called color separation phenomenon.
在色序法的應用上，美國第5,337,068號專利係揭露一種色序法顯示系統及形成影像的方法，以液晶裝置搭配紅、藍、綠三種顏色的背光，而三種顏色的背光分別發光，再由液晶裝置分別同時調整通過光量，構成三種顏色的子畫面，最後藉由紅、藍、綠三種顏色的子畫面組成一彩色畫面。而此種傳統的色序法系統架構及形成影像的方法所產生的色分離現象明顯，更易於為人所察覺。In the application of the color-sequence method, U.S. Patent No. 5,337,068 discloses a color-sequential display system and a method for forming an image, in which a liquid crystal device is combined with backlights of three colors of red, blue and green, and backlights of three colors respectively emit light, and then The liquid crystal device separately adjusts the amount of passing light to form a sub-picture of three colors, and finally forms a color picture by sub-pictures of three colors of red, blue and green. The color separation method produced by the conventional color-sequence system architecture and the image forming method is obvious and more easily perceived.
而美國第6,570,554號專利係揭露一種液晶顯示器，利用有規律變換連續三個畫面(Frame)的子色場，以解決傳統色序法液晶顯示器的色分離問題；當人眼以相同速度追跡運動物體，連續三個畫面影像的積分結果在人眼視網膜上，不會呈現出色分離現象。然而此種方法在當綠色色場頻率低於50赫茲(Hz)時，人眼將會感知閃爍現象(Flicker)，導致畫面品質不佳。U.S. Patent No. 6,570,554 discloses a liquid crystal display that uses a sub-color field that regularly transforms three consecutive frames to solve the color separation problem of a conventional color sequential liquid crystal display; when the human eye traces moving objects at the same speed The integration result of three consecutive images is on the retina of the human eye and does not exhibit excellent separation. However, in this method, when the green color field frequency is lower than 50 Hz, the human eye will perceive the flicker phenomenon (Flicker), resulting in poor picture quality.
再者，美國第7,057,668號專利係揭露一種解決色序法色分離現象的影像訊號處理方法，利用紅、藍、綠三種顏色的發光二極體，或者是另外再加上一白色的發光二極體，做為背光源的顯示器，當影像訊號輸入時轉換為YCrCb色彩系統；當顯示內容知色分離現象輕微時，用色序法來顯示影像畫面；而當顯示內容色分離現象嚴重時，則調整為將背光改為全亮之白光，即將紅、藍、綠三種顏色的發光二極體同時發光全亮，或只開啟白色的發光二極體，以抑制色分離現象的出現。然而，當背光為全亮時，仍需要彩色濾光片才能達到全彩影像的效果。Furthermore, U.S. Patent No. 7,057,668 discloses an image signal processing method for solving color separation color separation phenomenon, using red, blue and green light-emitting diodes, or additionally adding a white light-emitting diode. Body, as a backlight display, when the image signal input is converted to YCrCb color system; when the display content knows the color separation phenomenon is slight, the color sequence method is used to display the image frame; and when the display content color separation phenomenon is serious, then Adjusted to change the backlight to full-bright white light, that is, the red, blue, and green three-color light-emitting diodes are simultaneously illuminated, or only the white light-emitting diodes are turned on to suppress the occurrence of color separation. However, when the backlight is fully lit, a color filter is still needed to achieve the full color image.
另外，Jongseo Lee等人在IMID/IDMC’06發表一篇文章，主題為「Noble Measurement Method for Color Breakup Artifact in FPDs」，係利用CIE LUV色座標來分析色分離現象，並且定義在此座標中的色差(ΔE)為量化色分離的指標；但在此發表的文獻中，卻未提出其他新式方法以進行改善色分離現象。In addition, Jongseo Lee et al. published an article in IMID/IDMC'06 with the theme "Noble Measurement Method for Color Breakup Artifact in FPDs", which uses CIE LUV color coordinates to analyze color separation phenomena and is defined in this coordinate. Color difference (ΔE) is an indicator for quantifying color separation; however, in the literature published here, no other new methods have been proposed for improving color separation.
而在改善色分離問題上，美國第6,911,963號專利提出一種以色序法顯示方法以降低色分離的狀況，係顯示具有所有顯示色彩的輸入影像資訊(image information)之亮度資訊的時序，為了顯示輸入影像資訊，即同步地改變顯示色彩及亮度資訊，其中一頁面週期內以至少四個子場週期顯示一彩色影像，以及在至少一子場週期內的一圖片信號(picture signal)係為一非原色圖片信號(non-primary color picture signal)，且此非原色圖片信號係由包含有原色信號(primary color signal)的輸入圖片信號中的至少二原色信號所產生；而其處理方法是先將影像灰階rgb轉換成CIE1931XYZ色彩系統的刺激值(tristimulus value)XYZ之統計圖，再轉換成相對應的背光色刺激值XYZs，進而決定附加的子場顏色。In the improvement of the color separation problem, U.S. Patent No. 6,911,963 proposes a color-sequential display method to reduce the color separation, and displays the timing of the brightness information of the input image information having all display colors for display. Inputting image information, that is, changing display color and brightness information synchronously, wherein a color image is displayed in at least four subfield periods in one page period, and a picture signal in at least one subfield period is a non- a non-primary color picture signal, and the non-primary color picture signal is generated by at least two primary color signals in an input picture signal including a primary color signal; and the processing method is to first image The gray scale rgb is converted into a graph of the tristimulus value XYZ of the CIE1931XYZ color system, and then converted into a corresponding backlight color stimulus value XYZs, thereby determining the additional subfield color.
在使用上述方法時，必須先預設三個條件，包括：When using the above method, you must first preset three conditions, including:
(1)色分離容易發生在高亮度(Y值)信號位階(signal level)的高頻率部分；(1) Color separation is likely to occur at a high frequency portion of a high luminance (Y value) signal level;
(2)色分離容易發生在當X值的頻率大於Z值的頻率時；(2) color separation easily occurs when the frequency of the X value is greater than the frequency of the Z value;
(3)色分離容易發生在高Z值的部分，即X值及Y值都低的時候。(3) Color separation easily occurs in the portion of high Z value, that is, when both X value and Y value are low.
因此，符合條件(1)~(3)的每一信號位階所選出的色彩，即為附加的第四子場的色彩。然而，為了獲得第四子場的色彩必須先進行影像的統計值的分析，不但耗費計算的時間，也增加計算的容量。Therefore, the color selected for each signal level that satisfies the conditions (1) to (3) is the color of the additional fourth subfield. However, in order to obtain the color of the fourth subfield, it is necessary to first analyze the statistical value of the image, which not only consumes the calculation time but also increases the calculated capacity.
基於上述問題，發明人提出了一種新的色序法顯示器之適應性迴授控制方法，以克服現有技術的缺陷。Based on the above problems, the inventors have proposed a new adaptive feedback control method for a color sequential display to overcome the deficiencies of the prior art.
本發明目的在於提供一種根據輸入影像內容以同步更新液晶及背光灰階資訊，使得原本分布在各色場的顏色亮度能夠集中至單一色場，大幅度降低與輸入畫面每一畫素比較的加總色差值，來有效地抑制色分離現象。The object of the present invention is to provide a method for synchronously updating the liquid crystal and backlight gray scale information according to the input image content, so that the color brightness originally distributed in each color field can be concentrated to a single color field, and the total of each pixel compared with the input picture is greatly reduced. The color difference is used to effectively suppress the color separation phenomenon.
為了實現上述目的，本發明提供了一種色序法顯示器之適應性迴授控制方法，包含：重置步驟，係將一輸入影像的三原色場的灰階值轉換成一新的三原色場及一主色場(D-field)的灰階值；取樣步驟，針對該輸入影像的解析度進行一取樣區間的畫素取樣；迴授控制步驟，藉由在Lu'v' 色彩空間之一色分離色彩值以及該輸入影像色彩值進行各分色的畫素對畫素之加總以獲得一加總色差值，並對該加總色差值進行一位元數精確度的迴授控制，以獲得一最小的加總色差值；以及液晶/背光同步化步驟，依據該最小的加總色差值，對該輸入影像的一液晶訊號及一背光資訊進行同步化。In order to achieve the above object, the present invention provides an adaptive feedback control method for a color sequential display, comprising: a resetting step of converting a grayscale value of a three primary color field of an input image into a new three primary color field and a primary color a grayscale value of a field (D-field); a sampling step of performing pixel sampling of a sampling interval for the resolution of the input image; and a feedback control step of separating the color value by one color in the Lu'v' color space and The input image color value is subjected to pixel-to-pixel addition of each color separation to obtain a total color difference value, and the total color difference value is subjected to one-digit precision feedback control to obtain a The minimum summed color difference value; and the liquid crystal/backlight synchronization step, according to the minimum summed color difference value, synchronizing a liquid crystal signal and a backlight information of the input image.
較佳者，該取樣區間係為2×4畫素對畫素的區間。Preferably, the sampling interval is a range of 2×4 pixels to pixels.
較佳者，該加總色差值ΔE sum 係表示如下：Preferably, the summed color difference Δ E sum is expressed as follows:
其中，Lu'v' CBU 及Lu'v' 0 係分別表示在Lu'v' 色彩空間之該色分離色彩值以及該輸入影像色彩值。Among them, Lu'v' CBU and Lu'v' 0 represent the color separation color value and the input image color value in the Lu'v' color space, respectively.
較佳者，該位元數精確度係為3位元精確度。Preferably, the bit number accuracy is 3-bit precision.
較佳者，該重置步驟中的新的灰階值r’、g’、b’及d，係以下列式子表示：Preferably, the new grayscale values r', g', b' and d in the resetting step are expressed by the following equation:
r' =T -1 (T (r )-T (d )×BL r )； r' = T -1 ( T ( r )- T ( d ) × BL r );
g' =T -1 (T (g )-T (d )×BL g )； g' = T -1 ( T ( g )- T ( d ) × BL g );
b' =T -1 (T (b )-T (d )×BL b )； b' = T -1 ( T ( b )- T ( d ) × BL b );
其中，T (i )係表示從灰階i到液晶轉換值的轉換函數，而T -1 係為其反函數。Where T ( i ) represents the transfer function from the gray level i to the liquid crystal conversion value, and T -1 is the inverse function.
較佳者，該區間係產生有8組色分離加總色差值(CBUΔE sum )。Preferably, the interval produces eight sets of color separation plus total color difference values (CBU Δ E sum ).
另，本發明提供了一種色序法顯示器之適應性迴授控制方法，包含：，適用在劃分有若干區塊的輸入影像之一原圖，包含：取樣步驟，針對該原圖進行取樣，以獲得解析度小於該原圖的一取樣圖；重置步驟，將該輸入影像的三原色場的液晶訊號轉換成一新的三原色場及一主色場(D-field)液晶訊號的相對映的背光訊號；以及迴授運算步驟，係包括：時間延遲步驟，將新的三原色場液晶訊號延遲不同時間；相減步驟，將各色場所對映的液晶訊號相減並取絕對值；累加步驟，將該相減步驟中各色場總和累加起來，得到各自區塊的累加數值；其中，從該等區塊之起始區塊依序至最終區塊各自進行該取樣步驟、該重置步驟以及該迴授運算步驟，各自區塊運算獲得的累加數值取一最小累加數值即為該各自區塊的一背光訊號，並提供給下一區塊進行運算。In addition, the present invention provides an adaptive feedback control method for a color sequential display, comprising: applying to an original image of an input image divided into a plurality of blocks, comprising: a sampling step, sampling the original image, Obtaining a sampling pattern having a resolution smaller than the original image; and performing a resetting step of converting the liquid crystal signal of the three primary color fields of the input image into a new three primary color field and a corresponding backlight signal of a D-field liquid crystal signal And the feedback operation step includes: a time delay step of delaying the new three primary color field liquid crystal signals by different times; and a subtracting step, subtracting the liquid crystal signals of the respective color fields and taking an absolute value; and adding steps to the phase The sum of the color fields in the subtraction step is added up to obtain the accumulated values of the respective blocks; wherein the sampling step, the resetting step, and the feedback operation are performed from the starting block of the blocks to the final block. In step, the accumulated value obtained by the respective block operations takes a minimum accumulated value, which is a backlight signal of the respective block, and is provided to the next block for operation.
雖然本發明使用了幾個較佳實施例進行解釋，但是下列圖式及具體實施方式僅僅是本發明的較佳實施例；應說明的是，下面所揭示的具體實施方式僅僅是本發明的例子，並不表示本發明限於下列圖式及具體實施方式。While the invention has been described in terms of several preferred embodiments, the preferred embodiments of the present invention It is not intended that the invention be limited to the following drawings and embodiments.
在下文中，將具體地描述本發明之方法的實施例。Hereinafter, embodiments of the method of the present invention will be specifically described.
為了具體地抑制色分離，而將三原色子場R、G、B集中在主色場(dominated color field，D-field)D，如圖3所示。藉由重置色場(color fields)，即能增加原色的強度，及將此一顯明的原色場濃縮成單一混色場，藉以形成一可抑制色分離的影像M2。因此，相較於習知的三原色場，本發明會有較少的色分離及較少的色分離的可見度。In order to specifically suppress color separation, the three primary color subfields R, G, and B are concentrated in a dominant color field (D-field) D as shown in FIG. By resetting the color fields, the intensity of the primary colors can be increased, and the apparent primary color field can be concentrated into a single mixed color field to form an image M2 that can suppress color separation. Thus, the present invention has less color separation and less color separation visibility than conventional three primary color fields.
請參考圖4，係表示本發明迴授控制方法的方塊圖。為了達到上述的功效，本發明提供決定主色場(D-field)色彩及液晶/背光信號的迴授決定運算法則，以符合實際的應用，本發明包括取樣步驟S1、重置步驟S2以及迴授控制步驟S3，最後即進行液晶/背光同步化步驟S4，係可有效地獲得最佳背光值以降低色分離影響。Please refer to FIG. 4, which is a block diagram showing the feedback control method of the present invention. In order to achieve the above-mentioned effects, the present invention provides a feedback decision algorithm for determining a color field (D-field) color and a liquid crystal/backlight signal to conform to practical applications. The present invention includes a sampling step S1, a reset step S2, and a back The control step S3 is performed, and finally, the liquid crystal/backlight synchronization step S4 is performed, and the optimum backlight value can be effectively obtained to reduce the influence of color separation.
在輸入影像的解析度上決定了運算的複雜度，故必須針對選取的取樣區間進行比較，而在1×2到4×8畫素的取樣範圍中，比較同時可降低運算量且不影響影像解析度。In the resolution of the input image, the complexity of the operation is determined. Therefore, it is necessary to compare the selected sampling intervals, and in the sampling range of 1×2 to 4×8 pixels, the comparison can reduce the calculation amount without affecting the image. Resolution.
請參考圖5，係表示在比較錯誤率及影像取樣區間之間的關係圖。在圖中的2×2取樣區間(sampling period)即為具有1/4解析度的四個子影像(sub-image)，其餘依此類推。若是這四個子影像可以ΔE sum 運算而取代原影像，則四個不同背光狀態可以同時搭配，並縮短逼近最小ΔE sum 的步驟。當子影像及原影像的三原色RGB背光狀態之最小ΔE sum 不相等時，則會認為此子影像是一個誤差(error)。Please refer to FIG. 5, which is a diagram showing the relationship between the comparison error rate and the image sampling interval. The 2 × 2 sampling period in the figure is four sub-images with 1/4 resolution, and so on. If the four sub-images can replace the original image by Δ E sum operation, then four different backlight states can be matched at the same time, and the step of approaching the minimum Δ E sum is shortened. When the minimum Δ E sum of the three primary colors RGB backlight states of the sub-image and the original image are not equal, the sub-image is considered to be an error.
為了使後續迴授控制步驟S3中ΔE sum 計算，在實際應用中能降低計算量，則必須在主色場(D-field)上對彩色背光最佳化能予以簡化。圖5的比較影像係利用圖6所使用的五個影像(Tiffany、Space Robot、Airplane、Baboon及Lena，未圖示)進行子影像與誤差率之間的相互關係。誤差率係定義為對所有子影像的誤差數量的比率。在圖中可看出，在此五個影像中低於2×4畫素的取樣區間並無誤差產生。因此，可以藉由最小ΔE sum 的決定，而選擇2×4的取樣區間，以同時提供8組的三原色RGB背光。In order to calculate the Δ E sum in the subsequent feedback control step S3, the amount of calculation can be reduced in practical applications, and the color backlight optimization must be simplified in the main color field (D-field). The comparative image of Fig. 5 uses the five images (Tiffany, Space Robot, Airplane, Baboon, and Lena, not shown) used in Fig. 6 to perform the correlation between the sub-image and the error rate. The error rate is defined as the ratio of the number of errors to all sub-images. As can be seen in the figure, there is no error in the sampling interval of less than 2 × 4 pixels in the five images. Accordingly, by determining the minimum of Δ E sum, selecting a sampling interval of 2 × 4, to simultaneously provide the three primary colors RGB backlight 8 groups.
在主色與三元色(DRGB)色序液晶/背光灰階的重置係由影像內容決定。在主色場(D-field)中，三原色背光的灰階值係分別以BLr ，BLg ，BLb 所表示。在灰階與光強度之間的關係(γ曲線)係為線性關係。依據其背光資訊，在三原色場-紅(red，r)、綠(green，g)、藍(blue，b)及主色場(D-field，d)所形成新的液晶灰階值r’、g’、b’及d，係以下列式子表示：The reset of the main color and ternary color (DRGB) color sequence liquid crystal/backlight gray scale is determined by the image content. In the main color field (D-field), the grayscale values of the three primary color backlights are represented by BL r , BL g , BL b , respectively. The relationship between the gray scale and the light intensity (γ curve) is a linear relationship. According to the backlight information, a new liquid crystal gray scale value r' is formed in the three primary color fields - red (red), green (green), blue (blue, b) and the main color field (D-field, d). , g', b' and d, are expressed by the following formula:
式(1)：r' =T -1 (T (r )-T (d )×BL r )；Formula (1): r' = T -1 ( T ( r )- T ( d ) × BL r );
式(2)：g' =T -1 (T (g )-T (d )×BL g )；Formula (2): g' = T -1 ( T ( g )- T ( d ) × BL g );
式(3)：b' =T -1 (T (b )-T (d )×BL b )；Formula (3): b' = T -1 ( T ( b )- T ( d ) × BL b );
其中，T (i )係表示從灰階i到液晶轉換值(transmittance of LC)的轉換函數，而T -1 係為其反函數。在灰階值與小於一的轉換值之間的γ曲線係用以維持白平衡(white balance)。Where T ( i ) represents a transfer function from gray scale i to a liquid crystal conversion value (LC), and T -1 is an inverse function. The gamma curve between the grayscale value and the converted value less than one is used to maintain white balance.
主色場(D-field)彩色背光的決定對於降低色分離來說是非常重要的。如圖7所示，係表示主色場在三個不同背光灰階狀態下，對測試影像的模擬色分離影像。模擬的色分離影像可以由四個不同的平移彩色影像所組成。而其模擬所使用的軟體為MATLAB。而圖7A係表示習知主色場具有零-RGB值的色分離影像(稱為KRGB色場)，換句話說，此一影像即為以習知三原色場驅動的方法所獲得。相反地，如圖7B所示，習知在主色場提供一最高RGB值以顯示白色(稱為WRGB色場)所產生的影像。The decision of the primary color field (D-field) color backlight is very important to reduce color separation. As shown in FIG. 7, it is an analog color separation image of the test image of the main color field in three different backlight gray scale states. The simulated color separation image can be composed of four different panning color images. The software used for its simulation is MATLAB. 7A shows a color separation image (referred to as a KRGB color field) having a zero-RGB value in a conventional main color field. In other words, this image is obtained by a conventional three-primary field driving method. Conversely, as shown in FIG. 7B, it is conventional to provide a maximum RGB value in the primary color field to display an image produced by white (referred to as a WRGB color field).
而在圖7C中所示，係本發明之主色場(D-field)加總在色分離與原影像之間的色差(稱為DRGB色場)所產生的影像，而其加總方式是以分色的畫素對畫素(pixel by pixel)進行加總，加總色差值ΔE sum 係表示如下：As shown in FIG. 7C, the main color field (D-field) of the present invention adds up the image generated by the color difference between the color separation and the original image (referred to as the DRGB color field), and the sum is The pixels by pixel are summed by the pixels of the color separation, and the total color difference Δ E sum is expressed as follows:
其中，Lu'v' CBU 及Lu'v' 0 係分別為在Lu'v' 色彩空間之色分離(CBU)色彩值以及原影像色彩值。彩色背光係決定在色場影像亮度的分布。當主要的亮度強度集結在主色場(D-field)時，則三原色場的顏色會消失，也因此會有較少的色分離。可發現在圖7的三個影像中，DRGB色場的ΔE sum 所產生之影像的色分離現象係小於其他兩個色場(KRGB及WRGB)所產生之影像的色分離現象，亦即降低色分離現象的產生。Among them, Lu'v' CBU and Lu'v' 0 are the color separation (CBU) color values and the original image color values in the Lu'v' color space, respectively. The color backlight determines the distribution of brightness in the color field image. When the main brightness intensity is concentrated in the main color field (D-field), the color of the three primary color fields will disappear, and thus there will be less color separation. It can be found that in the three images of FIG. 7, the color separation phenomenon of the image generated by Δ E sum of the DRGB color field is smaller than that of the image generated by the other two color fields (KRGB and WRGB), that is, the image is reduced. The phenomenon of color separation.
在ΔE sum 計算的實際應用中，在主色場(D-field)上對彩色背光灰階值最佳化的簡化是必須的。背光的位元數越多者，即可包含越正確的最小ΔE sum ，如圖6所示。然而，增加背光的精確度，卻會使計算的負載以指數的速度遞增。請參考圖6，係表示五個測試影像在背光位元數與加總色差值ΔE sum 精確率之間的關係圖。相較於1位元的精確度中，在位元數大於3的時候，五個測試影像的ΔE sum 即已達到飽和。因此，3位元的精確度係設定為三原色RGB背光的變異係數(modified factor)，亦即以3位元數的背光進行迴授控制，即可獲得最佳的精確度，同時亦可減少計算量。In the practical application of the Δ E sum calculation, simplification of the color backlight gray scale value optimization on the main color field (D-field) is necessary. The more bits of the backlight, the more accurate the minimum Δ E sum can be included, as shown in Figure 6. However, increasing the accuracy of the backlight increases the calculated load at an exponential rate. Please refer to FIG. 6 , which is a graph showing the relationship between the number of backlight bits and the sum of the color difference values Δ E sum of the five test images. Compared with the accuracy of 1 bit, when the number of bits is greater than 3, the Δ E sum of the five test images has reached saturation. Therefore, the accuracy of the 3-bit is set to the modified factor of the RGB backlight of the three primary colors, that is, the feedback control of the 3-bit backlight is used to obtain the best accuracy, and the calculation can be reduced. the amount.
經過上述三個步驟的進行之後，亦即配合計算ΔE sum 的重置步驟S2，並以2×4取樣區間之取樣步驟及3位元精確度的迴授控制步驟S3，獲得最小ΔE sum ，最後再進行決定背光的液晶/背光同步化步驟S4，而同步化步驟係可藉由緩衝器進行時間延遲，以達到液晶與背光的同步效果。因此，當利用主色場(D-field)的方法所產生的彩色背光最佳化時，色分離現象即可以有效地被降低；更甚者，色分離影響係可藉由ΔE sum 值所決定。After the above three steps are performed, that is, the reset step S2 of calculating Δ E sum is performed, and the sampling step of the 2×4 sampling interval and the feedback control step S3 of the 3-bit precision are obtained to obtain the minimum Δ E sum Finally, the liquid crystal/backlight synchronization step S4 for determining the backlight is performed, and the synchronization step can be time delayed by the buffer to achieve the synchronization effect between the liquid crystal and the backlight. Therefore, when the color backlight generated by the method of the main color field (D-field) is optimized, the color separation phenomenon can be effectively reduced; moreover, the color separation effect can be obtained by the Δ E sum value. Decide.
請同時參考圖8A及圖8B，係分別表示決定液晶與彩色背光之灰階的詳細流程圖，以及以3位元精確度的逼近獲得最終背光值的示意圖。本實施例係包括一獲取加總色差值步驟及一訊號同步化步驟，以下即以一較詳細的實施例進行說明。Please refer to FIG. 8A and FIG. 8B simultaneously, which are respectively a detailed flowchart for determining the gray scale of the liquid crystal and the color backlight, and a schematic diagram of obtaining the final backlight value by approximating the 3-bit precision. This embodiment includes a step of acquiring a total color difference value and a signal synchronization step, which will be described below in a more detailed embodiment.
獲取加總色差值步驟包括：步驟SA1：將第n個頁面的影像轉換到Lu'v' 色彩空間；步驟SA2：以2×4取樣區間進行8組1位元背光及子影像的取樣，以包含色分離影像，並相較於原輸入影像，進行同步的8CBU-ΔE sum (8組色分離的ΔE sum )計算；步驟SA3：進行ΔE sum 的篩選及決定下一頁面的位元數；步驟SA4：鄰近具有二個最小ΔE sum 之1位元群組的彩色背光7組新的2位元群組，視為最小的ΔE sum ；其中，步驟SA3的篩選條件N如下：The step of obtaining the total color difference value includes: step SA1: converting the image of the nth page to the Lu'v' color space; step SA2: performing sampling of 8 sets of 1-bit backlights and sub-images in the 2×4 sampling interval, to contain the color separation image, and compared to the original input image, synchronizing 8CBU-Δ E sum (8 group color separation Δ E sum) calculation; step SA3: screening decision bit of the next page to be Δ E sum The number of elements; step SA4: a group of new 2-bit groups of color backlights adjacent to a group of 1 bit group having two minimum Δ E sums , regarded as the smallest Δ E sum ; wherein the screening condition N of step SA3 is as follows :
而步驟SA4中所有的8組彩色背光係藉由經過背光緩衝器(BL buffer)而使用在步驟SA2中，此一緩衝器係為用以在液晶與背光之間進行同步化的信號暫存器(signal register)。And all of the eight sets of color backlights in step SA4 are used in step SA2 by passing through a backlight buffer (BL buffer), which is a signal register for synchronizing between the liquid crystal and the backlight. (signal register).
在圖8A的另一部分即為訊號同步化步驟，係進行液晶訊號與背光訊號的同步化，如下所述：步驟SB1：將輸入影像的液晶信號經過頁面緩衝器(frame buffer)，獲得第n-1個頁面的液晶訊號；步驟SB2：將彩色背光的最小CBU-ΔE sum 經過背光緩衝器(BL buffer)，獲得第n-1個頁面的背光灰階值；步驟SB3：經由查表(Lookup Table，LUT)，使同步化的第n-1個頁面的液晶訊號及背光灰階值，產生新的液晶灰階值。In another part of FIG. 8A, the signal synchronization step is to synchronize the liquid crystal signal with the backlight signal, as follows: Step SB1: Pass the liquid crystal signal of the input image through the frame buffer to obtain the n-th. a liquid crystal page signal; step SB2: the minimum CBU-Δ E sum backlight passes through the color buffer backlight (BL buffer), to obtain the grayscale values of the backlight n-1 th page; step SB3: via a look-up table (the lookup Table, LUT), to make the liquid crystal signal and the backlight grayscale value of the n-1th page synchronized, and generate a new liquid crystal grayscale value.
在圖8B中，1位元及2位元群組的實心圓點，係表示二個最小的ΔE sum (BL1及BL2)群組，而空心圓點表示其他較大ΔE sum 群組。若是任一2位元群組的ΔE sum 等於或是小於1位元群組的ΔE sum 者，則在3位元群組的3位元逼近即在步驟SA3中進行。相反地，若是所有2位元群組的ΔE sum 大於1位元群組的ΔE sum 者，8組1位元的彩色背光則會在下一個頁面進行CBU-ΔE sum 的計算。而彩色背光的位元數精確度係藉由用以決定背光最佳化的迴授(feedback)所控制。In FIG. 8B, the solid dots of the 1-bit and 2-bit groups represent the two smallest Δ E sum (BL1 and BL2) groups, while the open circles represent other larger Δ E sum groups. If any of the group 2 yuan Δ E sum is equal to or less than 1 yuan Δ E sum by the group, i.e., the three yuan approximation in step SA3 in group 3 yuan. Conversely, if all Δ E sum by 2 yuan groups Δ E sum is greater than 1 yuan group, Group 1 8-bit color backlights if the next page is calculated CBU-Δ E sum of. The pixel accuracy of the color backlight is controlled by a feedback that determines the backlight optimization.
因此，藉由上述的迴授控制方法，可以降低色分離現象而使色分離產生達到最小，或者是能加以控制，進而減少計算量的負荷。Therefore, by the above-described feedback control method, it is possible to reduce the color separation phenomenon to minimize the generation of color separation, or to control it, thereby reducing the load of the calculation amount.
上述的方法(DRGB色場)係以單一畫面為單位進行重置步驟S2(請參考圖4)，且必須先進行色域的轉換，需耗費的計算時間較長，因此為了更進一步縮短計算時間，毋需進行色域轉換，並在單一畫面上劃分成數個顯示區塊，再針對各自顯示區塊進行重置步驟S2，以降低色分離現象而使色分離產生達到最小，其詳細步驟敘述如後。The above method (DRGB color field) performs the reset step S2 in units of a single screen (please refer to FIG. 4), and the color gamut conversion must be performed first, and the calculation time required is long, so that the calculation time is further shortened. The color gamut conversion is not required, and is divided into a plurality of display blocks on a single screen, and then the resetting step S2 is performed for each display block to reduce the color separation phenomenon to minimize the color separation, and the detailed steps are as follows. Rear.
請參考圖9，係表示本發明另一實施方法於重置步驟的方塊圖。本實施例(Fast DRGB色場)係將單一畫面P劃分成三個區塊(Block)做說明，即第一區塊B1、第二區塊B2、第三區塊B3，但並不以此為限；其中每一區塊的步驟包括：取樣步驟S5、重置步驟S6以及迴授控制步驟S7；其中代表原圖Po 紅、綠、藍三個液晶訊號，x 與y 為圖形座標，代表取樣圖Ps 紅、綠、藍三個液晶訊號，代表經DRGB演算步驟S6後的四個液晶訊號，表示與相減後取絕對值再依序累加的數值，且Block表示劃分的區塊數，number表示累加數值的組數。Please refer to FIG. 9, which is a block diagram showing another embodiment of the present invention in a resetting step. This embodiment (Fast DRGB color field) divides a single picture P into three blocks (Block) for description, that is, the first block B1, the second block B2, and the third block B3, but this is not The step of each block includes: a sampling step S5, a resetting step S6, and a feedback control step S7; Represents the original LCD P o red, green, blue three LCD signals, x and y are graphic coordinates, Represents three liquid crystal signals of P s red, green and blue. Represents the four liquid crystal signals after the DRGB calculation step S6, Express versus After subtraction, the absolute value is added to the value accumulated in order, and Block represents the number of divided blocks, and number represents the number of groups of accumulated values.
請同時參考圖10A及10B，係分別表示本發明另一實施例取樣步驟前的原圖及取樣後的取樣圖。首先，在取樣步驟S5中係假設在四個訊號中取一個訊號，因此取樣後的取樣圖Ps (圖10B)之解析度變得比原圖Po (圖10A)還小。Referring to FIG. 10A and FIG. 10B simultaneously, the original image and the sampled sample after sampling are respectively shown in another embodiment of the present invention. First, in the sampling step S5, it is assumed that one of the four signals is taken, so that the resolution of the sampled pattern P s (Fig. 10B) after sampling becomes smaller than the original picture P o (Fig. 10A).
在重置步驟S6中，DRGB的目的是要將原本是三個紅、綠、藍三個液晶訊號，分解成四個液晶訊號。新的紅、綠、藍三個液晶訊號會對映紅、綠、藍三個背光訊號，第四個主色場(D-field)d液晶訊號，會對映一個混光的紅、綠、藍三個背光訊號，主色場d液晶訊號會代表整張圖片的資訊，所以新的紅、綠、藍三個液晶訊號就會變小，使色分離抑制能夠有較好的結果。In the resetting step S6, the purpose of the DRGB is to decompose three liquid crystal signals, which are originally three red, green and blue, into four liquid crystal signals. The new three red, green and blue LCD signals will be red, green and blue, and the fourth main color field (D-field) d liquid crystal signal will be reflected in a mixed red, green, Blue three backlight signals, the main color field d liquid crystal signal will represent the information of the whole picture, so the new three red, green and blue liquid crystal signals will become smaller, so that the color separation suppression can have better results.
請參考圖11A、11B及11C，係分別表示本發明另一實施例在第一區塊、第二區塊及第三區塊的重置步驟取樣示意圖。背光訊號的選取標準是將大部分的資訊集中在主色場d，因此主色場d的亮度不會太低，所以背光灰階值從128開始到255結束，等分成五等分，有128、160、192、224、255的背光灰階值，然後有紅、藍、綠三種背光，共有125種背光組。將125種背光組，用125個小立方體代表(如圖11A所示)，然後取出最邊緣的八個小立方體，即表示有八組背光被選取，此八組背光值為(128，128，128)、(128，128，255)、(128，255，128)、(128，255，255)、(255，128，128)、(255，128，255)、(255，255，128)、(255，255，255)，為128跟255值的組合；之後再把第一區塊B1的液晶訊號根據這八組的背光值，代入影像訊號分解公式(式(1)~(4))算出主色場d的液晶訊號，在依序反推新的r’、g’、b’的液晶訊號。Please refer to FIG. 11A, FIG. 11B and FIG. 11C, which are schematic diagrams showing sampling steps of the first block, the second block and the third block in another embodiment of the present invention. The selection criterion of the backlight signal is to concentrate most of the information in the main color field d, so the brightness of the main color field d is not too low, so the backlight grayscale value starts from 128 to 255, and is equally divided into five equal parts, 128. The backlight grayscale values of 160, 192, 224, and 255 are followed by red, blue, and green backlights, and there are 125 backlight groups. The 125 backlight groups are represented by 125 small cubes (as shown in Fig. 11A), and then the eight small cubes at the outermost edge are taken out, that is, eight sets of backlights are selected, and the eight sets of backlight values are (128, 128, 128), (128, 128, 255), (128, 255, 128), (128, 255, 255), (255, 128, 128), (255, 128, 255), (255, 255, 128) , (255, 255, 255), is a combination of 128 and 255 values; after that, the liquid crystal signal of the first block B1 is substituted into the image signal decomposition formula according to the backlight values of the eight groups (equations (1) to (4) The liquid crystal signal of the main color field d is calculated, and the new liquid crystal signals of r', g', and b' are sequentially reversed.
請參考圖12，係表示本發明另一實施例於迴授運算步驟中各訊號時間延遲的示意圖。在迴授控制步驟S7中，將新的r’、g’、b’液晶訊號延遲不同時間(時間延遲步驟，步驟S71)，譬如將r’延遲一個時脈(Clock)、g’延遲二個時脈、b’延遲三個時脈，主色場d液晶訊號不延遲(如圖12所示)，當然亦可將r’延遲二個時脈、g’延遲一個時脈、b’延遲二個時脈，主色場d液晶訊號延遲三個時脈等，並不以此為限；因為是假設主色場d是第一個顯示，而r’、g’、b’延遲的意義是代表模擬色分離的訊號。最後依序時間，將各色場所對映的液晶訊號相減並取絕對值(相減步驟，步驟S72)，即K n =|T R' -T R |+|T G' -T G |+|T B' -T B |+K n -1 ，再總和累加(累加步驟，步驟S73)起來，即，得到第一區塊B1的累加數值K1 ~K8 。Please refer to FIG. 12, which is a schematic diagram showing the time delay of each signal in the feedback operation step according to another embodiment of the present invention. In the feedback control step S7, the new r', g', b' liquid crystal signals are delayed by different times (time delay step, step S71), for example, r' is delayed by one clock (Clock), g' is delayed by two. Clock, b' delay three clocks, the main color field d liquid crystal signal is not delayed (as shown in Figure 12), of course, can also delay r' two clocks, g' delay one clock, b' delay two The clock, the main color field d liquid crystal signal delays three clocks, etc., is not limited to this; because it is assumed that the main color field d is the first display, and the meaning of r', g', b' delay is Represents the signal of the analog color separation. Finally, in sequence, the liquid crystal signals of the respective color fields are subtracted and taken as absolute values (subtracting step, step S72), that is, K n =| T R' - T R |+| T G' - T G |+ | T B' - T B | + K n -1 , and then sum total (addition step, step S73), that is, The accumulated value K 1 ~K 8 of the first block B1 is obtained.
得到的最小的累加數值K，假設所對應的背光訊號組是(128，128，128)，以作為第一區塊B1的背光訊號，即表示此背光訊號在第一區塊B1所形成的新的影像，比較能抑制色分離，並提供給第二區塊B2的重置步驟S6進行處理。The minimum accumulated value K is obtained, and the corresponding backlight signal group is (128, 128, 128) as the backlight signal of the first block B1, that is, the new backlight signal is formed in the first block B1. The image is relatively suppressed from color separation and supplied to the resetting step S6 of the second block B2 for processing.
請再參考圖9B，由於在第一區塊B1已進行本發明迴授方法的處理，故將原125組背光(圖11A的小立體方塊)，往(128，128，128)那一塊立方體收斂，形成27個背光組，新的背光灰階值128、160、192，再取出27個背光組最外圍的八個點，背光組依序為(128，128，128)、(128，128，192)、(128，192，128)、(128，192，192)、(192，128，128)、(192，128，192)、(192，192，128)、(192，192，192)，然後再進行DRGB演算步驟S6以及迴授運算步驟S7，以獲得第二區塊B2的累加數值K1 ~K8 ，得到的最小的累加數值K，以作為第二區塊B2的背光訊號。Referring to FIG. 9B again, since the processing of the feedback method of the present invention has been performed in the first block B1, the original 125 sets of backlights (small solid squares in FIG. 11A) are converged toward the cube of (128, 128, 128). 27 backlight groups are formed, the new backlight gray scale values are 128, 160, 192, and then the outermost eight points of the 27 backlight groups are taken out, and the backlight groups are sequentially (128, 128, 128), (128, 128, 192), (128, 192, 128), (128, 192, 192), (192, 128, 128), (192, 128, 192), (192, 192, 128), (192, 192, 192) Then, the DRGB calculation step S6 and the feedback operation step S7 are performed to obtain the accumulated value K 1 to K 8 of the second block B2, and the obtained minimum accumulated value K is used as the backlight signal of the second block B2.
相同地，第三區塊B3亦根據第一區塊B1與第二區塊B2之方法進行處理，將27組背光收斂到8組背光，並獲得最小的累加數值，當作第三區塊B3的最佳背光訊號。Similarly, the third block B3 is also processed according to the method of the first block B1 and the second block B2, and the 27 sets of backlights are converged to 8 sets of backlights, and the smallest accumulated value is obtained, which is regarded as the third block B3. The best backlight signal.
綜而言之，在第一個實施例(DRGB色場)中，係將影像畫面用2×4的取樣週期，分別得到每一個區塊裡的各自八個子圖，給定每個子圖在不同的背光色場，因此每個不同的背光色場，就可以根據影像訊號分解公式，得出新的不同的子圖，再將新的子圖做模擬色分離，與原圖的訊號做差值總和累積，在經過相同的模式做三次的逼近，每次逼近都會選取不同的背光色場，最後，差值總和最小的即是最佳的背光色場。在計算中，係使用3-bit精確度用迴授的方式來逼近最佳解，由最佳的背光色場灰階BLr,BLg,和BLb，可得到對應的主色場液晶灰階d，同時，因為亮度的分量已經被移到主色場d，修正過的r’、g’、b’需要扣除主色場d的貢獻，此背光與液晶訊號同步的過程一併被考慮。In summary, in the first embodiment (DRGB color field), the image picture is divided into two sub-pictures in each block by using a 2×4 sampling period, given that each sub-picture is different. Backlight color field, so each different backlight color field, according to the image signal decomposition formula, can get a new different sub-picture, and then the new sub-picture is simulated color separation, and the original picture signal is the difference The sum is accumulated. After three approximations through the same mode, each backlight will select a different backlight color field. Finally, the sum of the differences is the best backlight color field. In the calculation, the 3-bit accuracy is used to approach the optimal solution by means of feedback. From the best backlight color field grayscales BLr, BLg, and BLb, the corresponding main color field liquid crystal gray scale d can be obtained. At the same time, since the component of the luminance has been moved to the main color field d, the corrected r', g', b' needs to be deducted from the contribution of the main color field d, and the process of synchronizing the backlight with the liquid crystal signal is also considered.
而第二個實施例(Fast DRGB色場)中，直接利用原圖與根據不同背光所新形成的色分離圖，直接做差值總和去做比較，因此在計算上會更加的快速；再利用多區塊，在這裡假設3個區塊為例，根據訊號給入第一區塊影像的時候，取樣然後利用不同的背光色場，將影像與色分離影像做差值總和，得到的最小差值總和即是第一區塊影像的最佳背光色場，在將第一段最佳背光色場帶入第二區塊影像，去做相同的運算得到第二區塊影像的最佳背光色場，在經過第三區塊的逼近，得出最後的最佳背光色場。因為運算是根據輸入的影像，所以可以做即時的運算，就不需要影像暫存器，在整張影像輸入完成的時候，即可得出最佳的背光色場。In the second embodiment (Fast DRGB color field), the original image and the color separation map newly formed according to different backlights are directly used, and the difference sum is directly compared to be compared, so the calculation is more rapid; reuse Multi-block, here assumes 3 blocks as an example. When the image is sent to the first block according to the signal, the sample is then sampled and the different backlight color fields are used to make the difference between the image and the color separated image, and the minimum difference is obtained. The sum of the values is the best backlit color field of the first block image, and the best backlight color of the second block image is obtained by taking the first best backlight color field into the second block image. The field, after approximating through the third block, yields the final best backlight color field. Because the operation is based on the input image, you can do real-time calculations, you don't need an image buffer, and you can get the best backlight color field when the entire image is input.
而根據圖9A及9B所示，係前一區塊會影響下一區塊，但可另藉由調控訊號寫入之方式，即可使各個區塊進行平行處理，再藉由每區塊自行收斂以選出各區塊的做小總色差值，達到每區塊有其各自獨立的最佳背光訊號；如此，在顯現方面，亦可與前述的方法達到相同效果。According to FIG. 9A and FIG. 9B, the previous block affects the next block, but the other blocks can be processed in parallel by means of the control signal writing, and then by each block. Convergence to select the small total color difference of each block, so that each block has its own independent optimal backlight signal; thus, in terms of appearance, the same effect can be achieved with the foregoing method.
另，為使本發明要補償主色場d的影像能夠更省電，相對映紅、綠、藍液晶訊號r、g、b的背光訊號可同時進行調光(DIMMING)，係依照下列的新的液晶訊號分解公式(式(6)~(9))，其跟原本的公式(式(1)~(4))不同的地方在於紅、綠、藍背光訊號r、g、b會根據其背光做調整，而原本的公式(式(1)~(4))係將紅、綠、藍背光訊號r、g、b的背光當作是全亮的狀況。In addition, in order to make the image of the main color field d of the invention more power-saving, the backlight signals of the red, green and blue liquid crystal signals r, g, b can be simultaneously DIMMING, according to the following new The liquid crystal signal decomposition formula (formula (6)~(9)) differs from the original formula (formulas (1) to (4)) in that the red, green, and blue backlight signals r, g, and b are based on The backlight is adjusted, and the original formula (Eqs. (1) to (4)) treats the backlights of the red, green, and blue backlight signals r, g, and b as fully lit.
本實施例(Fast DRGB色場)並未使用到整張圖像去做運算，而是劃分成數個區塊，因此不會有顏色集中在某一區塊的現象，在使用本發明兩個實施方法(DRGB及Fast DRGB)以比較相對的色分離，可以得知會有類似的色分離改善(請參考圖13)，因此可以說明本發明所提及的兩個實施方法均有相同的色分離改善結果。This embodiment (Fast DRGB color field) does not use the entire image to perform the operation, but is divided into several blocks, so there is no phenomenon that the color is concentrated in a certain block, and the two implementations of the present invention are used. The methods (DRGB and Fast DRGB) compare the relative color separations, and it can be seen that there will be similar color separation improvement (please refer to FIG. 13), so it can be explained that the two implementation methods mentioned in the present invention have the same color separation improvement. result.
雖然本發明以相關的較佳實施例進行解釋，但是這並不構成對本發明的限制。應說明的是，本領域的技術人員根據本發明的思想能夠構造出很多其他類似實施例，這些均在本發明的保護範圍之中。Although the present invention has been explained in connection with the preferred embodiments, it is not intended to limit the invention. It should be noted that many other similar embodiments can be constructed in accordance with the teachings of the present invention, which are within the scope of the present invention.
B1．．．第一區塊B1. . . First block
B2．．．第二區塊B2. . . Second block
B3．．．第三區塊B3. . . Third block
M1．．．色分離影像M1. . . Color separation image
M2．．．抑制色分離影像M2. . . Suppressed color separation image
W10．．．白色影像W10. . . White image
W11．．．邊緣W11. . . edge
W12．．．邊緣W12. . . edge
S1~S4．．．依據本發明一實施例(DRGB)適應性迴授控制方法的步驟S1~S4. . . Steps of adaptive feedback control method according to an embodiment (DRGB) of the present invention
SA1~SA4．．．獲取加總色差值步驟SA1~SA4. . . Get the total color difference step
SB1~SB3．．．訊號同步化步驟SB1~SB3. . . Signal synchronization step
S5~S7．．．依據本發明另一實施例(Fast DRGB)適應性迴授控制方法的步驟S5~S7. . . Steps of adaptive feedback control method according to another embodiment (Fast DRGB) of the present invention
S71~S73．．．迴授運算步驟之子步驟S71~S73. . . Substeps of the feedback operation step
圖1 係表示以一RGB色序法模擬出的一色分離影像。Figure 1 shows a one-color separated image simulated by an RGB color sequence method.
圖2 係表示習知色序法色彩影像顯示方法的示意圖。2 is a schematic view showing a conventional color sequential color image display method.
圖3 係表示以本發明之主色場(D-field)色序法模擬出的一色分離影像。Fig. 3 is a view showing a one-color separated image simulated by the D-field color sequential method of the present invention.
圖4 係表示本發明迴授控制方法的方塊圖。Figure 4 is a block diagram showing the feedback control method of the present invention.
圖5 係表示在比較錯誤率及影像取樣區間之間的關係圖。Figure 5 is a graph showing the relationship between the comparison error rate and the image sampling interval.
圖6 係表示五個測試影像在背光位元數與加總色差值ΔE sum 精確率之間的關係圖。Figure 6 is a graph showing the relationship between the number of backlight bits and the total color difference Δ E sum accuracy for five test images.
圖7A 係表示習知主色場具有零-RGB值的色分離影像(稱為KRGB色場)。Fig. 7A shows a color separation image (referred to as a KRGB color field) having a conventional primary color field having a zero-RGB value.
圖7B 係表示習知在主色場提供一最高RGB值以顯示白色(稱為WRGB色場)所產生的影像。Figure 7B shows an image produced by the conventional color field providing a maximum RGB value to display white (referred to as WRGB color field).
圖7C 係表示本發明加總在色分離與原影像之間的色差(稱為DRGB色場)所產生的影像。Fig. 7C shows an image produced by the present invention in which the color difference (referred to as the DRGB color field) between the color separation and the original image is added.
圖8A 係表示決定液晶與彩色背光之灰階的詳細流程圖。Fig. 8A is a detailed flow chart showing the gray scale of the liquid crystal and the color backlight.
圖8B 係表示以3位元精確度的逼近獲得最終背光值的示意圖。Figure 8B is a schematic diagram showing the final backlight value obtained by approximating the 3-bit accuracy.
圖9 係表示本發明另一實施方法於重置步驟的方塊圖。Figure 9 is a block diagram showing another embodiment of the present invention in a resetting step.
圖10A 係表示本發明另一實施例取樣步驟前的原圖。Figure 10A is a view showing the original image before the sampling step of another embodiment of the present invention.
圖10B 係表示本發明另一實施例取樣步驟取樣後的取樣圖。Figure 10B is a sampling diagram showing sampling after sampling steps in another embodiment of the present invention.
圖11A 係表示本發明另一實施例在第一區塊的重置步驟取樣示意圖。Figure 11A is a diagram showing the sampling of the resetting step of the first block in another embodiment of the present invention.
圖11B 係表示本發明另一實施例在第二區塊的重置步驟取樣示意圖。Figure 11B is a schematic diagram showing the sampling of the resetting step of the second block in another embodiment of the present invention.
圖11C 係表示本發明另一實施例在第三區塊的重置步驟取樣示意圖。Figure 11C is a schematic diagram showing the sampling of the resetting step of the third block in another embodiment of the present invention.
圖12 係表示本發明另一實施例於迴授運算步驟中各訊號時間延遲的示意圖。Figure 12 is a diagram showing the time delay of each signal in the feedback operation step in another embodiment of the present invention.
圖13 係表示本發明二實施例(DRGB及Fast DRGB)色分離抑制曲線圖。Figure 13 is a graph showing the color separation suppression curves of the second embodiment (DRGB and Fast DRGB) of the present invention.
S1．．．取樣步驟S1. . . Sampling step
S2．．．重置步驟S2. . . Reset step
S3．．．迴授控制步驟S3. . . Feedback control step
S4．．．液晶/背光同步化步驟S4. . . LCD/backlight synchronization step
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| JP2008268323A (en) * | 2007-04-17 | 2008-11-06 | Seiko Epson Corp | Display device, driving method of display device, and electronic equipment |
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| Publication number | Publication date |
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| TW201025273A (en) | 2010-07-01 |
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