TW558899B

TW558899B - Methods and systems for improving display resolution in images using sub-pixel sampling and visual error filtering

Info

Publication number: TW558899B
Application number: TW90130880A
Authority: TW
Inventors: Scott J Daly; Rajesh Reddy K Kovvuri
Original assignee: Sharp Kk
Priority date: 2000-12-12
Filing date: 2001-12-12
Publication date: 2003-10-21
Also published as: EP1350221A2; WO2002048960A2; CN1489760A; WO2002048960A3; CN1267882C; JP2004524729A

Abstract

The present invention provides a method and an apparatus for converting a color image of a higher-resolution to an image of a lower-resolution. With the method of the present invention, based on characteristics of spatial frequency responses of the human visual system, a lower-resolution image (116) is formed by separating a higher-resolution image (72) into a luminance channel (76) and chrominance channels (98 and 100) so as to carry out suitable sampling and filtering for each of the luminance channel (76) and the chrominance channels (98 and 100), then by combing the luminance channel (86) and the chrominance channels (111 and 114) after the sampling. As to the chrominance channels (98 and 100), traditional sub-sampling (101 and 103) is carried out to avoid chromatic aliasing, while sub-pixel sampling (80) is performed for the luminance channel (76) to improve resolution of luminance component.

Description

558899 A7 B7 五、發明説明（1 ) 發明領域本發明具體實施例相關於使用較低解析度顯示高解析度影像之領域，其中顯示器使用三基色排列來顯示R、G和B 或影像的其他分量（component)。例如，這種三基色排列苇見於直觀式LCD顯示器’並且在此類排列中，單一像素係由三個並列（side-by-side)次像素所組成。每個次像素均只控制三原色（即，紅（R)、綠（G)和藍（B))的一色，接著，僅被數位影像表示的三原色控制。高解析度影像可在記憶體中取得，或直接從一演算法（向量圖形、某些字形設計及電腦圖形）取得。本專利申請主題相關於2〇00年12月12日提出之Scott Daly發明之美國專利申請標題「Methods and Systems for Improving Display Resolution using Sub-Pixel Sampling and Visual Error Compensation」，並且授予美國專利申請案號09/735,454。該份美國專利申請以提及方式併入本文中。本專利申請主題也相關於2000年12月12日提出之Rajesh Reddy K Kovvuri與Scott Daly發明之美國專利申請標題「Methods and Systems for Improving Display Resolution in achromatic Images using Sub-Pixel Sampling and Visual Error Filtering」，並且授予美國專利申請案號〇9/735,425 。該份美國專利申請以提及方式併入本文中。發明背景最常使用之在較低解析度顯示器上顯示高解析度影像領域的方法為，將高解析度影像4的像素2向下取樣成為低解 -5- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 裝訂558899 A7 B7 V. Description of the invention (1) Field of the invention The specific embodiments of the present invention relate to the field of displaying high-resolution images using lower resolutions, where the display uses three primary color arrangements to display R, G, and B or other components of the image (Component). For example, this three-primary-color arrangement is found in intuitive LCD displays' and in this arrangement, a single pixel is composed of three side-by-side sub-pixels. Each sub-pixel controls only one of the three primary colors (ie, red (R), green (G), and blue (B)), and is then controlled by only the three primary colors represented by the digital image. High-resolution images can be obtained in memory or directly from an algorithm (vector graphics, certain glyph designs, and computer graphics). The subject matter of this patent application is related to the U.S. patent application title "Methods and Systems for Improving Display Resolution using Sub-Pixel Sampling and Visual Error Compensation" invented by Scott Daly on December 12, 2000, and is granted a U.S. patent application number 09 / 735,454. This U.S. patent application is incorporated herein by reference. The subject matter of this patent application is also related to the US patent application titled "Methods and Systems for Improving Display Resolution in achromatic Images using Sub-Pixel Sampling and Visual Error Filtering" invented by Rajesh Reddy K Kovvuri and Scott Daly on December 12, 2000, And granted U.S. Patent Application No. 09 / 735,425. This U.S. patent application is incorporated herein by reference. BACKGROUND OF THE INVENTION The method most commonly used in the field of displaying high-resolution images on lower-resolution displays is to down-sample pixel 2 of the high-resolution image 4 to a low resolution. -5- This paper scale applies the Chinese National Standard (CNS ) A4 size (210 X 297 mm) binding

558899 A7 _ B7 五、發明説明（2 ) 析度顯示器6的解析度，如圖1所示。然後，每個向下取樣彩色像素8的R，G，B值被映射至每個顯示像素16的R，G ，B元素10、12和14。一個顯示像素的R，G，B元素10、12 和14也稱為子像素。因為顯示裝置不允許重疊色彩元素，所以次像素只能呈現R、G或B三色中的一色，但是，色彩的幅度（amplitude)可在整個灰階範圍（例如，〇至255)改變。次像素通常具有1 : 3寬高比（寬：高），所以產生的像素 16是正方形。次取樣/映射技術不會考慮顯示器的R、〇和 B次像素被空間移位的事實；事實上，這些技術假設會以如圖1所示之高解析度影像中相同的方式重疊這些次像素。這種類型的取樣可稱為次取樣或傳統次取樣。高解析度影像4的像素被呈現為三個稍微偏移的堆疊正方形8，以指示相同空間位置（即，像素）之rgb值的相關性。一個顯示像素16係由R、G和B次像素10、12和14所組成，並且圖1中使用黑線將之標示為較低解析度三基色顯示器6的一部份。其他的顯示像素係以淡色虛線標示。在這個實例中，高解析度影像具有比顯示器高3倍以上的解析度（水平及垂直維）。由於這個直接次取樣技術會導致混淆后生現象（aliasing artifacts)，所以會使用各種方法，如平均鄰接未取樣像素與取樣像素。請注意，當次取樣時平均鄰接元素的常見技術數學上等於使用矩形（rect)濾波器預先;慮波高解析度影像。再者，請注意，選取不同於最左邊像素（如圖所示）的像素可被視為只影響相位的預先濾波。因此，與防止混淆（aliasing)相關的大部份處理均被 -6 _ 本紙張尺度適用中國國家標準(CNS) A4規格(210X 297公釐) " 558899 A7 B7 五、發明説明（3 ) 視為對高解析度影像的濾波作業，即使核心只適用於被取樣像素位置。如本說明書及申請專利範圍中的定義，消色差 (achromatic)影像沒有可見的色彩變化。當影像只包括一層或色彩通道時，或當影像具有多層或色彩通遒，但是每層色彩層完全一樣藉此產生單一色彩影像時，則會發生消色差（achromatic)狀況。應明白，前面提及的技術不利用可能的顯示解析度。如需這個領域的背景資訊，請參閱R· Fiegenbiatt (1989) 「Full color imaging on amplitude color mosaic displays」 Proc. SPIE V· 1075，199-205 ;以及 J· Kranz and L. Silverstein (1990)「Color matrix display image quality : The effects of luminance and spatial sampling」，這些文獻（29-32) 以提及方式併入本文中。例如，在圖1所示的顯示器中，當顯示像素16解析度是高解析度影像（來源影像）4的1/3時，則次像素1〇、12和14 的解析度等於來源影像的解析度（水平維）。如果顯示器僅供色盲者使用，則可能利用次像素的空間位置。圖2顯示這種做法，其中顯示器的r、G*B次像素1〇、12和14係由高解析度影像之不同像素Π、13和15的對應色彩取得。這允终水平解析度成為次像素解析度，其是顯示像素解析度的3倍。但疋’對於不是色盲的顯示器觀看者而言又如何？即，大部份的觀看者。對顯示器設計人員而言非常幸運，甚至本紙張尺度適用中g g豕標準(CNS) μ規格(⑽X撕公爱) A7 B7 五、發明説明（4 ) 具有理想色彩5視力的觀看者都是最高空間頻率的色盲。如圖3所不，圖中顯不人類視力系統的理想化空間頻率響應。如圖所7JT，売度1 7代表檢視影像的消色差對比度，以及色度19表示色彩内I，視力系統將之處理為從紅色調變成綠色以及從藍色調變成黃色的等亮度（is〇luminant)調變。視訊色差信號的R-G和B-Y略約約為這些調變。對於大部份的觀看者而I，色度頻率響應頻寬是亮度頻率響應頻寬的1/2。有時候，藍色轉黃色調整響應的頻寬低於亮度約1/3 以下。如圖2所示，包括將色彩元素從不同影像像素映射至顯示像素二基色之次像素的取樣可稱為次像素取樣。请參考圖4 ’在顯示器的水平方向中，頻率範圍係介於顯示像素16的Nyquist(顯示像素=三基色像素，假設三基色Nyquist是每三基色像素〇·5循環（cycle))與次像素1〇、12 和14的Nyquist頻率（每次像素0.5循環= ι·5循環/三基色像素 (cycles/triad pixels))之間。圖4所示的矩形區2〇標示這個頻率範圍。圖中淡點虛曲線22標示使用寬度等於顯示取樣空間之rect函數捲積（convolving)高解析度影像所產生的 sine函數。當顯示器是LCD時，這是用以模型化顯示器 MIF(modulation transfer function;調變轉換函數）所採用的最常見做法。圖中虛曲線24標示使用等於次像素空間之rect捲積 (convolving)高解析度來源影像所產生的sine函數，其具有較高頻率。這是因為顯示器認為次像素是一維中的rect所 -8- 本紙張尺度適用中國國家標準(CNS) A4規格(210X 297公釐) 558899558899 A7 _ B7 V. Description of the invention (2) The resolution of the resolution display 6 is shown in FIG. 1. Then, the R, G, and B values of each down-sampled color pixel 8 are mapped to the R, G, and B elements 10, 12, and 14 of each display pixel 16. The R, G, and B elements 10, 12, and 14 of a display pixel are also called sub-pixels. Because the display device does not allow overlapping color elements, the sub-pixel can only represent one of the three colors of R, G, or B. However, the amplitude of the color can be changed throughout the grayscale range (for example, 0 to 255). The sub-pixels usually have a 1: 1 aspect ratio (width: height), so the resulting pixel 16 is a square. Sub-sampling / mapping techniques do not take into account the fact that the R, 0, and B sub-pixels of the display are spatially shifted; in fact, these techniques assume that these sub-pixels are overlapped in the same way as in the high-resolution image shown in Figure 1. . This type of sampling can be referred to as subsampling or traditional subsampling. The pixels of the high-resolution image 4 are presented as three slightly offset stacked squares 8 to indicate the correlation of rgb values at the same spatial location (ie, pixels). A display pixel 16 is composed of R, G, and B sub-pixels 10, 12, and 14, and a black line is used as a part of the lower-resolution tri-primary display 6 in FIG. The other display pixels are indicated by light-colored dotted lines. In this example, the high-resolution image has a resolution (horizontal and vertical dimensions) that is more than 3 times higher than that of the display. Since this direct subsampling technique can cause aliasing artifacts, various methods are used, such as averaging adjacent unsampled pixels and sampled pixels. Note that the common technique of averaging adjacent elements when subsampling is mathematically equivalent to using a rectangular (rect) filter in advance; consider wave high-resolution images. Also, please note that selecting pixels other than the leftmost pixel (as shown) can be considered as pre-filtering that only affects the phase. Therefore, most of the treatments related to the prevention of aliasing are handled by -6 _ This paper size applies the Chinese National Standard (CNS) A4 specification (210X 297 mm) " 558899 A7 B7 V. Description of the invention (3) For filtering operations on high-resolution images, even if the kernel is only applicable to the sampled pixel positions. As defined in this specification and the scope of patent applications, achromatic images have no visible color change. Achromatic conditions occur when the image contains only one layer or color channel, or when the image has multiple layers or color channels, but each color layer is exactly the same to produce a single color image. It should be understood that the aforementioned techniques do not take advantage of possible display resolutions. For background information in this area, see R. Fiegenbiatt (1989) "Full color imaging on amplitude color mosaic displays" Proc. SPIE V · 1075, 199-205; and J. Kranz and L. Silverstein (1990) "Color matrix display image quality: The effects of luminance and spatial sampling ", these documents (29-32) are incorporated herein by reference. For example, in the display shown in FIG. 1, when the resolution of the display pixel 16 is 1/3 of the high-resolution image (source image) 4, the resolution of the sub-pixels 10, 12 and 14 is equal to the resolution of the source image. Degree (horizontal dimension). If the display is intended for color blind people only, the spatial position of the sub-pixels may be used. Figure 2 shows this approach, in which the r, G * B sub-pixels 10, 12 and 14 of the display are obtained from the corresponding colors of the different pixels Π, 13 and 15 of the high-resolution image. This allows the final horizontal resolution to become sub-pixel resolution, which is three times the display pixel resolution. But what about 疋 ’for display viewers who are not colorblind? That is, most viewers. Fortunately for display designers, even this paper size is applicable to the gg 豕 standard (CNS) μ specification (⑽X tear public love) A7 B7 V. Description of the invention (4) Viewers with ideal color 5 vision are the highest space Color blindness in frequency. As shown in Figure 3, the figure shows the idealized spatial frequency response of the human vision system. As shown in the figure 7JT, the degree 1 7 represents the achromatic contrast of the viewing image, and the chromaticity 19 represents the I in the color. The vision system processes it to equal brightness from red to green and blue to yellow. ) Modulation. The R-G and B-Y of the video color difference signal are approximately about these modulations. For most viewers, I, the chrominance frequency response bandwidth is 1/2 of the luminance frequency response bandwidth. Sometimes the bandwidth of the blue-to-yellow adjustment response is lower than about 1/3 of the brightness. As shown in FIG. 2, the sampling including mapping the color elements from different image pixels to the sub-pixels of the two primary colors of the display pixel can be referred to as sub-pixel sampling. Please refer to FIG. 4 'In the horizontal direction of the display, the frequency range is between Nyquist (display pixel = three primary color pixels of display pixel 16), assuming that three primary color Nyquist is 0.5 cycles and three sub-pixels Nyquist frequencies of 10, 12, and 14 (0.5 cycles per pixel = ι · 5 cycles / triad pixels). The rectangular area 20 shown in Fig. 4 indicates this frequency range. The light-dotted dotted curve 22 in the figure indicates the sine function generated by convolving a high-resolution image using a rect function with a width equal to the display sampling space. When the display is an LCD, this is the most common approach used to model a display MIF (modulation transfer function). The dashed curve 24 in the figure indicates a sine function generated by using a rect convolving high-resolution source image equal to sub-pixel space, which has a higher frequency. This is because the display considers the sub-pixel to be a rect in a one-dimensional dimension.

,致的限。如矩形區2〇所示，次像素可顯示亮度資訊，但疋不把顯不色度資訊。事實上，在這個區塊中的任何色度資訊均被混淆。因Λ，在這個區塊中，藉由允許色度混淆 ’：可達成高於三基色(即，顯示)像素允許的較高頻率亮度貝訊。這是藉由使用次像素取樣所提供的「優點」區塊。針對孚形顯示應用，通常會預先處理黑&白字形，如圖 5所不。標準預先處理包括微量壓縮,這表示將位於像素中心的字形筆劃集中，即，字形筆劃特有的相移 (phase shift)。I後通常接著低通濾波，也稱為灰階抗混淆（greyscale antialiasing)。裝訂Due to the limit. As shown in the rectangular area 20, the sub-pixels can display brightness information, but do not display color information. In fact, any chroma information in this block is obfuscated. Because Λ, in this block, by allowing chrominance obfuscation ': a higher frequency luminance signal than that allowed by the three primary color (i.e., display) pixels can be achieved. This is a "benefit" block provided by using sub-pixel sampling. For fusiform display applications, black & white glyphs are usually processed in advance, as shown in Figure 5. Standard preprocessing includes micro-compression, which means that the glyph strokes centered on the pixel are concentrated, that is, the phase shift specific to the glyph strokes. I is usually followed by low-pass filtering, also known as greyscale antialiasing. Binding

圖3顯示理想化的視覺頻率響應 response ; CSF)。實際上，視覺頻率響應具有有限下降的斜率，如圖6A所示。亮度CSF 30已從cy/deg單元映射至顯示像素域（假設1280像素檢視距離）。如圖所示，實線3〇具有接近1.5循環/像素（Cy/pixei ;顯示像素）的最大頻率，並且通頻段形狀具有接近0.2循環/像素三基色（cy/pixehriad) 的波峰。虛線標示R: G CSF 32，這是具有接近〇·5循環/ 像素（cy/pixel)最大頻率的低頻段。點虛lpf曲線標示β : Y調變CSF 34，其最大頻率類似於r: g CSF，但是具有較低的最大響應。色度CSF 32和34與亮度CSF 3 0之截止頻率之間的範圍是允許色度混淆的區塊，以改良亮度頻寬。圖6 A還以1 /f函數顯示理想化影像功率譜3 6，如圖中斜率為-1的直線所示（由於圖式使用log軸）。這個頻譖以取樣頻率重複。這些重複呈_現水平方向的像素38和次像素40取 -9- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A7 B7 ) 五、發明説明（6 樣率。於低頻率38發生的重複頻譜係因像素取樣所導致，而於高頻率40發生的重複頻譜係因次像素取樣所導致。請注意，由於在log頻率軸上標繪，所以形狀會改變。這些延伸至低於Nyquist較低頻率之重複頻譜的頻率被稱為混淆（aliasing)。最左邊是因像素取樣率所導致的色度混淆38 ’而因為允度混淆4 0與較高次像素取樣率有關，所以會發生在較高頻率。在圖6 A中，來源頻譜尚未經過預先濾波處理。於是，由於像素取樣所導致的混淆（即，色度混淆）延伸至非常低的頻率35。因此，即使色度CSF具有於低亮度CSF的頻寬，色彩后生現象仍然可見（視顯示器的雜訊及對比度而定）。在圖6B中，來源功率譜已經過預先濾波（等於三個來源影像像素的rect函數），如圖4的點虛線22所示，並且可發現到它會影響通過0_5循環/像素（cy/pixei)的基頻段頻譜42 ，導致它具有比-1更陡峭的斜率，如44所標示。重複還顯示這個預先濾波的效應。甚至使用這個濾波，我們可發現在低於色度CSF 32a和34a之截止頻率的頻率46會發生某種色度混淆（位於較低頻率的重複頻譜）^因此，可發現到簡易型亮度預先濾波具有一段難以去除色度混淆的困難時間 ’而無法去除通過0·5循環/像素（cy/pixel)(即，「優點」區塊）的所有亮度頻率。由於我們依賴視覺系統頻寬差當作亮度或色度函數，以在「優點區塊」20中提供亮度頻寬提高，一項可能性是依據視覺系統模型設計預先濾波處理，相關說明請參考c -10- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A7 B7 五、發明説明（7 )Figure 3 shows the idealized visual frequency response (CSF). In fact, the visual frequency response has a limited decreasing slope, as shown in Figure 6A. The brightness CSF 30 has been mapped from the cy / deg unit to the display pixel domain (assuming a viewing distance of 1280 pixels). As shown in the figure, the solid line 30 has a maximum frequency close to 1.5 cycles / pixel (Cy / pixei; display pixel), and the passband shape has a peak close to 0.2 cycle / pixel three primary colors (cy / pixehriad). The dotted line indicates R: G CSF 32, which is a low frequency band with a maximum frequency close to 0.5 cycles / pixel (cy / pixel). The dotted virtual lpf curve indicates β: Y modulation CSF 34, whose maximum frequency is similar to r: g CSF, but with a lower maximum response. The range between the chrominance CSF 32 and 34 and the cutoff frequency of the luminance CSF 30 is a block that allows chrominance confusion to improve the luminance bandwidth. Figure 6A also shows the idealized image power spectrum 36 as a 1 / f function, as shown by a straight line with a slope of -1 (due to the use of the log axis in the figure). This frequency repeats at the sampling frequency. The pixels 38 and sub-pixels 40 which are repeatedly present in the horizontal direction are taken as -9.-This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 558899 A7 B7. 5. Description of the invention (6 sample rate. The repetitive spectrum that occurs at low frequency 38 is due to pixel sampling, and the repetitive spectrum that occurs at high frequency 40 is due to sub-pixel sampling. Please note that the shape changes due to plotting on the log frequency axis. These The frequency of the repetitive spectrum extending below the lower frequency of Nyquist is called aliasing. The leftmost is the chromaticity confusion caused by the pixel sampling rate 38 'and the confusion 40 and the higher subpixel sampling rate Relevant, so will occur at higher frequencies. In Figure 6 A, the source spectrum has not been pre-filtered. Therefore, the aliasing caused by pixel sampling (ie, chromaticity aliasing) extends to a very low frequency 35. Therefore, Even if the chromaticity CSF has the bandwidth of the low-luminance CSF, the color epigenesis is still visible (depending on the noise and contrast of the display). In Figure 6B, the source power spectrum has been pre-filtered (equal to Source image pixel rect function), as shown by the dotted line 22 in Figure 4, and it can be found that it will affect the base-band spectrum 42 through 0_5 cycles / pixel (cy / pixei), resulting in it has a steeper than -1 The slope of is as indicated by 44. Repeating also shows the effect of this pre-filtering. Even using this filtering, we can find that some kind of chromaticity confusion occurs at the frequency 46 below the cut-off frequency of chromaticity CSF 32a and 34a (located in the more Low-frequency repetitive spectrum) ^ Therefore, it can be found that the simple type of luminance pre-filtering has a difficult time that is difficult to remove chrominance confusion 'and cannot be removed by 0 · 5 cycles / pixel (cy / pixel) (that is, the "advantage" area Block) of all brightness frequencies. Since we rely on the visual system bandwidth difference as a function of brightness or chrominance to provide brightness bandwidth improvement in the "Benefit Block" 20, one possibility is to pre-filter based on the visual system model design Please refer to c -10- for relevant instructions. This paper size applies Chinese National Standard (CNS) A4 specifications (210 X 297 mm) 558899 A7 B7 V. Description of invention (7)

Betrisey等人著作（2000)「Displaced filtering for patterned displays」SID Symposium digest 296-299，該文獻以提及方式併入本文中，如圖7所示。這項技術觀念上依據哪一層色彩層，以及依據要取樣影像的哪一個色彩次像素，以使用不同的預先濾波器。因此，有9個濾波器。他們已使用人類視差模型設計，相關說明請參考 X· Zhang 和 B· Wandell(1996)著作「A spatial extension of CIELab for digital color image reproduction」 SID Symp. Digest 73 1-734，該文獻以提及方式併入本文中，如圖7所示。這是以離線方式完成，假設影像一定是黑&白。在最後實施中，會使用rect函數儲存計算結果，而不是使用產生的濾波器。此外，仍然會發生某些殘留的色度錯誤，這是因為色度混淆延伸至低於色度CSF截止頻率以下的頻率（如圖6B所示）。但是，使用的視覺模型不考慮視覺系統的遮蓋特性，這會導致當亮度在中或高對比度等級時，色度被亮度遮蓋。所以，在較大的字形中，字形邊緣的色度后生現象會被字形的亮度對比度遮蓋。但是，隨著縮小字形大小，字形亮度會隨之縮小，然後同一色度后生現象會變得非常明顯（例如，在非常小的字形，字形的黑/白部份消失，只留下局部的色點（color speckle))。發明概要Betrisey et al. (2000) "Displaced filtering for patterned displays" SID Symposium digest 296-299, which is incorporated herein by reference, as shown in Figure 7. This technique conceptually depends on which color layer and which color sub-pixel of the image to sample to use different pre-filters. Therefore, there are 9 filters. They have been designed using a human parallax model. For a description, please refer to the work by X · Zhang and B · Wandell (1996) "A spatial extension of CIELab for digital color image reproduction" SID Symp. Digest 73 1-734, which is mentioned by reference Incorporated herein, as shown in Figure 7. This is done offline, assuming the image must be black & white. In the final implementation, the rect function is used to store the calculation results instead of using the resulting filter. In addition, some residual chrominance errors still occur because chrominance aliasing extends to frequencies below the chrominance CSF cutoff frequency (as shown in Figure 6B). However, the visual model used does not take into account the occlusion characteristics of the visual system, which can cause chromaticity to be obscured by luminance when the luminance is at a medium or high contrast level. Therefore, in larger glyphs, the chroma epigenesis at the edges of the glyphs is obscured by the brightness contrast of the glyphs. However, as the size of the glyph is reduced, the brightness of the glyph decreases, and then the epigenetic phenomenon of the same chromaticity becomes very obvious (for example, in very small glyphs, the black / white part of the glyph disappears, leaving only partial color Point (color speckle)). Summary of invention

本發明的設計係以前面提及的人類視覺系統空間頻率響應的特定為基礎，換言之，係以亮度CSF具有高於色度CSF -11 - 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A7The design of the present invention is based on the aforementioned specificity of the spatial frequency response of the human visual system, in other words, the brightness CSF is higher than the chromaticity CSF -11-This paper standard is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 558899 A7

=止頻率士基礎。運用本發明’低解析度影像的形成方式為，將-高解析度影像分割成_亮度資料與一色度資料抽以便執行適合該亮度資料與該色度資料的取樣及滤波， …、後於取樣足後梳刷（combing)該亮度資料與該色度資料 °就該色度資料而言’會執行傳統次取樣㈣免色度混清 (chromatic auasing) ’同時針對該亮度資料執行次像素取樣’以改良亮度分量解析度。另夕卜，會針對經過次像素取樣的亮度資料執行高通濾波，以去除於次像素取樣亮度資料期間發生的低頻后生現象。下文中將說明本發明的觀念。在圖丨和2中，藉由圖1所不（次取樣，顯示像素16中之R' G*B次像素1〇、12和14 各自的R、G和B值反映高解析度影像4之色彩像素8(即，u) 各自的R、G和B值《但是，次像素1〇、12和14各自的R、 G和B值不是完全相同於色彩像素8(11)各自的R、6和6值。因此，就亮度分量而言，會執行圖2所示的次像素取樣，使次像素10、12和14各自的r、g和B值反映色彩像素11 、13和15的亮度分量。本發明具體實施例包括較不依賴濾波的方法及系統，並且假設線性以及能夠處理輸入彩色影像。這些具體實施例均能夠直接去除次像素取樣所造成的低頻色度后生現象。這些藉由產生影像色度内容的LPF版本以加入至亮度及色度混淆版本的方式完成。這是藉由利用除了加色法原色域 (即，RGB)以外的色域以去除次像素取樣所造成之色彩后生現象的方式完成。實際上，只需要消除較低頻率色度后 -12- 本紙張尺度適用中國國家標準(CNS) A4規格(210X 297公袭：）= Stop Frequency Basis. The method of forming the low-resolution image of the present invention is to divide the high-resolution image into _ luminance data and a chroma data to extract and perform sampling and filtering suitable for the luminance data and the chroma data, ... Combing the luma data and the chroma data after the foot ° As far as the chroma data is concerned, 'the traditional subsampling will be performed chromatic chromatic auasing' and the subpixel sampling will be performed on the luma data at the same time ' To improve the brightness component resolution. In addition, high-pass filtering is performed on the luminance data sampled by the sub-pixel to remove the low-frequency epigenetic phenomenon that occurs during the luminance data sampled by the sub-pixel. Hereinafter, the concept of the present invention will be explained. In Figures 丨 and 2, the R, G, and B values of the subpixels 10, 12, and 14 of the R'G * B subpixels 10, 12, and 14 shown in Fig. 1 (subsampling) reflect the high resolution image 4 The respective R, G, and B values of color pixel 8 (ie, u) "However, the respective R, G, and B values of sub-pixels 10, 12, and 14 are not exactly the same as the respective R, 6 of color pixel 8 (11) And 6. For the luminance component, the sub-pixel sampling shown in FIG. 2 is performed so that the r, g, and B values of the sub-pixels 10, 12, and 14 reflect the luminance components of the color pixels 11, 13, and 15, respectively. The specific embodiments of the present invention include methods and systems that are less dependent on filtering, and are assumed to be linear and capable of processing input color images. These specific embodiments can directly remove low-frequency chroma epigenetics caused by sub-pixel sampling. These are generated by The LPF version of the image chroma content is completed by adding to the luma and chroma obfuscation version. This is to remove the color epigenesis caused by sub-pixel sampling by using a color gamut other than the additive color gamut (ie, RGB). Phenomenal way is done. In fact, only lower frequency colors need to be eliminated -12- This paper applies the scale of Chinese National Standard (CNS) A4 size (210X 297 public attack :)

裝訂Binding

558899 A7 B7 五、發明説明（9 ) 生現象，這是因為由於色度CSF的較低頻寬，所以看不到高頻色度后生現象，如圖6A所示。本發明的方法及系統可運用在獲取較高解析度亮度信號，而沒有明顯的色度混淆，這適合以遠於設計規格的距離觀看顯示器的情況。這些技術不需要假設來源影像是文字或假設影像是消色差。本發明具體實施例將較高解析度影像轉換成較低解析度影像，並且減少次取樣處理程序造成的錯誤。當較高解析度彩色影像不是允許分隔亮度與色度資料的格式時，則會將影像轉換成此類格式。許多對比色域（opponent color domain)均可接受β對比色域（opponent color domain)被分割，藉此分隔亮度通道與色度通道，以允許分開處理。然後，將亮度通道轉換成加色域（additive color domain ;ACD)，如RGB，並且ACD亮度影像被次像素取樣，以在降低解析度時保存亮度資料。在次像素取樣之後，經過次像素取樣（SPS)的影像被轉換回對比色域（opponent color domain ; OCD)，並且再次分割成分開的亮度和色度通道。然後，這個分割處理所產生的SPS色度通道經過高通濾波，以去除於次像素取樣期間產生的低頻色度后生現象。通常不會修改SPS亮度通道以保存原始亮度資料。然後，將來自於原始影像的色度通道經過低通濾波，接著經過次取樣以提供較低解析度影像的色度資料。然後，將經過低通濾波的色度通道組合從原始亮度通道建立之經過高通濾波、次像素取樣的色度通道。還會將這些組合的 -13- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A7558899 A7 B7 V. Description of the invention (9) This phenomenon is due to the low bandwidth of the chromaticity CSF, so no high frequency chromaticity epigenesis can be seen, as shown in Figure 6A. The method and system of the present invention can be used to obtain a higher-resolution luminance signal without significant chromaticity confusion, which is suitable for viewing the display at a distance farther than the design specification. These techniques do not require the source image to be text or the image to be achromatic. A specific embodiment of the present invention converts a higher-resolution image into a lower-resolution image, and reduces errors caused by the sub-sampling processing program. When higher resolution color images are not in a format that allows separation of luma and chroma data, the image is converted to such a format. Many contrast color domains can be divided into beta contrast color domains, thereby separating the luminance channel from the chrominance channel to allow separate processing. Then, the brightness channel is converted into an additive color domain (ACD), such as RGB, and the ACD brightness image is sampled by sub-pixels to save the brightness data when the resolution is reduced. After sub-pixel sampling, the image after sub-pixel sampling (SPS) is converted back to the contrast color domain (OCD), and the separated luminance and chrominance channels are again segmented. Then, the SPS chrominance channel generated by this segmentation process is subjected to high-pass filtering to remove the low-frequency chrominance epigenesis generated during the sub-pixel sampling period. The SPS brightness channel is usually not modified to save the original brightness data. Then, the chroma channel from the original image is low-pass filtered, and then sub-sampled to provide chroma data for the lower resolution image. Then, the low-pass filtered chroma channels are combined with the high-pass filtered, sub-pixel sampled chroma channels established from the original luminance channel. -13- These paper sizes are also applicable to China National Standard (CNS) A4 (210 X 297 mm) 558899 A7

色度通遒組合SpS亮度通道，以形成減少錯誤、較低解析度影像，通常是對比色域。然後，可將減少錯誤、較低解析度衫像轉換將加色域或相容於所期望之應用的其他色域。圖式簡單說明Chroma is usually combined with the SpS luminance channel to form a reduced-error, lower-resolution image, usually a contrasting color gamut. The reduced error, lower resolution shirt image can then be converted to add color gamut or other color gamut compatible with the desired application. Schematic illustration

為了獲得本發明之前面列舉及其他優點和目的的方法，將參考如附圖所示之本發明特定具體實施例來呈現前面簡短說明之本發明的更具體說明。應明白，這些圖式僅描繪本發明典型的具體實施例，因此，不應視為限制本發明的範蜂，將利用附圖說明及解說本發明的額外具體性及細節，其中：裝圖1顯示適用於三基色像素組態之顯示器的傳統影像取樣，訂In order to obtain the methods listed above and other advantages and objectives of the present invention, a more detailed description of the present invention briefly described above will be presented with reference to specific embodiments of the present invention as shown in the accompanying drawings. It should be understood that these drawings depict only typical specific embodiments of the present invention, and therefore should not be considered as limiting the present invention. Additional details and details of the present invention will be described and illustrated with the accompanying drawings, in which: Figure 1 Display traditional image sampling for display with three primary color pixel configurations, order

圖2顯示適用於三基色像素組態之顯示器的次像素影像取樣；圖3顯示映射至數位頻率標繪圖之理想化cSi^々圖式；圖4顯示像素Nyquist分析以及標示優點區塊的次像素 Nyquist區塊；圖5顯示典型的預先處理技術；圖6 A顯示使用以像素取樣及次像素取樣頻率重複之1 /f 功率譜之分析的圖式；圖6B顯示使用以因預先處理而改良之像素取樣及次像素取樣頻率重複之1 /f功率譜之分析的圖式；圖7顯示視覺模型已知用途的方塊圖；圖8顯示本發明具體實施例的流程圖； -14- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899Figure 2 shows sub-pixel image sampling suitable for a display with three primary color pixel configurations; Figure 3 shows the idealized cSi ^ 々 pattern mapped to a digital frequency plot; Figure 4 shows the Nyquist analysis of pixels and the sub-pixels that mark the merits Nyquist block; Figure 5 shows a typical pre-processing technique; Figure 6 A shows a diagram using analysis of a 1 / f power spectrum repeated at pixel sampling and sub-pixel sampling frequency; Figure 6B shows a modification using pre-processing Schematic diagram of 1 / f power spectrum analysis of pixel sampling and sub-pixel sampling frequency repetition; Figure 7 shows a block diagram of known uses of visual models; Figure 8 shows a flowchart of a specific embodiment of the present invention; -14- this paper scale Applicable to China National Standard (CNS) A4 (210 X 297 mm) 558899

圖9顯示本發明特定具體實施例的流程圖；以及圖10顯示本發明具體實施例所保留之信號的圖式。實施本發明的模式藉由參考圖式即可更加瞭解本發明目前的較佳具體實施例’其中整份圖式中相似的部件係以相似的數字標示。前面列出的圖式明確併入本詳細說明的一部份。如本文中的廣泛說明及圖式中的圖解，很容易明白可用各種不同的組態來排列及設計本發明的組件。因此，下文中本發明方法及系統之具體實施例的更詳細說明不是用來限制本發明的範疇，而僅僅是代表本發明目前的較佳具體實施例。可用硬體、韌體或軟體來具體化本發明具體實施例的元件。另外，可在電腦可讀取媒體中儲存軟體，以此方式提供具體化本發明具體實施例功能的軟體（程式）。除了如資訊儲存裝置（半導體記憶體、軟碟片、硬碟機等等）和光學儲存裝置（CD-ROM、DVD等等）之類的記錄媒體以外，此類媒體的實例這包括電腦網路（區塊網路（Lan)、網際網路等之類的廣域網路（WAN)及無線通信網路）系統中使用的通信媒體（光纖、無線通信線路等等）❶另外，還可將本發明具體實施例功能實現成為於電子傳輸中具體化的電腦信號。雖然本文中揭示的示範性具體實施例只說明這些形式的一種形式’但是熟知技藝人士應知道，能夠用這些形式的任一種形式來實行這些元件，而均屬本發明的範蜂。 -15-本紙張尺度適用中國國家標準(CNS) A4規格(210X 297公釐) 558899 A7 B7 五、發明説明（12 ) 將參考術語「消色差」來說明及提出本發明的具體實施例。當與本說明書及附圖中的影像一起使用時，術語「消色差」表示沒有可見色彩變化的影像。消色差影像是一種只包括一層或色彩通道的影像，或是一種像具有多層或色彩通道’但是每層色彩層完全一樣藉此產生單一色彩影像的影像。將參考術㊂吾「RGB」影像或色域、或「加色域」（additive color domain)或「加色影像」（additive color image)來說明及提出本發明的具體實施例。在本說明書及相關申請專利範圍中，這些術語可代表任何形式的多重分量影像域，其具有包括但不限於各種RGB色域及CMYK色域的亮度資訊及色度資訊。還會參考「YCrCb」影像或色域、「對比色」(〇pp0nent color) 色域、影像或通道，或「色差」（color difference)色域、影像或通道來說明及提出本發明的具體實施例。在本說明書及相關申請專利範圍中，這些術語可代表任何形式的多重分量影像域，其具有包括但不限於YCrCb、LAB、YUV 及YIQ色域的不同亮度通道及色度通道。本發明具體實施例可用來將較高解析度影像轉換成較低解析度影像，並且轉換的介面中具有較少的可視錯誤。雖然這些具體實施例通常是與顯示裝置一起使用，用以將解析度高於顯示器解析度的影像向下轉換成顯示器可用的解析度，但是也適用於其他應用。經過本發明具體實施例轉換的影像可以各種格式存在。 -16- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 裝訂Fig. 9 shows a flowchart of a specific embodiment of the invention; and Fig. 10 shows a diagram of signals retained by a specific embodiment of the invention. Modes for Carrying Out the Invention By referring to the drawings, one can better understand the presently preferred embodiments of the present invention, wherein similar parts throughout the drawings are indicated by similar numbers. The illustrations listed earlier are explicitly incorporated into this detailed description. As broadly described herein and illustrated in the drawings, it will be readily apparent that the components of the present invention can be arranged and designed in a variety of different configurations. Therefore, the following more detailed description of the specific embodiments of the method and system of the present invention is not intended to limit the scope of the present invention, but merely represents the presently preferred specific embodiments of the present invention. Hardware, firmware, or software may be used to embody the elements of a particular embodiment of the invention. In addition, software can be stored in a computer-readable medium, in this way, software (program) embodying functions of specific embodiments of the present invention is provided. In addition to recording media such as information storage devices (semiconductor memory, floppy disks, hard drives, etc.) and optical storage devices (CD-ROM, DVD, etc.), examples of such media include computer networks (Broadband network (Lan), Internet, and other wide area network (WAN) and wireless communication networks) Communication media (optical fiber, wireless communication lines, etc.) used in the system The function of the specific embodiment is realized as a computer signal embodied in electronic transmission. Although the exemplary embodiments disclosed herein only illustrate one form of these forms', those skilled in the art should know that it is possible to implement these elements in any of these forms, which are all examples of the present invention. -15- This paper size applies Chinese National Standard (CNS) A4 specification (210X 297 mm) 558899 A7 B7 V. Description of the invention (12) The term "achromatic" will be used to explain and propose specific embodiments of the present invention. When used with the images in this specification and the drawings, the term "achromatic" means an image that has no visible color change. An achromatic image is an image that includes only one layer or color channel, or an image that has multiple layers or color channels, but each color layer is exactly the same to produce a single color image. Specific embodiments of the present invention will be explained and proposed with reference to the "RGB" image or color gamut, or "additive color domain" or "additive color image" of the art. In the scope of this specification and the patents of related applications, these terms may represent any form of multi-component image domain, which includes, but is not limited to, various RGB color gamuts and CMYK color gamuts. Reference will also be made to the "YCrCb" image or color gamut, "opp0nent color" color gamut, image, or channel, or "color difference" color gamut, image, or channel to explain and propose specific embodiments of the present invention . In the scope of this specification and related patent applications, these terms can represent any form of multi-component image domains with different luminance channels and chrominance channels including, but not limited to, YCrCb, LAB, YUV, and YIQ color gamuts. The specific embodiment of the present invention can be used to convert a higher-resolution image into a lower-resolution image, and there are fewer visible errors in the converted interface. Although these specific embodiments are often used with display devices to down-convert an image with a resolution higher than that of the display to a resolution available to the display, it is also applicable to other applications. The images converted by the specific embodiments of the present invention may exist in various formats. -16- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) binding

線 558899 A7 B7 五、發明説明（13 ) 當這些格式不相容於本發明具體實施例的處理程序時，則在處理之前先將影像轉換成可相容的格式，並且在處理後，視需要將影像轉換回原格式。可參考圖8來解說本發明具體實施例，圖中顯示概述具體實施例的圖式。這個處理程序70以存在於對比色域 (opponent color domain ; OCD)中的影像開始，如 YCrCb、 LAB、YUV、YIQ或類似的色域。當影像係存在於如RGB 或CMYK色域或某種其他色彩空間之類的「加色域」 (additive color domain ; ACD)中時，可先將影像轉換成對比色域，之後才使用本發明具體實施例處理轉換後的影像。某些具體實施例包括用以在處理之前先將影像轉換成可相容格式的步驟。一旦影像屬於對比色域72，並且具有分開的亮度通道及色度通道，則會將影像「分割」（步驟74)以分開處理亮度通道及色度通道。「分割」（步驟74)可包括取樣或濾波原始OCD影像72，或從原始影像72離析亮度資料或色度資料的方法。分割還可包括影像轉換。分割之後，將起始亮度通道76轉換（步驟78)成ACD亮度影像，如RGB影像。這是為了能夠以最終顯示亮度影像的格式或色域來取樣亮度影像。一旦亮度影像已經過轉換（步驟78)，隨即對影像執行次像素取樣（步驟80)，以改良產生之較低解析度影像的解析度。在此方法中，來自於原始較高解析度影像中每個連續像素的亮度資料被指派給較低解析度影像中對應的每個次像素。 -17- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A7 B7 五、發明説明（14 ) 當完成次像素取樣（步驟80)時，會產生次像素取樣（SPS) 亮度影像，這個SPS亮度影像被轉換（步驟82)成OCD影像，可稱為SPS-OCD亮度影像。執行這個轉換是為了允許將 SPS亮度影像進一步分割（步驟84)成分開的亮度通道及色度通道。SPS亮度通道86通常維持原狀，直接後續組合（步驟88)其他通道。然而，會先濾波SPS色度通道90&92，之後才會進一步組合。可將這些SPS色度通道90&92分割成紅色轉綠色（Red-to-Green)通道90及藍色轉黃色（Blue-to-Yellow)通道92。這些通道通常包括YCrCb影像的Cr和Cb通道、LAB影像的「a」和「b」通道、YUV影像的U和V通道、YIQ影像的I和Q通道或其他色彩空間的色域的類似通道。然後，色度通道 90&92經過高通濾波（步驟94&96)，以去除於次像素取樣期間發生的低頻后生現象。在本發明的某些具體實施例中，暈光蒙片法（unsharp mask method)來執行高通濾波（步驟94 &96)。暈光蒙片可使用低通核心。通常會使用產生影像低通版本的低通核心來處理原始影像。接著，原始未濾波影像減去這個低通版本，同時保存影像的平均值。成功的具體實施例已使用高斯（Gaussian)低通核心，其中sigma約0.3像素至0.8像素。0.6 像素的sigma值被認為特別成功，並且產生約0.168循環/像素（cycle/pixel)頻率領域的截止頻率。這提供非常理想的暈光蒙片濾波器。下文提供導出高斯（Gaussian)核心的說明。 -18- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 裝訂Line 558899 A7 B7 V. Description of the invention (13) When these formats are not compatible with the processing procedure of the specific embodiment of the present invention, the image is converted into a compatible format before processing, and after processing, as needed Convert the image back to the original format. A specific embodiment of the present invention can be explained with reference to FIG. 8, which shows a diagram outlining a specific embodiment. This processing program 70 starts with an image existing in an contrast color gamut (OCD), such as YCrCb, LAB, YUV, YIQ, or a similar color gamut. When an image exists in an "additive color domain" (ACD) such as the RGB or CMYK color gamut or some other color space, the image can be converted into a contrast color gamut before using the invention. The embodiment processes the converted image. Some embodiments include steps to convert the image to a compatible format before processing. Once the image belongs to the contrast color gamut 72 and has separate luminance and chrominance channels, the image will be "segmented" (step 74) to separately process the luminance and chrominance channels. "Segmentation" (step 74) may include a method of sampling or filtering the original OCD image 72, or isolating the luminance data or chrominance data from the original image 72. Segmentation can also include image conversion. After segmentation, the initial luminance channel 76 is converted (step 78) into an ACD luminance image, such as an RGB image. This is to enable the luminance image to be sampled in the format or color gamut where the luminance image is ultimately displayed. Once the luminance image has been converted (step 78), sub-pixel sampling is performed on the image (step 80) to improve the resolution of the lower-resolution image produced. In this method, luminance data from each successive pixel in the original higher-resolution image is assigned to each corresponding sub-pixel in the lower-resolution image. -17- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 558899 A7 B7 V. Description of the invention (14) When sub-pixel sampling (step 80) is completed, sub-pixel sampling (SPS) ) Brightness image. This SPS brightness image is converted (step 82) into an OCD image, which can be referred to as an SPS-OCD brightness image. This conversion is performed to allow further segmentation (step 84) of the SPS luminance image into separate luminance and chrominance channels. The SPS brightness channel 86 is usually maintained as it is, and the other channels are directly combined (step 88). However, the SPS chrominance channels 90 & 92 are filtered before being further combined. These SPS chroma channels 90 & 92 can be divided into a red-to-green channel 90 and a blue-to-yellow channel 92. These channels usually include the Cr and Cb channels of the YCrCb image, the "a" and "b" channels of the LAB image, the U and V channels of the YUV image, the I and Q channels of the YIQ image, or similar channels in the color gamut of other color spaces. Then, the chroma channel 90 & 92 is high-pass filtered (step 94 & 96) to remove the low-frequency epigenetic phenomenon occurring during the sub-pixel sampling. In some embodiments of the present invention, an unsharp mask method is used to perform high-pass filtering (steps 94 & 96). The halo mask can use a low-pass core. The low-pass core that produces the low-pass version of the image is usually used to process the original image. The original unfiltered image is then subtracted from this low-pass version while the average value of the image is saved. Successful embodiments have used Gaussian low-pass cores, where the sigma is about 0.3 pixels to 0.8 pixels. A sigma value of 0.6 pixels is considered particularly successful and produces a cut-off frequency in the frequency domain of about 0.168 cycles / pixel. This provides a very ideal halo mask filter. Instructions for deriving the Gaussian core are provided below. -18- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) binding

558899 A7 B7 五、發明説明（15 在某些具體實施例中，使用如下所示的一維高斯 (Gaussian)函數·· = —4-^2/2σ2 μ=0 (1) 這個函數的傅立葉轉換如下所示： = (2) 此處可發現到’空間領域中的σ(像素單元）相當於頻率領域中的1/π2σ(猶環/像素單位）。這項關係有助於在已知〇的情況下決定濾波器的截止頻率，反之，在已知頻率的情況下決定暈光蒙片的空間σ，這可藉由CSF模型引導。在某些具體實施例中，使用如下所示的二維高斯 (Gaussian)函數: 裝尸(X，少）= —1 c 12σχ ΐσΐ) 2πσ,σ少558899 A7 B7 V. Description of the invention (15 In some specific embodiments, the one-dimensional Gaussian function shown below is used .... = -4- ^ 2 / 2σ2 μ = 0 (1) Fourier transform of this function It is shown as follows: = (2) It can be found here that σ (pixel unit) in the spatial domain is equivalent to 1 / π2σ (Jewel / pixel unit) in the frequency domain. This relationship helps to know The cutoff frequency of the filter is determined in the case of ， and conversely, the space σ of the halo mask is determined under the known frequency, which can be guided by the CSF model. In some specific embodiments, the following two are used Gaussian function: Body loading (X, less) = —1 c 12σχ ΐσΐ) 2πσ, less σ

(3) 由於高斯（Gaussian)函數是可分割的笛卡兒（Cartesian), 所以當考慮到σ的重要性時，二維高斯（Gaussian)函數的頻率響應類似於方程式（2)。也就是說，時間領域中的〜是頻率領域中的1/π2σχ，而時間領域中的^是頻率領域中的 1/π2σγ 〇本發明的一項成功具體實施例已採用以3χ3核心大小實施的高斯（Gaussian)暈光蒙片濾波器，其中選用的值為0 · 6 ’而導致低通/慮波器的截止頻率約為〇 · 2循環/像素。訂(3) Since the Gaussian function is a separable Cartesian, when considering the importance of σ, the frequency response of the two-dimensional Gaussian function is similar to equation (2). That is, ~ in the time domain is 1 / π2σχ in the frequency domain, and ^ in the time domain is 1 / π2σγ in the frequency domain. A successful embodiment of the present invention has been implemented using a 3 × 3 core size. Gaussian halo mask filter. The selected value is 0 · 6 ', which causes the cut-off frequency of the low-pass / filter to be about 0.2 cycles / pixel. Order

k -19- 本紙張尺度適用中國國家標準(CMS) A4规格(210X 297公袭:) 558899k -19- This paper size applies the Chinese National Standard (CMS) A4 specification (210X 297 public attack :) 558899

本發明的其他具體實施例可使用高通濾波器，其同等於各自對比色彩通道的反向CSF。這些CSF可從cy/deg領域（已模型化）映射至循環/像素（0^/]?匕)數位領域。實際的映射處理程序考慮到觀看距離，並且允許針對不同的應用自訂化’使用以像素/毫米（pixel/mm)為單位的特殊顯示解析度 ’以及不同的預期或預計觀看距離。由於本發明的方法，所以當以遠於設計觀看距離的距離觀看顯示器，不會看到色度后生現象《但是，可改良亮度解析度。可依據特定取樣處理程序引起的后生現象總量或強度，或依據某些其他準則，針對所有的色度通道9〇&92或所選通道來執行濾波（步驟94&96)。原始OCD色度通道98&100的低通濾波（步驟1〇2&1〇4)可與亮度途徑105的處理過程同時發生，或於其他時間發生。執行OCD色度通道98&100的低通濾波（步驟i〇2&1〇4)，以去除顯示像素Nyquist頻率以上的實質色度頻率。因此 ’可用傳統方式以1 : 3因數來次取樣（步驟i〇i&i〇3)這些通道’而不會在色度途徑11〇中產生色度混淆。一旦完成濾波作業，就可組合被隔離的通道。色度通道組合會因用的色域而異。在這個示範性具體實施例中，會將高通濾波、次像素取樣的藍色轉黃色（HPFSPS-B/Y)色度通道97組合（步驟1〇6)低通濾波、傳統素取樣的藍色轉黃色（LPFSS-B/Y)色度通道1〇9，以構成單一高低滤波器 (HLF)B/Y色度通道111。還會將高通濾波、次像素取樣的紅色轉綠色（HPFSPS-R/G)通道95組合（步驟108)低通濾波 -20-本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A7 B7 五、發明説明（17 ) 、傳統素取樣的紅色轉綠色LPFSS-R/G)通道107，以構成單一高低濾波器（HLF)R/G通道114。請注意，本發明具體實施例的方法適用於其他色彩空間及色域，其可包括其他色彩通道和其他色彩通道量，以及亮度或明亮度通道的其他變化。可將組合的111^色度通道111&114進一步組合（步驟8 8) SPS亮度通道86，以構成較低解析度OCD影像116。然後，可按各種用途的需求，將較低解析度OCD影像116轉換成其他影像格式或領域。這些具體實施例的方法及系統提供具有較少可見色度后生現象的較低解析度影像。此外，可用各種方法修改前面的具體實施例。例如，在某些情況下，可忽略色度通道98& 100的低通濾波（步驟 102&104)。另外，可單獨使用已分割（步驟74)的亮度通道 76來構成較低解析度影像116。換言之，可執行與亮度通道76相關之亮度途徑105的每個步驟，同時忽略與色度通道98& 100相關之色度途徑110的每個步驟及步驟106和108 ，以便組合SPS亮度通道86與HPFSPS-R/G通道95和 HPFSPS-B/Y通道97。在此方法中，能夠構成較低解析度影像116。Other embodiments of the present invention may use a high-pass filter, which is equivalent to the inverse CSF of the respective contrast color channel. These CSFs can be mapped from the cy / deg domain (modeled) to the loop / pixel (0 ^ /]? D) digital domain. The actual mapping handler takes into account the viewing distance and allows customization of 'the use of special display resolutions in pixels / mm (pixel / mm)' for different applications and different expected or projected viewing distances. Due to the method of the present invention, when the display is viewed at a distance farther than the designed viewing distance, the chroma epigenesis phenomenon will not be seen. However, the brightness resolution can be improved. Filtering can be performed on all chrominance channels 90 & 92 or selected channels based on the total amount or intensity of epigenetic phenomena caused by a particular sampling process (steps 94 & 96). The low-pass filtering of the original OCD chrominance channel 98 & 100 (step 102 & 104) can occur simultaneously with the processing of the luminance channel 105, or at other times. A low-pass filtering of the OCD chrominance channel 98 & 100 is performed (step 102 and 104) to remove the substantial chrominance frequency above the Nyquist frequency of the display pixel. So 'the channels can be sampled (steps ioi & i03) in a conventional manner with a factor of 1: 3' without generating chromaticity confusion in the chrominance pathway 11o. Once the filtering operation is completed, the isolated channels can be combined. The chrominance channel combination will vary depending on the color gamut used. In this exemplary embodiment, the high-pass filtering, sub-pixel sampling blue to yellow (HPFSPS-B / Y) chroma channel 97 is combined (step 106), and the low-pass filtering, traditional prime sampling blue Turn the yellow (LPFSS-B / Y) chrominance channel 10 to form a single high-low filter (HLF) B / Y chrominance channel 111. It will also combine high-pass filtering and sub-pixel sampling red-to-green (HPFSPS-R / G) channel 95 combination (step 108) low-pass filtering -20- This paper size applies to China National Standard (CNS) A4 specifications (210 X 297 male (Centi) 558899 A7 B7 5. Description of the invention (17), the traditional prime sampling red to green LPFSS-R / G) channel 107, to form a single high-low filter (HLF) R / G channel 114. Please note that the method of the specific embodiment of the present invention is applicable to other color spaces and color gamuts, which may include other color channels and other color channel quantities, and other changes in the brightness or brightness channels. The combined 111 ^ chroma channels 111 & 114 can be further combined (step 88) SPS luminance channel 86 to form a lower resolution OCD image 116. Then, the lower resolution OCD image 116 can be converted into other image formats or fields according to the needs of various applications. The methods and systems of these embodiments provide lower resolution images with less visible chrominance. In addition, the foregoing specific embodiments may be modified in various ways. For example, in some cases, the low-pass filtering of the chroma channel 98 & 100 may be ignored (step 102 & 104). Alternatively, the segmented (step 74) luminance channel 76 may be used alone to construct the lower resolution image 116. In other words, each step of the luminance path 105 related to the luminance channel 76 can be performed, while each step of the chrominance path 110 and steps 106 and 108 related to the chrominance channel 98 & 100 are ignored, in order to combine the SPS luminance channel 86 and HPFSPS-R / G channel 95 and HPFSPS-B / Y channel 97. In this method, a lower-resolution image 116 can be constructed.

現在參考圖9來解說本發明的特定示範性具體實施例。這個特定具體實施例可用來處理較高解析度RGB影像，用以在較低解析度顯示裝置上顯示影像。可依據使用者或應用的特定需求，視需要預先處理（步驟122)較高解析度RGB -21 - 本紙張尺度適用中國國家標準(CNS) A4規格(210X297公釐) 裝訂Referring now to FIG. 9, a specific exemplary embodiment of the present invention is explained. This particular embodiment can be used to process higher-resolution RGB images for displaying images on lower-resolution display devices. Can be pre-processed (step 122) according to the specific needs of the user or application (step 122) Higher resolution RGB -21-This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) Binding

558899 A7 B7 五、發明説明（18 ) 影像120。預先處理（步驟122)可包括微量壓縮（hinting)，低通濾波或其他處理技術類型。預先處理（步驟122)也可完全略過。預先處理（步驟122)之後，可將RGB轉換（步驟124)成對比色域（opponent color domain)，如 LAB、YCrCb、YIQ、 YUV或其他影像色域。在此實例中，使用LAB影像色域。一旦轉換成這個色域，就可將影像分割（步驟126)成分開的L、a和b色域通道，以分開處理通道。在此方法中，可分開處理色度通道和亮度通道。然後，將「L」通道127轉換（步驟128)回RGB色域，以致能夠以最終顯示格式來進行取樣。這個轉換可包括將L 層或通道直接複製到三個完全一樣的R、G和B層。但是，也可使用單層，實際的轉換方法視所選用的色彩轉換而定。然後對RGB亮度影像執行次像素取樣（步驟130)，以保存原始RGB影像120的水平亮度解析度。次像素取樣之後，再次將經過取樣的影像轉換（步驟132)成對比色域 (opponent color domain ; OCD)，如 LAB。這個經過取樣的LAB影像被分割（步驟134)，以隔離亮度通道及色度通道，以進一步處理色度通道。此處，通常不會處理SPS亮度通道以保存原始亮度資料。但是，經過次像素取樣的色度通道150&152及分割影像均經過高通濾波（步驟146&148) ，以去除於次像素取樣期間發生的低頻后生現象混淆。如同前面解說的具體實施例，可使用運用高斯（Gaussian) 低通核心的暈光蒙片濾波器來執行高通濾波。在使用這種 -22- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐）裝訂558899 A7 B7 V. Description of the invention (18) Image 120. The pre-processing (step 122) may include hinting, low-pass filtering, or other types of processing techniques. The pre-processing (step 122) can also be completely skipped. After pre-processing (step 122), the RGB conversion (step 124) can be performed into an opponent color domain, such as LAB, YCrCb, YIQ, YUV, or other image color gamuts. In this example, the LAB image color gamut is used. Once converted into this color gamut, the image can be segmented (step 126) into L, a, and b color gamut channels to separate the processing channels. In this method, the chrominance and luma channels can be processed separately. The "L" channel 127 is then converted (step 128) back to the RGB color gamut so that it can be sampled in the final display format. This transformation can include copying the L layer or channel directly to three identical R, G, and B layers. However, a single layer can also be used, and the actual conversion method depends on the color conversion selected. Sub-pixel sampling is then performed on the RGB luminance image (step 130) to preserve the horizontal luminance resolution of the original RGB image 120. After the sub-pixel sampling, the sampled image is converted again (step 132) into an contrast color domain (OCD), such as LAB. The sampled LAB image is segmented (step 134) to isolate the luminance channel and chrominance channel for further processing of the chrominance channel. Here, the SPS brightness channel is usually not processed to save the original brightness data. However, the chroma channel 150 & 152 and the segmented image after sub-pixel sampling are all subjected to high-pass filtering (step 146 & 148) to remove the low-frequency epigenetic confusion that occurs during the sub-pixel sampling. As with the specific embodiment explained previously, a high-pass filtering may be performed using a halo mask filter using a Gaussian low-pass core. When using this -22- this paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) binding

558899 A7 B7 五、發明説明（19 ) 方法的具體實施例中，色度通道被濾波以產生低通濾波色度影像’這是從SPS-RGB色度影像減去的色度影像，以形成「高通」濾波（HPF)SPS色度影像或通道i47&149。通常會對「a」和「b」通道執行高通濾波（步驟i46&148),但是當條件許可時，也可只對其中一通道執行高通濾波。原始「a」和「b」色度通道154&156的低通濾波（步驟 138&140)可在處理「L」通道時同時發生，或於其他時間發生。執行「a」和「b」色度通道的低通濾波（步驟138&14〇) ，以去除顯示像素Nyquist頻率以上的實質色度頻率。低通濾波（步驟138& 140)之後，可用傳統方式以1 : 3因數來次取樣（步驟142& 144)這些通道，而不會產生色度混淆。當通道已經過濾波及取樣時，就會組合通道以構成具有較少錯誤的較低解析度影像。將經過高通濾波的「a」亮度通道147組合（步驟160)經過次取樣、低通濾波的「a」通道143，以構成經過處理的ra」通道164。將經過高通濾波的「b」亮度通道149組合（步驟158)經過次取樣、低通濾波的「b」通道145，以構成經過處理的「b」通道162 。然後’將色度通道162&164組合（步驟166)SPS亮度通道 136 ’以構成減少錯誤、較低解析度lab影像168。可將減少錯誤的影像轉換（步驟丨70)成RGB色域，以產生減少錯誤、較低解析度RGB影像172，這些影像可輸出至顯示器或其他裝置。現在參考圖10來解說本發明具體實施例處理程序的功能，圖中顯示與亮度CSF 180和色度CSF 182相關的保留信號 -23- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐)558899 A7 B7 V. Description of the Invention (19) In the specific embodiment of the method, the chroma channel is filtered to generate a low-pass filtered chroma image. This is a chroma image subtracted from the SPS-RGB chroma image to form " High-pass filtering (HPF) SPS chroma image or channel i47 & 149. High-pass filtering is usually performed on the “a” and “b” channels (step i46 & 148), but when conditions permit, high-pass filtering can be performed on only one of the channels. The low-pass filtering (steps 138 & 140) of the original "a" and "b" chrominance channels 154 & 156 can occur simultaneously while processing the "L" channel, or at other times. Low-pass filtering of the "a" and "b" chroma channels is performed (step 138 & 14) to remove the substantial chroma frequency above the Nyquist frequency of the display pixel. After low-pass filtering (steps 138 & 140), these channels can be sampled (step 142 & 144) in a conventional manner with a factor of 1: 3 without chrominance confusion. When the channels have been filtered and sampled, the channels are combined to form a lower resolution image with fewer errors. The high-pass filtered "a" luminance channel 147 is combined (step 160) through the sub-sampled and low-pass filtered "a" channel 143 to form a processed ra "channel 164. The high-pass filtered "b" luminance channel 149 is combined (step 158) and the sub-sampled and low-pass filtered "b" channel 145 is combined to form a processed "b" channel 162. Then, the chrominance channel 162 & 164 is combined (step 166), and the SPS luminance channel 136 'is used to form a lower-resolution, lower-resolution lab image 168. The error-reduced images can be converted (step 70) to RGB color gamut to produce error-reduced, lower-resolution RGB images 172, which can be output to a display or other device. The function of the processing procedure of the specific embodiment of the present invention will now be described with reference to FIG. 10, which shows the reserved signals related to the luminance CSF 180 and chrominance CSF 182. -23- This paper standard applies to China National Standard (CNS) A4 specification (210 X (297 mm)

Claims

A B c DA B c D

558899 第090130880號專利申請案中文申請專利範圍替換本(92年6月) 々、申請專利耗圍 1. 一種用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤的方法，該方法包括下列動作：將一較高解析度對比色域（opponent color domain ; 0CD)影像分割成分開的一起始亮度通道及一個或一個以上起始色度通道；對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive color domain ; ACD)亮度影像；將該ACD亮度影像轉換成一 0CD亮度影像；將該OCD亮度影像分割成分開的一次像素取樣（SPS) 亮度通道及一個或一個以上SPS色度通道；高通濾波該等一個或一個以上SPS色度通道；以及組合該等一個或一個以上已高通濾波SPS色度通道與該SPS亮度通道，以構成一減少錯誤之較低解析度影像。 2. —種用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤的裝置，該裝置包括：分割裝置，用以將一較高解析度對比色域（opponent color domain ; OCD)影像分割成分開的一起始亮度通道及一個或一個以上起始色度通道；次像素取樣裝置，用以對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive color domain ; ACD) 亮度影像；轉換裝置，用以將該ACD亮度影像轉換成一 OCD亮度影像；分割裝置，用以將該0CD亮度影像分割成分開的一次 O:\75\75526-920603 DOC\ 7 - 1 - 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899558899 Patent Application No. 090130880 Chinese Application for Patent Scope Replacement (June 1992) 々, Patent Application Consumption 1. A method for converting a higher resolution image into a lower resolution image and reducing visible errors The method includes the following actions: segmenting a higher resolution contrast color domain (OCD) image into an initial luminance channel and one or more initial chrominance channels; performing a second time on the initial luminance channel Pixel sampling, thereby creating an additive color domain (ACD) brightness image; converting the ACD brightness image into a 0CD brightness image; segmenting the OCD brightness image into one pixel sampling (SPS) brightness channel and one Or one or more SPS chrominance channels; high-pass filtering the one or more SPS chrominance channels; and combining the one or more high-pass filtered SPS chrominance channels with the SPS luminance channel to form a lower error reduction Resolution image. 2. A device for converting a higher resolution image into a lower resolution image and reducing visible errors, the device includes: a segmentation device for converting a higher resolution contrast color gamut (OCD) ) An initial luminance channel and one or more initial chrominance channels separated by image segmentation; a sub-pixel sampling device for performing sub-pixel sampling on the initial luminance channel, thereby establishing an additive color domain ACD) brightness image; a conversion device for converting the ACD brightness image into an OCD brightness image; a segmentation device for splitting the 0CD brightness image into one O: \ 75 \ 75526-920603 DOC \ 7-1 -This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 558899

A8 i 说· ΰ· B8 :!年 G C8 ] D8 L______, 申請專利範圍像素取樣（SPS)亮度通道及一個或一個以上SPS色度通道；高通濾波器，用以高通濾波該等一個或一個以上SPS 色度通道；以及組合裝置，用以組合該等一個或一個以上已高通濾波 SPS色度通道與該SPS亮度通道，以構成一減少錯誤之較低解析度影像。一種儲存用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤之方法的電腦可讀取媒體，該方法包括下列動作：將一較高解析度對比色域（opponent color domain ; OCD)影像分割成分開的一起始亮度通道及一個或一個以上起始色度通道；對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive colo rdomain ; ACD)亮度影像；將該ACD亮度影像轉換成一 OCD亮度影像；將該OCD亮度影像分割成分開的一次像素取樣（SPS) 亮度通道及一個或一個以上SPS色度通道；高通濾波該等一個或一個以上SPS色度通道；以及組合該等一個或一個以上已高通濾波SPS色度通道與該SPS亮度通道，以構成一減少錯誤之較低解析度影像。一種用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤的方法，該方法包括下列動作：將一較高解析度對比色域（opponent color domain ; OCD)影像分割成分開的一起始亮度通道及數個起始色 -2- O:\75\75526-920603 DOC\ 7 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899 A BCDA8 i said · ΰ · B8:! Year G C8] D8 L______, patent application pixel sampling (SPS) luminance channel and one or more SPS chrominance channels; high-pass filter for high-pass filtering one or more of these An SPS chrominance channel; and a combination device for combining the one or more high-pass filtered SPS chrominance channels with the SPS luminance channel to form a lower resolution image with reduced errors. A computer-readable medium storing a method for converting a higher-resolution image into a lower-resolution image and reducing visible errors, the method includes the following actions: a higher-resolution contrast color gamut (opponent color domain; An OCD) image segmentation consists of an initial luminance channel and one or more initial chrominance channels; performing sub-pixel sampling on the initial luminance channel, thereby establishing an additive colo rdomain (ACD) luminance image; Converting the ACD luminance image into an OCD luminance image; segmenting the OCD luminance image into a pixel sampling (SPS) luminance channel and one or more SPS chrominance channels; high-pass filtering the one or more SPS chrominance channels ; And combining the one or more high-pass filtered SPS chrominance channels with the SPS luminance channel to form a lower resolution image with reduced errors. A method for converting a higher resolution image into a lower resolution image and reducing visible errors. The method includes the following actions: Segmenting a higher resolution contrast color domain (OCD) image into separate components. One starting brightness channel and several starting colors-2- O: \ 75 \ 75526-920603 DOC \ 7 This paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) 558899 A BCD

正充六、申請專利範圍度通道；對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive color domain ; ACD)亮度影像；將該ACD亮度影像轉換成一 OCD亮度影像；將該OCD亮度影像分割成分開的一次像素取樣（SPS) 亮度通道及數個SPS色度通道；高通濾波該等SPS色度通道；低通滤波該等起始色度通道；次取樣該等已濾波起始色度通道；組合該等次取樣、低通濾波色度通道與該等高通濾波 SPS色度通道；以及組合該等已組合色度通道與該SPS亮度通道，以構成一減少錯誤之較低解析度影像。 5. 如申請專利範圍第4項之方法，其中該較高解析度影像是一加色域影像，會先將該影像轉換成一對比色域影像，之後才會進行該分割一較高解析度OCD影像。 6. 如申請專利範圍第4項之方法，其中該加色域影像是一 RGB影像。 7. 如申請專利範圍第4項之方法，其中該對比色域影像是一 YCrCb影像。 8. 如申請專利範圍第4項之方法，其中該對比色域影像是一 LAB影像。 9. 如申請專利範圍第4項之方法，其中該高通濾波包括暈光蒙片（unsharp-mask)濾波。 O:\75\75526-920603 DOC\ 7 * 3 - 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐） 558899 A8 B8 C8 D8Positive charge 6. Apply for a patent range channel; perform sub-pixel sampling on the initial brightness channel to establish an additive color domain (ACD) brightness image; convert the ACD brightness image into an OCD brightness image; OCD luminance image segmentation consists of one pixel sampling (SPS) luminance channel and several SPS chrominance channels; high-pass filtering of these SPS chrominance channels; low-pass filtering of these initial chrominance channels; sub-sampling and filtering Starting chrominance channel; combining the sub-sampling, low-pass filtering chrominance channel and the high-pass filtering SPS chrominance channel; and combining the combined chrominance channel and the SPS luma channel to form a lower error reduction Resolution image. 5. If the method of the fourth item of the patent application is applied, wherein the higher resolution image is an additive color gamut image, the image will be converted into a contrast color gamut image before the segmentation of a higher resolution OCD image. . 6. The method according to item 4 of the patent application, wherein the color gamut image is an RGB image. 7. The method according to item 4 of the patent application, wherein the contrast color gamut image is a YCrCb image. 8. If the method of claim 4 is applied for, the contrast color gamut image is a LAB image. 9. The method according to item 4 of the patent application, wherein the high-pass filtering includes unsharp-mask filtering. O: \ 75 \ 75526-920603 DOC \ 7 * 3-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 558899 A8 B8 C8 D8

六、申請專利範圍 10·如申請專利範圍第4項之方法，其中該高通濾波包括下列動作：經由一具有一高斯（Gaussian)低通核心的暈光蒙片濾波器來滤波該等SPS色度通道，以產生低通SPS色度通道 :以及將該等SPS色度通道減去該等SPS低通色度通道，以產生高通濾波SPS色度影像。 11·如申請專利範圍第4項之方法，其中該等色度通道包括一紅色轉綠色通道以及一藍色轉黃色通道。 12.如申請專利範圍第4項之方法，其中該等色度通道包括一 YCrCb影像的Cr和Cb通道。 13_如申請專利範圍第4項之方法，其中該等色度通道包括一 CIELab影像的「a」和「b」通道。 14·如申請專利範圍第4項之方法，其中該方法進一步包括將該減少錯誤之較低解析度影像轉換成一 RGB影像。 15. 如申請專利範圍第4項之方法，其中該執行次像素取樣步驟包括將該起始亮度通道轉換成一加色域（ACD)亮度影像，並且取樣該ACD亮度影像。 16. —種用來以一減少可見錯誤之較低解析度來顯示一較高解析度影像的方法，該方法包括下列動作：將一較高解析度RGB影像轉換成一較高解析度對比色域（OCD)影像；將該較高解析度對比色域（0CD)影像分割成分開的_ 起始亮度通道及數個起始色度通道； O:\75\75526-920603 DOC\ 7 - 46. The scope of patent application 10. The method according to item 4 of the patent scope, wherein the high-pass filtering includes the following actions: filtering the SPS chroma through a halo mask filter having a Gaussian low-pass core. Channel to generate a low-pass SPS chrominance channel: and subtract the SPS chrominance channels from the SPS chrominance channels to generate a high-pass filtered SPS chrominance image. 11. The method according to item 4 of the patent application, wherein the chrominance channels include a red-to-green channel and a blue-to-yellow channel. 12. The method according to item 4 of the patent application, wherein the chrominance channels include Cr and Cb channels of a YCrCb image. 13_ The method of claim 4 in the scope of patent application, wherein the chrominance channels include the "a" and "b" channels of a CIELab image. 14. The method of claim 4, wherein the method further comprises converting the lower resolution image with reduced errors into an RGB image. 15. The method of claim 4, wherein the performing sub-pixel sampling step includes converting the starting luminance channel into an additive color gamut (ACD) luminance image, and sampling the ACD luminance image. 16. A method for displaying a higher resolution image at a lower resolution that reduces visible errors, the method including the following actions: converting a higher resolution RGB image into a higher resolution contrast color gamut ( OCD) image; segment the higher resolution contrast gamut (0CD) image into _ starting luminance channels and several starting chrominance channels; O: \ 75 \ 75526-920603 DOC \ 7-4

本紙張尺度適用_家鱗(⑽）A4規格_ χ挪公爱)This paper size is applicable _ Jiascale (⑽) A4 specifications _ χ Norwegian public love)

558899 A8 B8 C8 D8 六、申請專利範圍將該起始亮度影像轉換成一 RGB亮度影像；對該RGB亮度影像執行次像素取樣；將該次像素取樣（SPS)RGB亮度影像轉換成一 SPS-OCD亮度影像；將該SPS-OCD亮度影像分割成分開的一 SPS亮度通道及數個SPS色度通道；高通濾波該等SPS色度通道；低通濾波該較高解析度OCD影像的該等起始色度通道；次取樣該等已濾波起始色度通道；組合該等次取樣、低通濾波色度通道與該等高通濾波 SPS色度通道；組合該等已組合色度通道與該SPS亮度通道，以構成一減少錯誤之OCD較低解析度影像；以及將該一減少錯誤之OCD較低解析度影像轉換成一減少錯誤之較低解析度RGB影像。 17. —種用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤的方法，該方法包括下列步騾：將一較高解析度對比色域（opponent color domain ; OCD)影像分割成分開的一起始亮度通道及數個起始色度通道；對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive color domain ; ACD)亮度影像；將該ACD亮度影像轉換成一 OCD亮度影像；將該OCD亮度影像分割成分開的一次像素取樣（SPS) O:\75\75526-920603 DOC\ 7 - 5 - 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐) 558899558899 A8 B8 C8 D8 6. The scope of the patent application converts the starting brightness image into an RGB brightness image; performs sub-pixel sampling on the RGB brightness image; converts the sub-pixel sampling (SPS) RGB brightness image into an SPS-OCD brightness image ; An SPS luminance channel and several SPS chrominance channels that divide the SPS-OCD luminance image into components; high-pass filtering the SPS chrominance channels; low-pass filtering the initial chrominance of the higher-resolution OCD image Channel; sub-sampling the filtered starting chrominance channels; combining the sub-sampling, low-pass filtering chrominance channels and the high-pass filtering SPS chrominance channels; combining the combined chrominance channels and the SPS luma channel, Forming an OCD lower resolution image with reduced errors; and converting the OCD lower resolution image with reduced errors into a lower resolution RGB image with reduced errors. 17. A method for converting a higher-resolution image into a lower-resolution image and reducing visible errors, the method includes the following steps: a higher-resolution contrast color domain (OCD) image Segment a starting luminance channel and several starting chrominance channels; perform sub-pixel sampling on the starting luminance channel to establish an additive color domain (ACD) luminance image; and convert the ACD luminance image Converted into an OCD brightness image; One pixel sampling (SPS) of this OCD brightness image is divided into O: \ 75 \ 75526-920603 DOC \ 7-5-This paper standard is applicable to China National Standard (CNS) A4 specification (210 X (297 mm) 558899

A8 B8 C8 D8 々、申請專利範圍亮度通道及數個SPS色度通道；高通濾波該等SPS色度通道；低通濾波該等起始色度通道；次取樣該等已濾波起始色度通道；組合該等次取樣、低通濾波色度通道與該等高通濾波 SPS色度通道；以及組合該等已組合色度通道與該SPS亮度通道，以構成一減少錯誤之較低解析度影像。 18. —種用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤的系統，該系統包括：一第一分割器，用以將一較高解析度對比色域 (opponent color domain ; OCD)影像分割成分開的一起始亮度通道及數個起始色度通道；一次像素取樣器，用以對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive color domain ; ACD) 亮度影像；一轉換器，用以將該ACD亮度影像轉換成一OCD亮度影像；一第二分割器，用以將該OCD亮度影像分割成分開的一次像素取樣（SPS)亮度通道及數個SPS色度通道；一高通滤波器，用以高通滤波該等S P S色度通道；一低通濾波器，用以低通濾波該等起始色度通道；一次取樣器，用以次取樣該等已濾波起始色度通道；一第一組合器，用以組合該等次取樣、低通濾波色度 O:\75\75526-920603 DOC\ 7 - 6 _ 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐)A8 B8 C8 D8 々、 Patent application scope Luminance channel and several SPS chrominance channels; High pass filtering of these SPS chrominance channels; Low pass filtering of these starting chrominance channels; Sub-sampling of these filtered starting chrominance channels ; Combining the sub-sampling, low-pass filtered chrominance channels and the high-pass filtered SPS chrominance channels; and combining the combined chrominance channels and the SPS luminance channel to form a lower-resolution image with reduced errors. 18. A system for converting a higher-resolution image into a lower-resolution image and reducing visible errors, the system comprising: a first divider for comparing a higher-resolution contrast color gamut (opponent color domain; OCD) an initial luminance channel and several initial chrominance channels separated by a segment; a primary pixel sampler for performing sub-pixel sampling on the initial luminance channel, thereby establishing an additive color domain (domain; ACD) luminance image; a converter for converting the ACD luminance image into an OCD luminance image; a second divider for dividing the OCD luminance image into a one-time pixel sampling (SPS) luminance channel and Several SPS chrominance channels; a high-pass filter for high-pass filtering the SPS chrominance channels; a low-pass filter for low-pass filtering the initial chrominance channels; a sampler for sub-sampling The filtered initial chrominance channels; a first combiner for combining the sub-sampled, low-pass filtered chrominances O: \ 75 \ 75526-920603 DOC \ 7-6 _ This paper size is applicable to the Chinese national standard Standard (CNS) A4 (210 X 297 mm)

裝 558899 A BCD558899 A BCD

正充々、申請專利範圍通道與該等高通濾波SPS色度通道；以及一第二組合器，用以組合該等已組合色度通道與該 SPS亮度通道，以構成一減少錯誤之較低解析度影像。 19. 一種包括用以將一較高解析度影像轉換成一較低解析度影像且減少可見錯誤之指令的電腦可讀取媒體，該指令包括下列動作：將一較高解析度對比色域（opponent color domain ; OCD)影像分割成分開的一起始亮度通道及數個起始色度通道；對該起始亮度通道執行次像素取樣，藉此建立一加色域（additive color domain ; ACD)亮度影像；將該ACD亮度影像轉換成一 OCD亮度影像；將該OCD亮度影像分割成分開的一次像素取樣（SPS) 亮度通道及數個SPS色度通道；高通濾波該等SPS色度通道；低通濾波該等起始色度通道；次取樣該等已濾波起始色度通道；組合該等次取樣、低通濾波色度通道與該等高通濾波 SPS色度通道；以及組合該等已組合色度通道與該SPS亮度通道，以構成一減少錯誤之較低解析度影像。 O:\75\75526-920603 DOC\ 7 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐)Positive charging, patent-applied channels and the high-pass filtered SPS chrominance channels; and a second combiner for combining the combined chrominance channels and the SPS luminance channel to form a lower resolution that reduces errors image. 19. A computer-readable medium including instructions for converting a higher-resolution image into a lower-resolution image and reducing visible errors, the instruction including the following actions: comparing a higher-resolution contrast color gamut (opponent color (domain; OCD) image segmentation into an initial luminance channel and several initial chrominance channels; performing sub-pixel sampling on the initial luminance channel, thereby establishing an additive color domain (ACD) luminance image; Convert the ACD luminance image into an OCD luminance image; divide the OCD luminance image into one pixel sampling (SPS) luminance channel and several SPS chrominance channels; high-pass filter the SPS chrominance channels; low-pass filter the Starting chrominance channels; sub-sampling the filtered starting chrominance channels; combining the sub-sampling, low-pass filtering chrominance channels and the high-pass filtering SPS chrominance channels; and combining the combined chrominance channels and The SPS luminance channel constitutes a lower resolution image with reduced errors. O: \ 75 \ 75526-920603 DOC \ 7 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)