TW200535686A - Decoder for BD-ROM, and method for generating image signals - Google Patents

Abstract

A decoder (50) is described for receiving and decoding an information stream which contains page composition information, region composition information, object data, and possibly colour look-up table indication information, and for generating image signals on the basis of said information, which information defines at least one page (60) in at least one plane of the contents of a display image. The decoder comprises: a colour look-up table memory (38) containing at least one colour look-up table (CLUT) having a colour look-up table ID; an object buffer (36) for storing decoded object data; a composition buffer (35) for storing page composition information, region composition information, and colour look-up table indication information; and an image controller (51) adapted to generate image signals (RGB+α) directly on the basis of the object data in the object buffer (36) and at least one colour look-up table (CLUT) in the colour look-up table memory (38), using the information in the composition buffer (35).

Description

200535686 IX. Description of the invention: [Technical field to which the invention belongs] The present invention is generally related to the field of displaying information on display screens such as monitors and televisions. More specifically, the present invention relates to a decoder in a display device, which has an input terminal that receives encoded information about video, subtitles, and graphics, and is designed to decode and process this information. More specifically, the present invention relates to reducing the size of the buffers used in these display devices: Method 0 has been based on various standards or formats (such as compact disc_standard, digital versatile disc (DVD) standard, etc.) A relatively new 'quasi-BD' (disc monitor) is issued for optical discs and disc players. Specifically, the present invention relates to the field of reading pre-recorded optical discs, and will be specifically described below: This exemplary application, however, should be noted that it is not intended to limit the scope of the present invention to BD-ROM. [Prior Art] It is well known that a movie (or other visual image) includes a series of continuously displayed pictures. Generally, each picture corresponds to At a display time of 40 ms (or in other words, a movie usually contains 25 pictures per second). This display time will also be called ', frame interval'. The display screen includes a pixel array arranged in horizontal rows and vertical columns. In digital video, provide information from the drive that reads the bd_ ROM disc to the display device in encoding mode. The display device receives the encoded information and calculates the entire information during the decoding process. The pixel information of the film is stored in the buffer memory. The actual process of displaying the corresponding picture includes reading 9985.doc 200535686 to fetch the buffer, calculate the continuous pixel driving signal, and continuously display the pixel driving signal to the camp screen. The pixels are written horizontally line by line and line by line from top to bottom. Since the techniques of encoding and decoding pictures and displaying pictures on the screen are already well known, they do not need to be described in more detail here. It should be noted that The important format for encoding pictures is the MPEG format. You can receive encoded information wirelessly, such as in the case of digital broadcasting. You can also obtain encoded poor information by reading storage media such as optical discs. Allowed A device that records itself on a writable w. Similarly, 'Audio Publishing Company or Video Publishing Company publishes a pre-recorded disc player' These discs are read-only discs (ROM); users can bet to play this The disc playback device (play_back apparatus). In this playback device (hereinafter simply referred to as the player), the disc player component reads and decodes the record. The material on the disc 'and generates a video stream and / or audio stream' The video stream and / or audio stream are suitable for display via a display device (such as a television device, monitor, speaker, etc.). Since the present invention does not involve Audio, so it will be ignored in the following discussions. A movie can contain several elements, which are explained as follows: Mobile cymbals, meaning actual pictures of a movie that is about to be shown on a TV screen. In the following, this is also referred to as a video picture Or main display image. Subtitles. Subtitles are graphic representations of text, which are graphically overlaid on the main display image like day, day, and day display. Subtitles are frame-accurate (meaning that they have a timing related to the timing of the main display ) And displayed during a specific time period. For example, subtitles are used to: '98915.doc 200535686-show translations of spoken text, and help people who have difficulty understanding the language of spoken text; °-show spoken The Transcript of Your Master's Transcript 'to help people with hearing difficulties;-Transcripts of verbal text for karaoke (singing) purposes;-Display notes; Graphic pictures. The graphic picture is also covered on the main display and the shirt like the π and the middle display. There is a difference between synchronous graphics and non-returning y /, non-paced graphics. Synchro frames are displayed with frame precision + m during special time periods. The same: ▲ graphics can contain static graphics or dynamic graphics, or a combination of the two. The graphic contains an image displayed during a number of main display frame intervals. For example, static graphics are used to:-display interactive buttons with button status descriptions (such as " normal ", " select " start ",etc.); dynamic graphics include-series are different from each other Each image is displayed in combination with—or multiple main display images. For example, motion graphics are used to:-display the director's comments;-emphasize parts of the main display image (for example, during the director's comments). Shapes are also displayed during specific time periods, but do not require precise timing. The same example as in the case of synchronized graphics is also applicable. The picture will be explained in more detail with reference to Figure 1. For this explanation, the concept of "planar" is introduced . The combination of several elements ® 1 shows the three pictures (images) placed behind each other, as if they were in a stack, meaning different, parallel, and flat. The bottom picture is video picture V; its image is 98915.doc 200535686; the upper picture is graphic picture G; the picture in the middle is subtitle picture. For common reference to these figures, the application plane will be referred to as the video plane. The most corresponding plane will be called the graphics plane. s, its corresponding plane will be called the subtitles and images "), and will use the phrase slice 'It is the final picture P (" Xian, Fansu ~ image. According to the meaning, the video plane contains " video image ", The subtitle plane s has a curtain image" and the graphics plane contains "graphic images". Each elementary shirt image V, S, G has a size corresponding to the display size of the display.

size of. In the case of high-definition television (HDTV), the size of the display is 1920 * 1080 pixels. For each pixel, a 3-color (RGB or γυν) value and a transparency level value are required. Transparency levels indicate blending with images from lower planes. The lowest level is not transparent. In the case of one byte per variable, 4 bytes per pixel are required. This results in larger memory. This is why the information in the plane is stored in an encoded manner. The amount of data required for each pixel in the plane depends on the encoding method. Video picture: 16 bits per pixel. The Ke Ke coding uses a sampling standard of [4: 2: 2 or 4: 2: 0]. Caption picture: 8-bit [color lookup table with 256 inputs, and each input has 4 bytes (RGB + alpha) graphic picture at the output end · 8-bit [color lookup table with 256 inputs , And each input has 4 bytes (RGB + alpha) at the output end, while reading the plane, perform 4 bytes per pixel conversion (RGB + alpha) 〇 By adding the corresponding video based on pixel by pixel , Subtitles and graphic images and test 98915.doc 200535686

Consider the alpha value indicating the transparency value to construct the final display image p. More specifically, 'amp' is to construct the RGB value of a pixel of the final display image p. Multiply the RGB value of the corresponding video pixel by a factor (1_as) (block 丨), and multiply the RGB value of the corresponding subtitle pixel by a factor as. (Block 2), and add the results of both (Block 3), multiply by the factor (1- 邶) (Block 4), multiply the result by (Block 5) and multiply the RGB value of the corresponding graphic pixel by (Block 6) The RGB value of the factor. Here, as defines the transparency value of the subtitle pixels, and does not define the transparency value of the graphics pixels. For example, if the transparency value ag of a graphic pixel is ag = 1, the graphic pixel is completely transparent (meaning invisible), and the pixels from the lower plane are completely visible; otherwise, if ag = = 0, then The graphic pixels are completely opaque, and pixels from lower planes are not visible. The (MPEG) transport stream can contain multiple subtitle services that are different from each other, such as different languages and different aspect ratios. Similarly, a transport stream can contain multiple graphics services that are different from each other and can be selected by the user. During playback, if selected by the user, only one of these subtitle services is decoded and displayed. Similarly, 'as selected by the user', only one of these graphics services is decoded and displayed. Due to the decoder model of the subtitle plane and graphics plane, the following description will only specifically refer to the subtitle plane. The subtitle service includes a plurality of consecutive subtitle pages, each of which has a size corresponding to the size of the sub-curtain plane (that is, horizontal blue pixels by vertical_pixels in the case). Each page is displayed for a specific duration. The duration usually corresponds to multiple video frame intervals. This period of time is called the page entity, and the content of the subtitle plane remains the same during one entity. The transport stream only contains information on the subtitle page, which is combined with the indication of the start and end time shown by 98915.doc 200535686. The area I ^ & describes the page combination of the page layout. Only one or more areas are returned, and the number can be identified or identified. For example, the rectangular area is indicated by the coordinates of two diagonal corners. During the actual period of the page, this is the only one that has pixels within this area on the page to the right of the page layout. The effect is the same as when considering all 1 pixels. The transparency value is 1 (completely transparent), but using the area saves calculation time. Tian Tian-All areas are within the page area. Two or more areas can be repeated C1: ’In the re-registered area, the right-clicker has one of the search areas (top area) for display. The area can point to objects such as photos, text files, and so on. Different areas can point to the same object, but each area points to only one object. Each object has an -object identifier number. The size of each object can be smaller or larger than the page size, but the size is sufficient to completely fill the area pointing to the object.

The subtitle and graphic information of the mpeg transport stream is transmitted in the following way. Use page composition segment (PCS) to describe page layout; use area composition segment to describe the nature of the area '· use object definition segment to describe objects; and make μ material umc: ujT ... one or more CLUT tables can be used in the page composition. Each segment is encapsulated in a pES packet, which contains a PTS / DTS timestamp. The PES packet, together with the D8 packet and pir ^ _, is packaged in a basic transport stream. The above is illustrated in Figures 2A and 2B. FIG. 2A shows a subtitle page 10 having two regions 丨 丨 and ^ which partially overlap, and the first region u overlays the second region 12. FIG. 2A further shows the two objects 13 and 14. The size of the first object 98915.doc -10- 200535686 13 is smaller than the size of the page 10; the vertical size of the second object "is larger than the page area 11 of the page pointing to a part 15 of the first object 13; the second area 12 is pointing to the first Part 16 of one of the two objects 14. Figure 2B illustrates the caption image in the caption plane, that is, the content of the caption page. The caption image is defined by the first area. The first portion 21 contains the portion of the first object 13. This caption The second knife 22s of the image defined by the second region 12 has a portion 16 of the first object 14. The remaining portion of this subtitle image μ is empty.

Objects are stored separately in the decoder. During page reconstruction, the decoder knows which object to read for every pixel in the page. For example, when reconstructing the first pixel A% decoding benefit in the first region u, the corresponding pixel A from the first object 13 will be used; when reconstructing the second pixel B in the second region 12, the decoder will use The corresponding pixel B from the second object 14; when the second pixel C in the area 23 that is not in any area is reconstructed, the decoder will set R = G = B = 0 (black). The advantage of this approach is that the objects need to be transmitted and demarcated only once. You can change the relative position of the area relative to the page (for example: the position of the rectangle u with respect to the page 1G) 'or change the relative position of the area with respect to the corresponding object (for example: the position of the rectangle 15 relative to the object 13). To achieve some kind of moving day. Fig. 3 is a phase diagram illustrating the timing of transmission, decoding and display. The horizontal axis represents time; the time unit indicates the frame interval. The action "Transfer" decoding, and, 'show,' means that the buckle is not a horizontal bar with a start time and an end time. 98915.doc 200535686 At time t1, t2, and t3, the data segment Ding Xinhehua is transmitted, which is about page combination (page combination segment), area combination (region combination segment), and color lookup table (CLUT segment). The page group segment contains information about, for example, the page's display time stamp (PTS), the number and location of regions, and overlapping relationships (hierarchical or mutual priority). The area combination segment contains information about, for example, the corresponding object (object ID) and the relative position of the area relative to the corresponding object. The CLUT segment contains a color lookup table CLUT with a CLUT-ID. Page combinations and / or area combinations can indicate which CLUT should be used for the corresponding page, area, and object. From time t4 to time t5, the first object data segment Td is transmitted. The data segment Td contains the data of the first object, a decoding time stamp, and a display daytime stamp (PTS). When decoding is started so that the object is decoded in time before it is displayed, and the display time stamp determines when the object should start to be displayed. As soon as all object data is received, the first object can be decoded (from time to t8, t6 is determined by DTS). As soon as the first object is decoded, the first object can be displayed (time 19 determined by P T S in the free page combination segment). From time t7 to time t10, data including the second object and the corresponding second object data segment Te of DTS and PTS are transmitted and received. Once all the object data is received, the second object can be decoded (from time 111 to 112, decision). As soon as the second object is decoded, the second object can be displayed (starting from the time tl 3 determined by the display timestamp in the page combination segment of the new page moment). The transition from displaying the first object to displaying the second object may include erasing and / or fading effects, so that the starting time 113 of displaying the second object is earlier than 98915.doc 12 200535686 showing the ending time of the first object t14 . The erasing and / or fading effect = the data segments Tf, Tg, and Th are executed at the time m, at the time m, and this is not the same as the page combination and area combination at time t13, U6, and t14. Figure 4 The design and operation of the decoder 30 according to the prior art will be explained. The packet filter (PID) filter 31 receives the data stream, and then temporarily stores the data in the transmission buffer 32 to average the bit rates. The transmission buffer can be relatively small, and a size of 512 bytes is sufficient. Next, the encoded data is stored in the encoded data buffer 33; therefore, the encoded data buffer 33 contains a subtitle segment as shown in FIG. At _ determined by the DTS of these segments, it is removed from the encoding buffer 33. The page combination section, the area combination section, and the color lookup table are transferred to the combination buffer 35 'and the object definition section is transferred to the graphics processor 34. The graphics processor 34 decodes the object segment, and the decoded object segment is stored in the object buffer 36. The PTS timestamp of a page combination segment indicates when the corresponding page will be displayed. The graphics controller 39 uses the information in the combination buffer 35 to update the area of the subtitle plane 37 with the information from the object buffer 36. Next, read out the subtitle plane with the same address as the video plane and graphics plane. "Use the color lookup table in the color lookup table memory 38 to translate the 8-bit data from the word plane 37 into 32 bits. (Four times 8-bit) RGB + a, which is provided as an output signal. One disadvantage of this known design is that whenever there is any change, such as when the area moves relative to the page or when the object moves relative to the area , 98915.doc 13 200535686 need to update the entire sub-screen thousand face 37 (including 1920 * 1080 pixels in the case of hd video). Update all the elements that can be read out on the sub-screen plane 37; another On the one hand, the update has been initiated when the subtitle plane 37 is read. At the same time, the update process is performed in a very short time interval relative to the vertical blanking period (blanking). Therefore, the bit rate between the object buffer and the subtitle plane 37 is very high. If this bit rate becomes too high, double buffering may even be required in the subtitle plane π, thus requiring twice the memory space In addition, the fact that the decoded objects are stored in the object buffer% and also in the subtitle plane 37 constitutes a disadvantage because it requires a relatively large amount of memory space. An important object of the present invention is to overcome or at least reduce the At least one of the disadvantages etc. [Abstract] According to an important aspect of the present invention, the step of filling the subtitle plane 37 is avoided based on the page combination data, area combination data, and object parameters. The image controller directly uses the Data. Therefore, the subtitle plane can be omitted to save memory space. If the pixels are outside the area, there is no need to address the corresponding pixels in the buffer, and the transparency can be set to furnace 1, so that its value is not important In particular, there is no need to refresh any “hidden body position” outside the area, and the corresponding transparency value α is not determined to be U fully transparent when providing the corresponding pixel output signal. [Embodiment] Figure 5 is the case A diagram illustrating the design and operation of the decoder 50 according to the present invention. 989l5.doc -14- 200535686 In the comparison of the solution of FIG. 5 $ 《Λ t 摅 本 ㈣ When compared with the known decoder 30 of Fig. 4, it can be seen that the decoder 50 of the root month does not contain any subtitle plane. The components 31_36 may

The same element as above is a ladder α > r J — and it needs to be explained again. The image controller 51 is > three storage page combination lean materials, area combination data and object parameters. When discriminating the output pixels, the image controller 51 obtains the correct pixel (s) from the correct position (s) of the correct object based on its known information, and the information includes the corresponding transparency value. Make pixels outside the area completely transparent (α = 1).

This avoids the need to provide image memory and the need to refresh this image memory at a very large bit rate. Looking more at Θ 6 Α and 6B, the operation of the decoder according to the present invention will be explained in more detail. The pixel address of the page will be defined in the rectangular coordinate system [x, y], the X coordinate corresponds to the horizontal position, and the y coordinate corresponds to the vertical position. The page has a size of 1920x1080 pixels. The upper left corner is [0, 〇], the upper right corner is [1919,0]; the lower left corner is [0,1079], and the lower right corner is [1919,1079]. Assume that the page combination data of a certain page 60 defines two regions 61 and 62. The upper left corner of the first region 61 having a horizontal width wl and a vertical height hl is located at [xl, yl] in the page. The upper left corner of the second area 62 having a horizontal width of ~ 2 and a vertical height h2 is located at [x2, y2] in the page. The second area 62 overlaps the first area 61. It is assumed that two objects 71 and 72 are stored in the object buffer 36. The first object 71 has a horizontal width Wobjl and a vertical height Hobjl; and the second object 72 has a horizontal width Wobj2 and a vertical height Hobj2. 98915.doc 200535686 The first area 61 points to the first object 71, where w0bjl2wl and Hobjlkhl. The second area 62 points to the second object 72, where wObj22w2 and Hobj22h2. The pixel address of the object will be defined in the rectangular coordinate system [p, q]. The p coordinate corresponds to the horizontal position and the q coordinate corresponds to the vertical position. The address [p = 05q = 0] corresponds to the upper left corner of the object. Suppose the upper left corner of the first region 61 points to the address [pl, ql] (meaning the address of the first object 71), and the upper left corner of the second region 62 points to the address [p2, q2] (meaning the second object Address 72). Since the objects 71, 72 should completely cover the areas 6 丨, 62 that point to it, the following restrictions apply:

Wobj 1 > p 1 + w 1 Hobj 1 > q 1 + h 1 Wobj2 > p2 + w2 Hobj2 &q; +2 flow chart. The display starts by selecting the pixel in the upper left corner [steps 丨 0 丨]. For this pixel, first determine whether the pixel is located in the "upper layer" area (meaning the second area 62), [step m]; if it is not in the second area 62, determine whether the pixel is located in the "lower layer" area (Meaning the first region 61) [step 121]. If the pixel is not in the first region 61, generate an RGB signal at an arbitrary value (for example, RG B-0) [step 131], and set the transparency level α [㈣132] 'indicates that this pixel is completely transparent. Because of this, in this case, you can consult the object buffer 36 and use the color lookup table from the color lookup table memory ^ to translate the pixel values into RGB signals 98915.doc -16- 200535686 If the pixel is found in the second area 62 in step 111, the corresponding pixel address in the object pointed to by the second area 62 (meaning the second object 72) is calculated [step 112], read the content of this address from the object buffer 36 [step 113], and use the color lookup table from the color lookup table memory 38 to turn it into an RGB signal [step 114], the color lookup table has As indicated by page composition and / or area combination information CLUT_m. In addition, set the transparency level α to the transparency level defined by the second area 62 [step 丨 M]. Right in step 121, it is found that the pixels are within the first area 6 丨, then the private objects in the area 61 are calculated. (Meaning the first object 71) the corresponding pixel address [step 122], read the content of this address from the object buffer% [step U3] 'and use the color lookup table from the color lookup table memory " It turns to ^ RGB ^ #b [step 124], and the color lookup table has the clut_id indicated by the page combination material and / or area combination information. In addition, the transparency level is set to the transparency level defined for the first area 61 [step 125]. In step 140, the pixel signals RGB and α are rotated out, which includes a combination with pixels from the appealing plane and the video plane, but this is not explained. Repeat the above procedure for all the pixels of ~ horizontal ：: Add the χ coordinate of the pixel [step 151] until it reaches the end of the line [step 152]. Repeat the above procedure for all lines of the image: the y-coordinate of the line increases-[step 161] until it reaches the end of the page [step 162]. At the end of the page, the above procedure starts again from the beginning to produce the next image frame. It should be noted that any of #page combination data, area combination data, or object parameters have been rewritten. The above description of the operation of the image controller 5 丨 still applies. 98915.doc -17- 200535686 Use j to set the second area 62 to the left Shift — pixels. In accordance with the solution of the prior art, [Zhongbei 1], the entire subtitle plane 37 is completely refreshed from the display pixel [1919, 1079] to the display material [0, 0] in the conversion period. In the solution according to the present invention, for the pixels outside the -p ^ ^ domain 62 (whether in its old position or in its new position), the above procedure yields exactly the same results. The same conclusion applies to pixels within the -F 0 ^ ^ ^ ^ domain 62 (whether in its old position or its new position). For images that are now within the second region M and previously outside the region 62, or are now outside the second region ^ and were previously within the second region 62, μ " That is, read pixel data from different positions of the object buffer 36 and / or have different values for the transparency level. ≫ It should be clear to those skilled in the art that the present invention is not limited to the above-mentioned illustrative examples. Several changes and amendments may be made within the scope of the present invention as defined by the scope of the attached patent application. For example, the combination, You Chongyi 35, and the image controller 51 can be integrated into a whole. In addition, the above The present invention has been described in the case where the image contains three planes covering each other, but the present invention is also applicable to one of the images: the case where there are more than three planes covering each other, and the invention even As in the case where the image contains only-or two planes. In the above, the invention has been described with reference to block diagrams, which illustrate = functional blocks of the device according to the invention. It should be understood that this can be in hardware In this specialized function block A lot of people who want to go to the basin where the function of this function block is performed by individual hardware / pieces, but it is also possible to construct these function blocks in software one or more times so that the function of this function block is controlled by a computer program_ or Multiple program lines 98915.doc 200535686 or programmable devices (such as microprocessors, microcontrollers, etc.) to execute. [Schematic description] # ° Figure 1 is a block diagram illustrating the picture structure as a combination of several elements Figures; Figures 2A and 2B are diagrams illustrating the construction of pictures using pages, regions, and objects; Figure 3 is a timing diagram illustrating the timing of transmitting, decoding, and displaying objects;

Fig. 4 is a diagram illustrating the design and operation of a decoder according to the prior art; Fig. 5 is a diagram illustrating the design and operation of a decoder according to the present invention; Figs. 6A and 6B are illustrations of the position of a page pixel with respect to an address within an object Generation of Addresses According to the Present Invention FIG. 7 is a flowchart illustrating operations of the image controller when performing a method of an image signal. [Description of main component symbols] 10 Subtitle page 11 First area 12 Second area 13 First object 14 Second object 15 First part 16 First part 21 First subtitle image 22 Second subtitle image 98915.doc • 19- 200535686

23 The remainder of the subtitle image 30 Prior art decoder 31 Packet identifier filter 32 Transmission buffer 33 Coded data buffer 34 Graphics processor 35 Combination buffer 36 Object buffer 37 Subtitle plane 38 Color look-up table 39 Graphics controller 50 Decoder of the present invention 51 Image controller 60 Page 61 First region 62 Second region 71 First object 72 Second object 100 Method 98915.doc -20-

Claims (1)

200535686 10. Scope of patent application · L: A kind of calcite horse ⑽ 'which is used to receive and decode — an information stream containing page combination information = area combination information, object data, and possibly color lookup table pointers ^ information, and Generating a plurality of image signals based on the information, the information defines at least one page in at least-plane of each content of the displayed image (60); the decoder comprises:-a color lookup table memory (38), which contains A color look-up table (Clut) with a color look-up table ID; _ an object buffer (36) for storing decoded object data; a combined buffer (35) for storing page combination information and area combination information, And color lookup table indication information; • an image controller (51) adapted to use the lean information in the combined buffer (35), based on the object data in the object buffer (36) and the color lookup table memory At least one color look-up table (CLUT) in the body (38) directly generates a plurality of image signals (RGB + c0. 2. The decoder of the item 1 of Ruming, wherein the image controller (51) is displaying the mental image for the display When a certain pixel (χ, y) in a certain plane generates several image signals (RGB + α), it is adapted to: (determine whether the pixel (X, y) is located in one of a region (61; 62) In the visible part (steps 111, 121); (b) in the event that the pixel (X, y) is not in one of the visible parts of any area (61; 62), several pixels are generated for this pixel with 0ί = 1 (fully transparent) Output the pixel signal (RGB + ce) (step 132). 3. As in the decoder of claim 2, in case the pixel (χ, y) is not in any visible part of the region 98915.doc 200535686 domain (61, 62) In this image controller ⑺) is adapted to have R = G = B, etc. to the range of-any constant and preferably equal to zero. This pixel generates a number of output pixel signals (RGB + a) (step 131) 〇4 The decoder of the request, wherein when the image controller (51) generates several image signals (RGB + α) for a certain pixel (χ, y) of a certain plane of the display image, it is adapted to: ⑷ Determine whether the pixel (X, 7) is located in the visible part of the area (62) '(step 111); (0 in case the pixel (X y) located in a visible part of an area (62), (d) the object buffer (36) reads the object data; (e) based on the object data read from the object buffer (36), this pixel A number of output pixel signals (RGB + α) are generated. 5. The decoder of Ruming term 4, wherein the image controller u is adapted to take into account the relative position of the area (62) relative to the page (60) ( χ2, y2) and _ 忒 region (62) relative position (p2, q2) with respect to the object (72), the object (72) pointed by the region (62) where the pixel (X, y) is located A corresponding address is read from the object buffer (36). 6. The decoder of Ruyi seeking item 5, wherein the image controller (51) is adapted to the address of the 4 object (72) (ρ = ρ2 + (χ-χ2), q = q2 + (y-y2) w Read the object data from the object buffer (36).