Patent Publication Number: US-2010118940-A1

Title: Adaptive reference picture data generation for intra prediction

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/925,351, filed Apr. 19, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to communications systems and, more particularly, to video coding and decoding. 
     In typical video compression systems and standards, such as MPEG-2 and JVT/H.264/MPEG AVC (e.g., see ITU-T Rec. H.264, “Advanced video coding for generic audiovisual services”, 2005), encoders and decoders generally rely on intra frame prediction and inter frame prediction in order to achieve compression. With regard to intra frame prediction, various methods have been proposed to improve intra frame prediction. For example, displaced intra prediction (DIP) and template matching (TM) have achieved good coding efficiency for texture prediction. The similarity between these two approaches is that they both search the previously encoded intra regions of the current picture being coded (i.e., they use the current picture as a reference) and find the best prediction according to some coding cost, by performing, for example, region matching and/or auto-regressive template matching. 
     SUMMARY OF THE INVENTION 
     We have observed that both displaced intra prediction (DIP) and template matching (TM) encounter similar problems that degrade coding performance and/or visual quality. Specifically, the reference picture data from previously coded intra regions of the current picture may contain some blocky or other coding artifact, which degrades coding performance and/or visual quality. However, we have also realized that it is possible to address the above-described coding performance problems with regard to intra coding. In particular, and in accordance with the principles of the invention, a method for encoding comprises the steps of generating adaptive reference picture data from previously coded macroblocks of a current picture; and predicting uncoded macroblocks of the current picture from the adaptive reference picture data. 
     In an embodiment of the invention, a device incorporates an H.264 compatible video encoder for providing compressed, or encoded, video data. The H.264 encoder comprises a buffer for storing previously coded macroblocks of a current picture being encoded; and a processor for generating adaptive reference picture data from the previously coded macroblocks of the current picture; wherein the adaptive reference picture data is for use in predicting uncoded macroblocks of the current picture. 
     In another embodiment of the invention, a device incorporates an H.264 compatible video decoder for providing video data. The H.264 decoder comprises a buffer for storing previously coded macroblocks of a current picture being decoded; and a processor for generating adaptive reference picture data from the previously coded macroblocks of the current picture; wherein the adaptive reference picture data is for use in decoding macroblocks of the current picture. 
     In view of the above, and as will be apparent from reading the detailed description, other embodiments and features are also possible and fall within the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 to 8  illustrate prior art video encoding and decoding for intra frame prediction using DIP or TM; 
         FIG. 9  shows an illustrative device in accordance with the principles of the invention; 
         FIG. 10  shows an illustrative block diagram of an H.264 encoder in accordance with the principles of the invention; 
         FIG. 11  shows another illustrative block diagram of a video encoder in accordance with the principles of the invention; 
         FIG. 12  shows Table One illustrating the different types of processing in accordance with the principles of the invention; 
         FIG. 13  shows Table Two illustrating a high-level syntax for use in the device of  FIG. 9  or the H.264 encoder of  FIG. 10 ; 
         FIGS. 14 and 15  show other illustrative block diagrams of a video encoder in accordance with the principles of the invention; 
         FIG. 16  shows an illustrative flow chart for use in a video encoder in accordance with the principles of the invention; 
         FIG. 17  shows another illustrative device in accordance with the principles of the invention; 
         FIGS. 18 and 19  show illustrative block diagrams of a video decoder in accordance with the principles of the invention; 
         FIG. 20  shows an illustrative flow chart for use in a video decoder in accordance with the principles of the invention; and 
         FIGS. 21 to 26  show other illustrative embodiments in accordance with the principles of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Other than the inventive concept, the elements shown in the figures are well known and will not be described in detail. Also, familiarity with video broadcasting, receivers and video encoding is assumed and is not described in detail herein. For example, other than the inventive concept, familiarity with current and proposed recommendations for TV standards such as NTSC (National Television Systems Committee), PAL (Phase Alternation Lines), SECAM (SEquential Couleur Avec Memoire) and ATSC (Advanced Television Systems Committee) (ATSC) is assumed. Likewise, other than the inventive concept, transmission concepts such as eight-level vestigial sideband (8-VSB), Quadrature Amplitude Modulation (QAM), and receiver components such as a radio-frequency (RF) front-end, or receiver section, such as a low noise block, tuners, demodulators, correlators, leak integrators and squarers is assumed. Similarly, other than the inventive concept, formatting and encoding methods (such as Moving Picture Expert Group (MPEG)-2 Systems Standard (ISO/IEC 13818-1)) and, in particular, H.264: International Telecommunication Union, “Recommendation ITU-T H.264: Advanced Video Coding for Generic Audiovisual Services,” ITU-T, 2005, for generating bit streams are well-known and not described herein. In this regard, it should be noted that only that portion of the inventive concept that is different from known video encoding is described below and shown in the figures. As such, H.264 video encoding concepts of pictures, frames, fields, macroblocks, luma, chroma, Intra frame prediction, Inter frame prediction, etc., is assumed and not described herein. For example, other than the inventive concept, intra frame prediction techniques such as spatial direction prediction, and those currently proposed for inclusion in extensions of H.264 such as displaced intra prediction (DIP) and template matching (TM) techniques, are known and not described in detail herein. It should also be noted that the inventive concept may be implemented using conventional programming techniques, which, as such, will also not be described herein. Finally, like-numbers on the figures represent similar elements. 
     Turning briefly to  FIGS. 1-8 , some general background information is presented. Generally, and as known in the art, a picture, or frame, of video is partitioned into a number of macroblocks (MBs). In addition, the MBs are organized into a number of slices. This is illustrated in  FIG. 1  for a picture  10 , which comprises three slices  16 ,  17 ,  18 ; where each slice includes a number of MBs as represented by MB  11 . As noted above, for intra frame prediction, the techniques of spatial direction prediction, displaced intra prediction (DIP) and template matching (TM) can be used to process the MBs of picture  10 . 
     A high-level representation of a prior art H.264-based encoder  50  is shown in  FIG. 2  for use in intra frame prediction using either DIP or TM proposed extensions to H.264 (hereafter simply referred to as encoder  50 ). As such, other modes supported by an H.264 encoder are not described herein. An input video signal  54  is applied to encoder  50 , which provides an encoded, or compressed, output video signal  56 . It should be observed that encoder  50  comprises video encoder  55 , video decoder  60 , and reference picture buffer  70 . In particular, encoder  50  duplicates the decoder processing so that both encoder  50  and a corresponding H.264-based decoder (not shown in  FIG. 2 ) will generate identical predictions for subsequent data. Thus, encoder  50  also decodes (decompresses) the encoded output video signal  56  and provides decoded video signal  61 . As shown in  FIG. 2 , the decoded video signal  61  is stored in reference picture buffer  70  for use in the prediction of subsequent encoded MBs in either the DIP or TM intra frame prediction techniques. It should be noted that either DIP or TM operate on a MB-basis, i.e., reference picture buffer  70  stores a MB, which is used for prediction of the subsequent encoded MBs. For completeness, a more detailed block diagram of prior art encoder  50  is shown in  FIG. 3 , the elements and operation of which are known in the art and are not described further herein. It should be noted that encoder control  75  is shown in dotted line form to represent control of all elements in  FIG. 3  in a simplified fashion (versus showing individual control/signaling paths between encoder control  75  and the other elements of  FIG. 3 ). In this regard, it should be noted that during DIP or TM intra frame prediction, each decoded MB is provided via signaling path  62  to reference picture buffer  70  via switch  80  (which is under the control of encoder control  75 ). In other words, each previously coded MB is not processed by deblocking filter  65 . A more simplified view of the data flow in a encoder  50  when performing DIP or TM intra frame prediction is shown in  FIG. 4 . Similarly, a corresponding prior art H.264-based decoder  90  is shown in  FIG. 5  for use in intra frame prediction using either DIP or TM proposed extensions to H.264. Again, a simplified form is shown in  FIG. 6  when H.264-based decoder  90  is performing DIP or TM intra frame prediction. 
     As noted above, an extension of an H.264 encoder may perform DIP or TM intra frame prediction. DIP intra frame prediction is illustrated in  FIG. 7  for a picture  20  at a point in time, T, in the intra frame encoding process (e.g., see, S.-L. Yu and C. Chrysafis, “New Intra Prediction using Intra-Macroblock Motion Compensation”, JVT meeting Fairfax, doc JVT-C151, May 2002; and J. Balle, and M. Wien, “Extended Texture Prediction for H.264 Intra Coding”, VCEG-AE11.doc, January 2007). As noted above, DIP is implemented on a MB basis. At time T, region  26  of picture  20  has been encoded, i.e., region  26  is an intra coded region; and region  27  of picture  20  is not yet encoded, i.e., uncoded. In DIP, a previously encoded MB is referenced by a displacement vector to predict the current MB. This is illustrated in  FIG. 7 , where previously encoded MB  21  is referenced by displacement vector (arrow)  25  to predict current MB  22 . The displacement vectors are encoded differentially using a prediction by the median of the neighboring blocks, in analogy to the inter motion vectors of H.264. 
     In a similar fashion, TM is illustrated in  FIG. 8  for a picture  30  at a point in time, T, in the intra frame encoding process (e.g., see, T. K. Tan, C. S. Boon, and Y. Suzuki, “Intra Prediction by Template Matching”, ICIP 2006; and J. Balle, and M. Wien, “Extended Texture Prediction for H.264 Intra Coding”, VCEG-AE11.doc, January 2007). Like DIP, TM is implemented on a MB basis. At time T, region  36  of picture  30  has been encoded, i.e., region  36  is an intra coded region; and region  37  of picture  30  is not yet encoded, i.e., uncoded. In TM, self-similarities of image regions are exploited for prediction. In particular, the TM algorithm recursively determines the value of the current pixel (or target) by searching the intra coded region for a similar neighborhood of pixels. This is illustrated in  FIG. 8 , where the current MB,  43 , the target, has an associated neighborhood (or template),  31 , of surrounding coded MBs. Intra coded region  36  is then searched to identify a similar candidate neighborhood, here represented by neighborhood  32 . Once a similar neighborhood has been located, then, as illustrated in  FIG. 8 , MB  33  of the candidate neighborhood is used as the candidate MB for predicting the target, MB  43 . 
     As noted earlier, both DIP and TM have achieved good coding efficiency for texture prediction. The similarity between these two approaches is that they both search the previously encoded intra regions of the current picture being coded (i.e., they use the current picture as a reference) and find the best prediction according to some coding cost, by performing, for example, region matching and/or auto-regressive template matching. Unfortunately, both DIP and TM encounter similar problems that degrade coding performance and/or visual quality. Specifically, the reference picture data stored in reference picture buffer  70  from previously coded intra regions of the current picture (e.g., intra region  26  of  FIG. 7  or intra region  36  of  FIG. 8 ) may contain some blocky or other coding artifact, which degrades coding performance and/or visual quality. However, it is possible to address the above-described coding performance problems with regard to intra coding. In particular, and in accordance with the principles of the invention, a method for encoding comprises the steps of generating adaptive reference picture data from previously coded macroblocks of a current picture; and predicting uncoded macroblocks of the current picture from the adaptive reference picture data. 
     An illustrative embodiment of a device  105  in accordance with the principles of the invention is shown in  FIG. 9 . Device  105  is representative of any processor-based platform, e.g., a PC, a server, a personal digital assistant (PDA), a cellular telephone, etc. In this regard, device  105  includes one or more processors with associated memory (not shown). Device  105  includes an extended H.264 encoder  150  modified in accordance with the inventive concept (hereafter referred to as encoder  150 ). Other than the inventive concept, it is assumed that encoder  150  conforms to ITU-T H.264 (noted above) and also supports the above-mentioned intra frame prediction techniques of displaced intra prediction (DIP) and template matching (TM) proposed extensions. Encoder  150  receives a video signal  149  (which is, e.g., derived from input signal  104 ) and provides an encoded video signal  151 . The latter may be included as a part of an output signal  106 , which represents an output signal from device  105  to, e.g., another device, or network (wired, wireless, etc.). It should be noted that although  FIG. 9  shows that encoder  150  is a part of device  105 , the invention is not so limited and encoder  150  may be external to device  105 , e.g., physically adjacent, or deployed elsewhere in a network (cable, Internet, cellular, etc.) such that device  105  can use encoder  150  for providing an encoded video signal. For the purposes of this example only, it is assumed that video signal  149  is a real-time video signal conforming to a CIF (Common Intermediate Format) video format. 
     An illustrative block diagram of encoder  150  is shown in  FIG. 10 . Illustratively, encoder  150  is a software-based video encoder as represented by processor  190  and memory  195  shown in the form of dashed boxes in  FIG. 10 . In this context, computer programs, or software are stored in memory  195  for execution by processor  190 . The latter is representative of one or more stored-program control processors and does not have to be dedicated to the video encoder function, e.g., processor  190  may also control other functions of device  105 . Memory  195  is representative of any storage device, e.g., random-access memory (RAM), read-only memory (ROM), etc.; may be internal and/or external to encoder  150 ; and is volatile and/or non-volatile as necessary. Other than the inventive concept, encoder  150  has two layers as represented by video coding layer  160  and network abstraction layer  165  as known in the art. In this regard, video coding layer  160  of encoder  150  incorporates the inventive concept (described further below). Video coding layer  160  provides an encoded signal  161 , which comprises the video coded data as known in the art, e.g., video sequence, picture, slice and MB. Video coding layer.  160  comprises an input buffer  180 , an encoder  170  and an output buffer  185 . The input buffer  180  stores video data from video signal  149  for processing by encoder  170 . Other than the inventive concept, described below, encoder  170  compresses the video data in accordance with H.264 as described above, and provides compressed video data to output buffer  185 . The latter provides the compressed video data as encoded signal  161  to the network abstraction layer  165 , which formats the encoded signal  161  in a manner that is appropriate for conveyance on a variety of communications channels or storage channels to provide H.264 video encoded signal  151 . For example, network abstraction layer  165  facilitates the ability to map encoded signal  161  to transport layers such as RTP (real-time protocol)/IP (Internet Protocol), file formats (e.g., ISO MP4 (MPEG-4 standard (ISO 14496-14)) for storage and Multimedia Messaging (MMS)), H.32X for wireline and wireless conversational services), MPEG-2 systems for broadcasting services, etc. 
     An illustrative block diagram of video encoder  160  for use in intra frame Prediction in accordance with the principles of the invention is shown in  FIG. 11 . For the purposes of this example, it is assumed that video encoder  160  performs either DIP or TM intra frame prediction for a current picture. As such, other modes supported by video coding layer  160  in accordance with the H.264 standard are not described herein. Video coding layer  160  comprises video encoder  55 , video decoder  60 , reference picture buffer  70  and reference processing unit  205 . An input video signal  149 , representing the current picture, is applied to video encoder  55 , which provides an encoded, or compressed, output signal  161 . The encoded output signal  161  is also applied to video decoder  60 , which provides decoded video signal  61 . The latter represents a previously coded MB of the current picture and is stored in reference picture buffer  70 . In accordance with the principles of the invention, reference processing unit  205  generates adaptive reference picture data (signal  206 ) from the previously coded MB picture data stored in reference picture buffer  70  for the picture currently being coded (i.e., the current picture). It is this adaptive reference picture data that is now used in the prediction of subsequent encoded MBs in either the DIP or TM intra frame prediction techniques for the current picture. Thus, reference processing unit  205  can filter the previously coded MB picture data to remove or mitigate any blocky or other coding artifacts. 
     Indeed, reference processing unit  205  can apply any one of a number of filters to generate different adaptive reference picture data. This is illustrated in Table One of  FIG. 12 . Table One illustrates a list of different filtering or processing techniques that reference processing unit  205  can use to generate the adaptive reference picture data. Table One illustrates six different processing techniques, referred to herein generally as “filter types”. In this example, each filter type is associated with a Filter_Number parameter. For example, if the value of the Filter_Number parameter is zero, then reference processing unit  205  uses a median-type filter to process the previously coded MB picture data stored in reference picture buffer  70 . Similarly, if the value of the Filter_Number parameter is one, then reference processing unit  205  uses a deblocking filter to process the previously coded MB picture data stored in reference picture buffer  70 . This deblocking filter is similar to deblocking  65  of  FIG. 3  as specified in H.264. As indicated in Table One, a customized filter type can also be defined. 
     It should be noted that Table One is just an example, and reference processing unit  205  can apply any one of a filter, transformation, warping, or projection on the data stored in reference picture buffer  70  in accordance with the principles of the invention. Indeed, the filters used to generate the adaptive reference picture data can be any spatial filter, median filter, Wiener filtering, Geometric Mean, Least Square etc. In fact, one can use any linear and nonlinear filter that could be used to remove the coding artifacts of the current (reference) picture. It is also possible to consider temporal methods, such as temporal filtering of previously coded pictures. Likewise, warping can be an affine transform or other linear and nonlinear transform which allows a better match of the currently to be coded intra block. 
     If reference processing unit  205  uses more than one type of filter, then a reference index is also used to associate the filter type with particular adaptive reference picture data produced by reference processing unit  205 . Turning now to  FIG. 13 , an illustrative reference list is shown in Table Two in accordance with the principles of the invention. Table Two represents an illustrative syntax for conveying information to an H.264 decoder. This information is conveyed in the high level syntax of H.264, e.g.; a sequence parameter set, a picture parameter set, a slice header, etc. For example, see section 7.2 of the above-mentioned H.264 standard. In Table Two, the parameter filter_number [i] specifies the filter type for i th  reference; the parameter num_of_coeff_minus — 1 plus 1 specifies the number of coefficients; and the parameter quant_coeff [j] specifies the quantized value of the j th  coefficient. The Descriptors u( 1 ), ue(v) and se(v) are defined as in H.264 (e.g., see section 7.2). For example, u( 1 ) is an unsigned integer of 1 bit; ue(v) is an unsigned integer Exp-Golomb-coded syntax element with the left bit first, where the parsing process for this descriptor is specified in section 9.1 of the H.264 standard; and se(v) is a signed integer Exp-Golomb-coded syntax element with the left bit first, where the parsing process for this descriptor is specified in section 9.1 of the H.264 standard. 
     As described above, an encoder or other device may apply multiple different filters to a reference picture data from the current picture being encoded. The encoder can use one or more of the filter types for performing intra frame prediction of the current picture. For example, the encoder may create a first reference for the current picture that uses a median filter. The encoder may also create a second reference that uses a geometric-mean filter, and create a third reference that uses a Wiener filter, etc. In this way, an implementation may provide an encoder that adaptively determines which reference (which filter) to use for any given MB, or region, of the current picture. The encoder may, for example, use a median filter reference for the first half of the current picture, and use a geometric-mean filter reference for the second half of the current picture. 
     For completeness, a more detailed block diagram of video coding layer  160  in accordance with the principles of the invention is shown in  FIG. 14 . Other than the inventive, the elements shown in  FIG. 14  represent an H.264-based encoder as known in the art and are not described further herein. It should be noted that encoder control  77  is shown in dotted line form to represent control of all elements in  FIG. 14  in a simplified fashion (versus showing individual control/signaling paths between encoder control  77  and the other elements of  FIG. 14 ). In this regard, it should be noted that during DIP or TM intra frame prediction, each decoded MB is provided via signaling path  62  to reference picture buffer  70  via switch  80  (which is under the control of encoder control  77 ). In accordance with the principles of the invention, encoder control  77  additionally controls switch  85  for providing adaptive reference picture data  206  and, if more than one processing technique is available, the selection of the Filter Type for use by reference processing unit  205 . A more simplified view of the data flow in video coding layer  160  when performing DIP or TM intra frame prediction in accordance with the principles of the invention is shown in  FIG. 15 . 
     Referring now to  FIG. 16 , an illustrative flow chart in accordance with the principles of the invention is shown for use in video coding layer  160  of  FIG. 10  for performing intra frame prediction of at least one picture, or frame, of video signal  149  of  FIG. 10 . Generally, and as known in the art, the current picture (not shown) is partitioned into a number of macroblocks (MBs). In this example, it is assumed that displaced intra prediction (DIP) is used for intra frame prediction. Similar processing is performed for TM in accordance with the principles of the invention and, as such, is not described herein. As noted above, DIP is implemented on a macroblock basis. In particular, in step  305 , initialization occurs for the intra frame prediction of the current picture. For example, the number of MBs, N, for the current picture is determined, a loop parameter, i, is set equal to 0, (where 0≦i&lt;N) and a reference picture buffer is initialized. In step  310 , the value of the loop parameter, i, is checked to determine if all of the MBs have been processed, in which case the routine exits, or ends. Otherwise, for each MB steps  315  to  330  are executed to perform intra frame prediction for the current picture. In step  315 , the reference picture buffer is updated with data from the i th −1 coded MB. For example, the data stored in the reference picture buffer represents the uncoded pixels from the i th −1 DIP coded MB. In step  330 , and in accordance with the principles of the invention, adaptive reference picture data, MB i−1   α , is generated from the i th −1 coded MB, as described above (e.g., see reference processing unit  205  of  FIG. 11  and Table One of  FIG. 12 ). In steps  325  and  330 , DIP is performed and searches for the best reference index (step  325 ) using the adaptive reference picture data, MB i−1   α , and, once found, encodes the i th  MB with the best reference index (step  330 ). 
     Turning now to  FIG. 17 , another illustrative embodiment of a device  405  in accordance with the principles of the invention is shown. Device  405  is representative of any processor-based platform, e.g., a PC, a server, a personal digital assistant (PDA), a cellular telephone, etc. In this regard, device  405  includes one or more processors with associated memory (not shown). Device  405  includes extended H.264 decoder  450  modified in accordance with the inventive concept (hereafter referred to as decoder  450 ). Other than the inventive concept, it is assumed that decoder  450  conforms to ITU-T H.264 (noted above) and also supports the above-mentioned intra frame prediction techniques of displaced intra prediction (DIP) and template matching (TM) proposed extensions. Decoder  450  receives an encoded video signal  449  (which is, e.g., derived from input signal  404 ) and provides a decoded video signal  451 . The latter may be included as a part of an output signal  406 , which represents an output signal from device  405  to, e.g., another device, or network (wired, wireless, etc.). It should be noted that although  FIG. 17  shows that decoder  450  is a part of device  405 , the invention is not so limited and decoder  450  may be external to device  405 , e.g., physically adjacent, or deployed elsewhere in a network (cable, Internet, cellular, etc.) such that device  405  can use decoder  450  for providing an decoded video signal. 
     For completeness, a more detailed block diagram of decoder  450  in accordance with the principles of the invention is shown in  FIG. 18 . Other than the inventive, the elements shown in  FIG. 18  represent an H.264-based decoder as known in the art and are not described further herein. Decoder  450  performs in a complementary fashion to that of video coding layer  160 , described above. Decoder  450  receives an input bitstream  449  and recovers therefrom an output picture  451 . It should be noted that decoder control  97  is shown in dotted line form to represent control of all elements in  FIG. 18  in a simplified fashion (versus showing individual control/signaling paths between decoder control  97  and the other elements of  FIG. 18 ). In this regard, it should be noted that during DIP or TM intra frame prediction, each decoded MB is provided via signaling path  462  to reference picture buffer  70  via switch  80  (which is under the control of decoder control  97 ). In accordance with the principles of the invention, decoder control  97  additionally controls switch  485  for providing adaptive reference picture data  206  and, if more than one processing technique is available, the selection of the Filter Type for use by reference processing unit  205 . It should be recalled that if more than one filter type exists, decoder  450  retrieves the reference list from, e.g., a received slice header, to determine the filter type. A more simplified view of the data flow in decoder  450  when performing DIP or TM intra frame prediction in accordance with the principles of the invention is shown in  FIG. 19 . 
     Referring now to  FIG. 20 , an illustrative flow chart in accordance with the principles of the invention is shown for use in decoder  450  of  FIG. 17 . The flow chart of  FIG. 20  is complementary to that show in  FIG. 16  for encoding the video signal. Again, it is assumed that displaced intra prediction (DIP) is used for intra frame prediction. Similar processing is performed for TM in accordance with the principles of the invention and, as such, is not described herein. As noted above, DIP is implemented on a macroblock basis. In particular, in step  505 , initialization occurs for the intra frame prediction of the current picture. For example, the number of MBs, N, for the current picture is determined, a loop parameter, i, is set equal to 0, (where 0 23  i&lt;N) and a reference picture buffer is initialized. In step  510 , the value of the loop parameter, i, is checked to determine if all of the MBs have been processed, in which case the routine exits, or ends. Otherwise, for each MB steps  515  to  530  are executed to perform intra frame prediction for the current picture. In step  515 , the reference picture buffer is updated with data from the i th −1 coded MB. For example, the data stored in the reference picture buffer represents the uncoded pixels from the i th −1 DIP coded MB. In step  520 , and in accordance with the principles of the invention, adaptive reference picture data, MB i−1   α , is generated from the i th −1 coded MB, as described above (e.g., see reference processing unit  205  of  FIG. 18 , Table One of  FIG. 12  and Table Two of  FIG. 13 ). It should be recalled that if more than one filter type exists, decoder  450  retrieves the reference list from, e.g., a received slice header, to determine the filter type. In step  530 , the MB is decoded in accordance with DIP. 
     Other illustrative embodiments in accordance with the principles of the invention are shown in  FIGS. 21 to 26 .  FIGS. 21 to 23  show other encoder variations. As can be observed from Table One of  FIG. 12 , reference processing unit  205  can include a deblocking filter. As such, separate deblocking filter  65  can be removed from the encoder and the deblocking filter of reference processing unit  205  can be used in its place. This variation is shown in encoder  600  of  FIG. 21 . An additional modification to encoder  600  is shown in encoder  620  of  FIG. 22 . In this embodiment, reference picture buffer  70  is eliminated and reference processing unit  205  operates in real-time, i.e., on-the-fly. Finally, the embodiment illustrated by encoder  640  of  FIG. 23  illustrates use of deblocking filter  65  for all MBs. Typically, as known in the art, deblocking filter  65  is used after a whole slice and/or picture is finished decoding (i.e., on a slice-basis and/or picture-basis not on a MB basis) or on single MB. In contrast, encoder  640  uses the deblocking filter for all MBs. As such, reference processing unit  205  is removed. Turning now to  FIGS. 24 to 26 , these figures illustrate similar modifications to decoders. For example, decoder  700  of  FIG. 24  is similar to encoder  600  of  FIG. 21 , i.e., the deblocking filter of reference processing unit  205  is used in place of a separate deblocking filter. Decoder  720  of  FIG. 25  is similar to encoder  620  of  FIG. 22 , i.e., reference picture buffer  70  is eliminated and reference processing unit  205  operates in real-time, i.e., on-the-fly. Finally, decoder  740  of  FIG. 26  is similar to encoder  640  of  FIG. 23 , i.e., the deblocking filter is used for all MBs. 
     As described above, and in accordance with the principles of the invention, adaptive reference picture data is adaptively generated for use in intra prediction. It should be noted that although the inventive concept was illustrated in the context of an DIP and/or TM extension of H.264, the inventive concept is not so limited and is applicable to other types of video encoding. 
     In view of the above, the foregoing merely illustrates the principles of the invention and it will thus be appreciated that those skilled in the art will be able to devise numerous alternative arrangements which, although not explicitly described herein, embody the principles of the invention and are within its spirit and scope. For example, although illustrated in the context of separate functional elements, these functional elements may be embodied in one or more integrated circuits (ICs). Similarly, although shown as separate elements, any or all of the elements may be implemented in a stored-program-controlled processor, e.g., a digital signal processor, which executes associated software, e.g., corresponding to one or more of the steps shown in, e.g.,  FIGS. 16 and 20 , etc. Further, the principles of the invention are applicable to other types of communications systems, e.g., satellite, Wireless-Fidelity (Wi-Fi), cellular, etc. Indeed, the inventive concept is also applicable to stationary or mobile receivers. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.