Fusion of global and local side information using Support Vector Machine in transform-domain DVC

Side information has a strong impact on the performance of Distributed Video Coding. Commonly, side information is generated using motion compensated temporal interpolation. In this paper, we propose a new method for the fusion of global and local side information using Support Vector Machine. The global side information is generated at the decoder using global motion parameters estimated at the encoder using the Scale-Invariant Feature Transform. Experimental results show that the proposed approach can achieve a PSNR improvement of up to 1.7 dB for a GOP size of 2 and up to 3.78 dB for larger GOP sizes, with respect to the reference DISCOVER codec. © 2012 EURASIP

Successive refinement of motion compensated interpolation for transform-domain distributed video coding

In distributed video coding, the estimation of the side information at the decoder plays a key role in the final ratedistortion performance of the codec. The side information is commonly generated by motion-compensated temporal interpolation of the neighboring reference frames. In this paper, we propose a successive refinement after the decoding of each DCT subband to improve the accuracy of motion compensation between reference frames, in order to obtain a new side information estimation closer to the originalWyner-Ziv frame. The experimental results show that the proposed scheme can achieve up to 0.9 dB of improvement in ratedistortion performance for a GOP size of 2 and 2.4 dB for a GOP size of 8 for sequences containing high motion with respect to state-of-the-art techniques. © EURASIP, 2011

Improved side information generation for distributed video coding

In distributed video coding, the side information is commonly generated by motion-compensated temporal interpolation of the neighboring reference frames at the decoder side. The side information quality has a strong impact on the final rate-distortion performance of the codec. In this paper, we propose a successive refinement after the decoding of each DCT subband to improve the accuracy of motion compensation between reference frames, in order to obtain a new side information estimation closer to the original Wyner-Ziv frame. Here, we propose two different algorithms in the refinement process of the side information. The experimental results show that the proposed techniques allow an improvement in rate-distortion performance that can reach 1.15 dB for GOP size of 2 and 3.2 dB for longer GOP size, with respect to state-of-the-art techniques, for sequences containing high motion. © 2011 IEEE

Fusion of global and local motion estimation for distributed video coding

The quality of side information plays a key role in distributed video coding. In this paper, we propose a new approach that consists of combining global and local motion compensation at the decoder side. The parameters of the global motion are estimated at the encoder using scale invariant feature transform features. Those estimated parameters are sent to the decoder in order to generate a globally motion compensated side information. Conversely, a locally motion compensated side information is generated at the decoder based on motion-compensated temporal interpolation of neighboring reference frames. Moreover, an improved fusion of global and local side information during the decoding process is achieved using the partially decoded Wyner-Ziv frame and decoded reference frames. The proposed technique improves significantly the quality of the side information, especially for sequences containing high global motion. Experimental results show that, as far as the rate-distortion performance is concerned, the proposed approach can achieve a PSNR improvement of up to 1.9 dB for a Group of Pictures (GOP) size of 2, and up to 4.65 dB for larger GOP sizes, with respect to the reference DISCOVER codec. © 1991-2012 IEEE

Successive refinement of side information using adaptive search area for long duration GOPs in distributed video coding

In distributed video coding, the reference frames are used to generate a side information at the decoder in order to decode the Wyner-Ziv frame. The quality of side information has a strong impact on the coding efficiency of distributed video coding. The estimation of the side information becomes less accurate when the temporal distance between the neighboring reference frames increases or when the sequence contains fast motion. In this paper, we propose a new method based on successive refinement of the side information by adapting the motion search area after decoding the first DCT band. More specifically, different search areas are initially set, according to the temporal distance between the neighboring reference frames. Furthermore, the size of the search area is adapted to the motion content after decoding the first DCT band by using the partially decoded Wyner-Ziv frame. This adapted search area is used in order to refine the side information after decoding each remaining DCT band. The experimental results show that the proposed technique allows an improvement in rate distortion performance that can reach 0.7 dB for a GOP size of 8, compared to the method where a constant search area is used, and a significant gain up to 3.23 dB, with respect to DISCOVER codec. The improvement in the quality of the final side information reaches 5.6 dB for some frames, compared to constant search area. Moreover, the proposed method reduces significantly the decoding time for all test sequences. © 2012 IEEE

Side Information improvement in transform-domain distributed video coding

Side Information (SI) has a strong impact on the rate-distortion performance in distributed video coding. The quality of the SI can be impaired when the temporal distance between the neighboring reference frames increases. In this paper, we introduce two novel methods that allow improving the quality of the SI. In the first approach, we propose a new estimation method for the initial SI using backward and forward motion estimation. The second one consists in re-estimating the SI after decoding all WZFs within the current Group of Pictures (GOP). For this purpose, the SI is first successively refined after each decoded DCT band. Then, after decoding all WZFs within the GOP, we adapt the search area to the motion content. Finally, each already decoded WZF is used, along with the neighboring ones, to estimate a new SI closer to the original WZF. This new SI is then used to reconstruct again the WZF with better quality. The experimental results show that, compared to the DISCOVER codec, the proposed method reaches an improvement of up to 3.53 dB in rate-distortion performance (measured with the Bjontegaard metric) for a GOP size of 8. © 2012 SPIE