P. Salama, N. Shroff, and E. J. Delp, "A bayesian approach to error concealment in encoded video streams," in Int. Conf. Image Processing, vol. 2, Lausanne, Switzerland, Sept. 1996, pp. 49--52.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... range information forerrorconcealment [17] 18] Anextensiontotheassumption thatnaturalimages are smooth and the values are continuous spatially or spectrally is to adopt the Markov random fields (MRF)to model the images [19] MRF based error concealment methods were first proposedby Salama et al.[20] [22] LaterShirani et al. 23]proposedtoadaptively adjust the MRF model parameters but not to increase the model order and showed that the adaptive MRF outperforms MRFmethods.MultiscaleMRF(MMRF)by Zhang and Ma [24] is another extension of MRF.MMRF models imageblocks insteadof imagepixels.Work by ....

P.Salama,N. Shroff, andE.J.Delp, A Bayesianapproach to errorconcealment in encoded video streams, ICIP 1996, vol.1,pp.49-52.

....for concealment. Spatial EC methods [5] 7] 9] 14] 16] 20] 22] 26] 28] 30] 42] are mainly targeted for intra frame concealment ranging from simple bilinear interpolation ones to complex fuzzy reasoning based ones. Temporal methods [6] 7] 12] 16] 20] 22] 26] 28] [31], 33] 37] 38] 40] 43] 48] can be used for both inter and intra coded concealment provided that temporal information is available. Spatiotemporal methods [5] 6] 15] 16] 22] 33] 49] 50] are based on measures of spatial and temporal activity for determining the type of ....

P. Salama, N. Shroff, and E.J. Delp, "A bayesian approach to error concealment in encoded video streams", in Proc. of 1996 Int. Conf. on Image Processing, 1996, vol. 2, pp. 49--52.

....its neighboring slices kept intact. In [47] each frame is split into four bands and the data for each band packed together. This distributes the error due to cell loss over the entire frame, rather than localize it. Post processing techniques for the sake of error concealment are addressed in [48, 49, 46, 50, 51, 52, 53, 54, 55, 56, 57]. In [48, 49, 46] it is assumed that partial loss of DCT coe#cients has occurred. High frequency coe#cients that have been lost are replaced by zeros. The remaining coe#cients are estimated, by minimizing a cost function. The cost function is the sum, over all pixels in a block, of the square of ....

....to have entire rows of macroblocks missing. In this case, spatial interpolation will not yield acceptable reconstructions. However, the motion vectors of the surrounding regions can be used to estimate the lost vectors, and the damaged region reconstructed via motion compensated interpolation [54, 55, 56]. Let X be an N 1 N 2 decompressed frame from an MPEG sequence and let Y be the received version at the output of the channel. Due to channel errors it is conceivable that Y may have missing data. Each transmitted picture consists of M macroblocks that have NN pixels. Let x i be the ....

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P. Salama, N. Shro#, and E. J. Delp, "A bayesian approach to error concealment in encoded video streams," Proceedings of the International Conference on Image Processing, vol. II, September 16--19 1996, Lausanne, Switzerland, pp. 49--52.

....in the channel. When digital video is transmitted over these networks one must be able to reconstruct the missing data so that the impact of these errors is minimized. In this paper we describe a Bayesian approach to concealing these errors by post processing the received data. In a prior paper [1], each frame in the sequence was modeled as a Markov Random Field, and maximum a posteriori estimates of the missing macroblocks were obtained. However, the maximum a posteriori estimate is not unique, and the algorithm is also computationally intensive. In this paper we demonstrate, that by ....

....under Grant No. NCR 9624525. Address all correspondence to E. J. Delp, ace ecn.purdue.edu, http: www.ece.purdue.edu #ace, or 1 765 494 1740. A postscript version of this paper is available at ftp: skynet.ecn.purdue.edu pub dist delp icip97 errcon. namely spatial and temporal interpolation [1 5]. In spatial interpolation, missing pixel values are reconstructed from neighboring spatial information, whereas in temporal interpolation the lost data is reconstructed from past and future frames. In [1] the concealment of lost macroblocks resulting from ATM cell loss was addressed using a ....

[Article contains additional citation context not shown here]

P. Salama, N. Shro#, and E. J. Delp, "A bayesian approach to error concealment in encoded video streams," Proceedings of the International Conference on Image Processing, September 16--19 1996, Lausanne, Switzerland, pp. 49--52.

....it is possible to have entire rows of macroblocks missing. In this case, spatial interpolation will not yield acceptable reconstructions. However, the motion vectors of the surrounding regions can be used to estimate the lost vectors, and the damaged region reconstructed via temporal interpolation [33, 34]. Let X be an N 1 N 2 decompressed frame from an MPEG sequence and let Y be the received version at the output of the channel that may have missing data. Each transmitted picture consists of M macroblocks that have N N pixels . Let x i be the lexicographic ordering of the i th macroblock in X. ....

P. Salama, N. Shro#, and E. J. Delp, "A bayesian approach to error concealment in encoded video streams," Proceedings of the International Conference on Image Processing, September 16--19 1996, Lausanne, Switzerland, pp. 49--52.

....Recovered errors. In [8, 9] several spatial and temporal techniques for the reconstruction of missing data from MPEG sequences are discussed. Each frame is modeled as a Markov Random Field, and a maximum a posteriori (MAP) estimate of the missing macroblock data and motion vectors is obtained [10]. A nearly optimal spatial approach that approximates the MAP estimate of each missing pixel by the median of its neighbors was presented in [11] In our work, this nearly optimal technique is implemented for spatial concealment using a DSP. 2. ERROR CONCEALMENT ON THE TMS320C6201 DSP 2.1 Spatial ....

P. Salama, N. B. Shroff, and E. J. Delp, "A bayesian approach to error concealment in encoded video streams," Proceedings of the International Conference on Image Processing, September 16-19, 1996, Lausanne, Switzerland, pp. 49-52.

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P. Salama, N. Shroff, and E. J. Delp, "A bayesian approach to error concealment in encoded video streams," in Int. Conf. Image Processing, vol. 2, Lausanne, Switzerland, Sept. 1996, pp. 49--52.

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