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..., they exhibit a graceful-degradation behavior and thus often yield similar or better performance for strongly distorted channels than the combination of strong source and channel encoding (e.g., [6]–=-=[8]-=-). On the other hand, postprocessing error concealment methods have become part of most decoders for noisy environments and channels with erasures [9]–[12]. Techniques applicable to blockwise transmis...

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...on codes. Due to the growing importance in rich multimedia data transmission, unequal error protection methods have attracted research efforts, see e.g. [23] and the references therein. For example, (=-=[22, 23]-=-) irregular repeat accumulate (IRA) codes [20] of different rates are designed and applied for scalable image transmission over binary symmetric channel (BSC). The different rates are obtained by punc...

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... amount of introduced redundancy to the significance of the source bits. For scalable multimedia transmission, this approach usually involves two steps: rate-compatible channel code design [14], [25]–=-=[27]-=- and UEP optimization algorithms [28]–[31]. The former provides different levels of error protection for source bits by puncturing the same mother code at different degrees; the latter performs optima...

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..., the data bits are grouped according to some criteria capable of determining their importance to the restored source data, and the different channel codes are assigned to different source bit groups =-=[4]-=- [5] [6]. In recognition of the fact that the effects of bit errors in encoded sources are usually more detrimental in some bit groups than in others, several UEP schemes for image transmission using ...

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...tion codes. Due to the growing importance in rich multimedia data transmission, unequal error protection methods have attracted research efforts, see e.g. [12] and the references therein. For example =-=[11, 12]-=- irregular repeat accumulate (IRA) codes [9] of different rates are designed and applied for scalable image transmission over binary symmetric channel (BSC). The different rates are obtained by punctu...

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...frame into subsets of varying quality lends itself naturally to employing a UEP scheme, in which the base layer is better protected than the enhanced layers. Examples of this approach can be found in =-=[45, 46]-=-. Our work in Chapter 6, where transmission power is allocated to a single layer of video packets according to their error sensitivity, can also be classified into this category. In channel-optimized ...

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...5], [23]. In the second approach, transmitted packets have all the same length (L1 = … = LN = L) and thus depending on 23 n isthe channel coding rate, source packets would have different lengths [2], =-=[3]-=-, [22]. Although the algorithm of [2] has been designed for the latter scenario, we notice that one may apply it equally effectively to the former. The only difference is that the final nodes of the s...

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...rmation and the decoding of satisfactory quality images. A variety of error-resilient techniques for transmission of images over error-prone channels have been recently proposed in the literature. In =-=[1]-=-, irregular repeat accumulate codes (IRA) [2] were proposed for the transmission of JPEG2000 and SPIHT streams over Binary Symmetric Channels (BSC). The scheme in [1] showed performance superior to th...

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... Arizona, Tucson, AZ 85721 USA. He is now with Thomson, Inc., Corporate Research, Princeton, NJ 08540 USA. Digital Object Identifier 10.1109/TIP.2006.888329 the distortion in reconstructed images. In =-=[7]-=-, the authors consider the design of punctured irregular repeat-accumulate codes, and their application to a UEP scheme for scalable image and video coders. In [8], the authors investigate the design ...