A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819--829, June 2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....In this work, we consider a combination of FEC and ARQ to add robustness to the wireless transmission, while trying to maximize the system throughput and support the notion of application level fairness in a wireless cellular data network. While similar schemes have been considered earlier [9] [10], 11] 12] the interaction between different QoS requirements are not considered and there still exist some problems that are not addressed properly in the previous work. One problem is that the fairness in the wireless area is neither well defined nor well solved when FEC coding is used to ....

....error and success failure history for the flow. Depending on the algorithm, the FEC estimator may be non adaptive or adaptive. It is important to note that in this work, we use the FEC generation itself as a black box, and use the FEC estimator merely to specify how much FEC is required [9] [10] [12] Given an application rate r i for flow i, the FEC overhead estimator generates fec i (r i ) the actual rate of the flow after the FEC is generated and incorporated into the flow. The utility curve based weights generator module takes the output of the first two modules as its input, and ....

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A. E.Mohr, E. A.Riskin and R. E.Ladner, "Unequal Loss Protection: Graceful Degradation of Image Quality over Packet Erasure Channels throught Forward Error Correction," in DCC, March 1999.

....description coding schemes have been investigated over the years. For an overview see [18] A particularly efficient and practical system is based on layered audio or video coding [29] 23] Reed Solomon coding [37] priority encoded transmission [3] and optimized bit allocation [15] 32] [25]. In such a system the audio and or video signal is partitioned into groups of frames (GOFs) each group having a duration of T 1 second or so, for example. Each GOF is then independently encoded, error protected, and packetized into M packets, as shown in Figure 2 and elaborated in Section ....

....where p(m) is the probability that m out of M packets are received. Given p(m) and the operational rate distortion function D(fl) this expected distortion can be minimized using a simple procedure that adjusts the rate points R, rim subject to a constraint on the packet length [15] 32] [25] 6. By assigning the ruth packet in each GOF to the ruth description, the entire audio and or video signal is represented by M descriptions, where each description is a sequence of packets transmitted at rate 1 packet per GOF. It is simple to generate these optimized 5Layered coding is also known ....

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal Loss Protection: Graceful Degradation of Image Quality over Packet Erasure Channels through Forward Error Correction. IEEE J. Selected Areas in Communications, 18(6):819 829, June 2000.

.... can be undertaken to face this problem, e.g. embedding error resilience tools in the compression algorithms, such as resynchronization markers or robust entropy encoding [1, 2] or resorting to joint source and channel coding [3] In this paper we adopt the joint source channel coding paradigm [4, 3, 5]. In particular, we consider the scenario of image transmission over packet networks subject to congestion. We assume that all packets formed from the image bitstream share the same priority within a given session, i.e. no packet hierarchy exists. Moreover, we focus on Unequal Loss Protection ....

....that consists in assigning a variable level of error protection to the source stream according to the importance of the information symbols. Most of the existing ULP algorithms are designed ad hoc for a given application or system. An interesting and fairly general framework has been proposed in [5]. In that scheme, the source symbols are fragmented and accommodated in the rows of an interleaver, with different amounts of Reed Solomon (RS) codes allocated to each fragment; packets are then formed columnwise. An algorithm is provided to compute the best allocation of source and code symbols ....

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A. Mohr, E. Riskin, R. Ladner, "Unequal loss protection: graceful degradation of image quality over packet erasure channels through foward error correction", IEEE Journal on Selected Areas in Communications, vol. 18, n. 6, pp. 81982.

....Several multiple description coding schemes have been investigated over the years. For an overview see [6] A particularly ecient and practical system is based on layered audio or video coding [15, 7] Reed Solomon coding [21] priority encoded transmission [1] and optimized bit allocation [4, 16, 8]. In such a system the audio and or video signal is partitioned into groups of frames (GOFs) each group having duration T = 1 second or so. Each GOF is then independently encoded, error protected, and packetized into M packets, as shown in Figure 1. If any m M packets are received, then the ....

....) where p(m) is the probability that m out of M packets are received. Given p(m) and the operational distortion rate function D(R) this expected distortion can be minimized using a simple procedure that adjusts the rate points R1 ; RM subject to a constraint on the packet length [4, 16, 8]. By sending the mth packet in each GOF to the mth description, the entire audio and or video signal is represented by M descriptions, where each description is a sequence of packets transmitted at rate 1 packet per GOF. It is a very simple matter to generate these optimized M descriptions on ....

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819-829, June 2000.

.... di#erent importance, such as I frames and P frames of MPEG data, di#erent layers of multi resolution description of media data, UEP codes have naturally been proposed to protect data loss and or corruption during transmission to improve the quality of data delivery in many applications, such as [16, 21]. The main goal of the UEP codes in these schemes is to deal with the data loss error during transmission. In contrast, the scheme proposed in this paper uses the UEP codes mainly to address the asynchronous issue of user requests over multicast networks with e#cient use of system resources. Data ....

A.E. Mohr, E.A. Riskin and R.E. Ladner, "Unequal Loss Protection: Graceful Degradation of Image Quality Over Packet Erasure Channels Through Forward Error Correction", IEEE Journal of Selected Areas in Communications Special Issue on Error-Resilient Image and Video Transmission, 18(6), 819-828, 2000.

....of MPEG video, and they did not optimize the code rates K n N to minimize the end to end distortion for a given overall transmission rate. Davis and Danskin [7] showed how to perform this optimization for any number of layers, using a simple slopematching algorithm. Mohr, Riskin, and Ladner [8] showed, in addition, how to adjust the breakpoints between layers when each GOF is encoded with a finely embedded source coder. However, they used a greedy search algorithm for this purpose. Puri and Ramchandran [9] showed how to solve this latter problem optimally (to within a relaxation ....

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819--829, June 2000.

....UEP FEC codes are applied to data that has been subjected to lossy compression, the measure of importance in determining the application of the UEP redundancy is usually the quality of the reconstruction. In general terms, the UEP approach tends to perform better than ELP in terms of quality [4], since one can better optimize the UEP placement so as to maximize the quality of the reconstruction of the data. This project investigates the FEC protection of object based codings. Specifically, we explore the assignment of UEP to objects of a multimedia dataset with the goals that each object ....

.... 26 27 28 29 30 31 32 2 3 4 5 6 7 T R E A M S F F F F F F F F F F Figure 1: Packet arrangement for UEP F represents an FEC code byte, while data bytes are numbered according to their occurrence in the embedded bitstream; packets are columns and streams are rows (adapted from [4]) 2.4 Reed Solomon Codes Reed Solomon codes are block based error correcting codes with a wide range of applications in digital communications. In these erasure codes, k blocks of source data are encoded to produce n blocks to be transmitted such that any subset of k encoded blocks is ....

[Article contains additional citation context not shown here]

A. E. Mohr, E. A. Riskin, and R. E. Ladner, "Unequal Loss Protection: Graceful Degradation of Image Quality Over Packet Erasure Channels Through Forward Error Correction," IEEE Journal on Selected Areas in Communications, vol. 18, no. 6, pp. 819--828, June 2000.

....correction, according to priorities specified by user, to message fragments. Recently the combination of progressive image coders with unequal error protection has been successfully e mail: stockhammer ei.tum.de, Tel: 49 89 28923474 combined for transmission over packet lossy networks, e.g. [7]. The combination of scalable video coding in combination with unequal erasure protection to combat Internet packet losses was introduced in [8] Progressive video codecs like the MPEG 4 FGS [9] and the Progressive Texture Video Codec (PTVC) 10] combined with unequal erasure protection show ....

....phenomenon within the GOP. 3. UNEQUAL ERASURE PROTECTION SCHEME We present a framework which utilizes the properties of progressive source coders and unequal erasure protection (UXP) schemes for the transmission over a lossy packet network. Similar work has been proposed previously in [6] and [7]. For all progressive source coders including the PTVC in general each additional bit improves the quality of a message at the decoder. Therefore, in contrast to the Priority Encoding Transmission (PET) introduced in [6] we allow a fragmentation of the total message at any symbol boundary. The ....

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A.E. Mohr, E.A. Riskin, and R.E. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE Journal on Selected Areas in Communications, vol. 18, no. 6, pp. 819--828, June 2000.

....It employs unequal error protection (UEP) to enhance the decoded mesh quality. Recent research efforts in transmission of multimedia objects over unreliable links are limited to still images and video sequences where different pre and post processing techniques have been investigated thoroughly [5]. Furthermore, current research efforts in 3 D graphics community are mainly limited to compression and mesh simplification [1] 6] Not many research efforts have been undertaken to stream out 3 D graphics except for MPEG 4 related research. The error resilience algorithm provided by MPEG 4 is ....

A. E. Mohr, E. A. Riskin, and R. E. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE Journal on Selected Areas in Communications, vol. 18, no. 6, pp. 819--828, June 2000.

No context found.

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819--829, June 2000.

....and overhead. Reed Solomon codes are used in most of the experiments here, because they are convenient to analyze and are flexible. However, we also include experiments with a simple repetition code that gives results with a very low latency at the expense of a higher and less flexible rate. In [36], a ULP algorithm was designed to assign unequal amounts of FEC to compressed image data. The ULP algorithm was designed for embedded codes, i.e. codes which allow intermediate reconstructions of the image from any prefix of the bitstream, and hence the ULP algorithm always assigns more FEC to ....

....AND F INDICATES AN ERROR CORRECTION BIT When speech MFCC vectors are encoded using tree structured VQ [33] the code is also embedded; thus, the ULP algorithm can be conveniently applied to ASR data. The open question is how much FEC should be assigned to the MFCC vectors. Whereas the work in [36] optimized a peak signal to noise ratio, here we assign FEC to minimize the WER. The assignment of FEC avoids catastrophic failure by gradually reducing the quality of the reconstructed speech vectors. Similar to the image coding work, when packet loss occurs, the WER performance will degrade ....

[Article contains additional citation context not shown here]

A. E. Mohr, E. A. Riskin, and R. E. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE J. Select. Areas Commun., vol. 18, no. 6, pp. 819--828, June 2000.

....Box 3822 Seattle, WA 89124 alanl trustedmedianetworks.com Abstract We study the application of Unequal Loss Protection (ULP) algorithms to motioncompensated video over lossy packet networks. In particular, we focus on streaming video applications over the Internet. The original ULP framework [15] applies unequal amounts of forward error correction (FEC) to embedded data to provide graceful degradation of quality in the presence of increasing packet loss. In this paper, we apply the ULP framework to baseline H.263, a video compression standard that targets low bit rates, by ....

....at high rates [3, 16] and a study by Boyce [6] on the e ects of packet loss on the quality of MPEG video shows that those high loss rates can severely damage video quality due to the temporal dependencies inherent in motion compensated video coders. The Unequal Loss Protection (ULP) framework [15] was developed to provide graceful degradation of quality in the presence of increasing packet loss. Graceful degradation provides a user with reduced but acceptable quality in proportion to the amount of data lost. The ULP framework accomplishes this by applying unequal amounts of forward error ....

[Article contains additional citation context not shown here]

Alexander E. Mohr, Eve A. Riskin, and Richard E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE Journal on Selected Areas in Communication, 18(6):819-829, June 2000.

....ASR server to perform speech recognition. Little attention in the ASR community has been paid to packet loss in the communication channel. In contrast, the image coding community has been studying the problem and numerous successful solutions that assign FEC to the coded image have been developed [8, 2, 3]. One approach to dealing with packet loss in ASR is to use interpolation to fill in the missing frames [7] but this may not be effective for bursts of loss. Here, we propose an alternative approach that accepts a small increase in transmission rate to introduce an error correction code. In this ....

....such as wireless networks or the Internet. In an (N; k) Reed Solomon code, N k symbols of FEC are used to protect k symbols of data, meaning that N symbols of data in total are transmitted. As long as any k of the N symbols are received, the k original symbols of data can be recovered. In [8], an unequal loss protection (ULP) algorithm was designed to assign unequal amounts of FEC to compressed image data. The ULP algorithm was designed for embedded codes, which allow intermediate reconstructions of the image from any beginning part of the bitstream and hence it always assigns more ....

[Article contains additional citation context not shown here]

A. Mohr, E. Riskin, and R. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE Journal on Selected Areas in Communications, 18(6):819--828, June 2000.

No context found.

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819--829, June 2000.

No context found.

Mohr A.E., Riskin E.A. and Ladner R.E., Unequal Loss Protection: Graceful Degradation of Image Qualityover Packet Erasure Channels Through Forward Error Correction, IEEE Journal on SelectedAreas in Communications,vol. 18, pp. 819828, June 2000.

No context found.

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal Loss Protection: Graceful Degradation of Image Quality over Packet Erasure Channels through Forward Error Correction. IEEE J. Select. Areas Commun., 18(6):819-828, 2000.

No context found.

A. E. Mohr, E. A. Riskin, and R. E. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE Journal on Selected Areas of Communications, vol. 18, pp. 819--828, June 2000.

No context found.

A.E. Mohr, E.A. Riskin and R.E. Ladner, \Unequal Loss Protection: Graceful Degradation of Image Quality Over Packet Erasure Channels Through Forward Error Correction", IEEE Journal of Selected Areas in Communications Special Issue on Error-Resilient Image and Video Transmission, 18(6), 819-828, 2000.

No context found.

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819--829, June 2000.

No context found.

A. Mohr, E. Riskin, and R. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE Journal on Selected Areas in Communications 18, pp. 819--828, June 2000.

No context found.

A. Mohr, E. Riskin, and R. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE Journal on Selected Areas in Communications, vol. 18, no. 6, pp. 819--828, June 2000.

No context found.

A. E. Mohr, E. A. Riskin, and R. E. Ladner. Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction. IEEE J. Selected Areas in Communications, 18(6):819-829, June 2000.

No context found.

A. E. Mohr, E. A. Riskin and R. E. Ladner, "Unequal Loss Protection: Graceful Degradation of Image Quality over Packet Erasure Channels through Forward Error Correction," IEEE J. Select. Areas Comm., 18(6), June 2000, pp. 819-828.

No context found.

A.E. Mohr, E.A. Riskin, and R.E. Ladner, "Unequal loss protection: Graceful degradation of image quality over packet erasure channels through forward error correction," IEEE J. Select. Areas Commun., vol. 18, pp. 819-828, June 2000.

No context found.

A. Mohr, E. Riskin, and R. Ladner, "Unequal loss protection: graceful degradation of image quality over packet erasure channels through forward error correction," IEEE Journal on Selected Areas in Communications, vol. 18, pp. 819-828, June 2000.

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