1394 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 15, NO. 11, NOVEMBER 2005 A Robust Error Concealment Technique Using Data Hiding for Image and Video Transmission Over Lossy Channels Chowdary B. Adsumilli, Student Member, IEEE, Mylène C. Q. Farias, Member, IEEE, Sanjit K. Mitra, Life Fellow, IEEE, and Marco Carli, Senior Member, IEEE Abstract—A robust error concealment scheme using data hiding which aims at achieving high perceptual quality of images and video at the end-user despite channel losses is proposed. The scheme involves embedding a low-resolution version of each image or video frame into itself using spread-spectrum watermarking, extracting the embedded watermark from the received video frame, and using it as a reference for reconstruction of the parent image or frame, thus detecting and concealing the transmission errors. Dithering techniques have been used to obtain a binary watermark from the low-resolution version of the image/video frame. Multiple copies of the dithered watermark are embedded in frequencies in a specific range to make it more robust to channel errors. It is shown experimentally that, based on the frequency selection and scaling factor variation, a high-quality watermark can be extracted from a low-quality lossy received image/video frame. Furthermore, the proposed technique is compared to its two-part variant where the low-resolution version is encoded and transmitted as side information instead of embedding it. Simulation results show that the proposed concealment technique using data hiding outperforms existing approaches in improving the perceptual quality, especially in the case of higher loss proba- bilities. Index Terms—Data hiding, digital half-toning, error conceal- ment, image/video transmission, wireless video. I. INTRODUCTION T HE transmission of images and video over wired and/or wireless channels introduces multiple losses into the transmitted data that manifest themselves as various types of artifacts. These artifacts degrade the quality of the received image/video as they vary rapidly during the course of trans- mission based on the channel conditions. Therefore, there is a need for a good error concealment technique that can detect and correct (or conceal) these errors better and display a good quality image/video regardless of the channel conditions [1]. In the case of video transmission over wireless channels, adaptive Manuscript received September 3, 2003; revised March 6, 2004. This work was supported in part by the National Science Foundation under Grant CCR- 0105404, the University of California under a MICRO grant, Philips Research Laboratories, and Microsoft Corporation. This paper was recommended by As- sociate Editor L. Onural. C. B. Adsumilli, M. C. Q. Farias, and S. K. Mitra are with the Depart- ment of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106–9560 USA (e-mail: chowdary@ece.ucsb.edu; mylene@ece.ucsb.edu; mitra@ece.ucsb.edu). M. Carli is with the Department of Applied Electronics, University of Rome Tre, Rome 00146, Italy (e-mail: carli@uniroma3.it). Digital Object Identifier 10.1109/TCSVT.2005.856933 error control that adapts to the approaches both at the trans- mitter and at the receiver has proven to be more effective [2]. Error concealment methods use spatial and temporal informa- tion to recognize that an error has occurred. Once an error is de- tected, the received video stream is adjusted with an attempt to recover the original data. A number of error concealment tech- niques have been proposed in the literature that use either sta- tistical methods to detect and correct errors (these are usually computationally intensive) or depend on certain critical infor- mation from the transmitter, like the resynchronization markers, to detect these transmission errors. In this paper, a new robust error concealment algorithm which uses watermarking is proposed. Watermarking is usually used to introduce some redundancy to the transmitted data with little increase in its bit rate during implementation [3]. The basic idea of the proposed algorithm is as follows. A frame of a video is wavelet transformed and the low–low approximation coefficients (usually second- or third-order) are then embedded in the frame itself during MPEG encoding. The embedded data can then be error protected unequally such that the mark signal embedded packets are given higher protection against channel errors. At the receiver, the mark is extracted from the decoded frame. The channel corrupted information of the frame is then reconstructed using the embedded mark signal. Specific areas lost through transmission are selected from the reconstructed mark signal and replaced in the original frame, thus enhancing its perceptual quality. 1 This contribution provides modified algorithms for implementation in video transmission and high-detail color extensions in case of wired and wireless transmission scenarios. Also, a comparison of the proposed technique to its two-part variant (where the low-resolution child image is encoded and transmitted as side information) is provided along with an extensive analysis of its performance. The paper is organized as follows. Section II briefly points out the previous work in error concealment where similar/re- lated approaches have been addressed. Section III describes the proposed error concealment/reconstruction algorithm using data hiding. Section IV gives a detailed explanation of the multiple scenarios under which the algorithm can be modified to make it more efficient. The simulations done using the proposed technique and the obtained results are presented in 1 Preliminary results of the performance of the algorithm’s implementation for wired transmission of images have been partially reported [4]. 1051-8215/$20.00 © 2005 IEEE