Error resiliency issues in wavelet compression

Summary form only given. Error resiliency is the ability to tolerate uncorrectable errors with graceful quality degradation. It differs from traditional uses of error-correcting coding (ECC) in two major respects: (1) it assigns differentiated (rather than uniform) error protection to different segments of the data, and (2) if errors cannot be corrected in some data segments, a good- (albeit degraded-) quality reconstruction of the data is still possible. The error resiliency approach is suitable in lossy compression, particularly, DCT-based and wavelet-based compression. Under those compression schemes, the data is separated into different frequencies or frequency bands. Since the human visual and auditory systems are more sensitive to lower-frequency data than to higher-frequency data, it is better to protect the lower-frequency data more than the higher-frequency data, given a constant ECC bit rate. With this differentiated error protection, the probability of recovering from errors in the lower-frequency data is higher, and thus the probability of reconstructing good-quality data (e.g., image, video or sound) is higher. For effective and efficient error resiliency, many issues need careful study and some are addressed in this paper. We investigate our error resiliency approaches applied to wavelet compression of images.