Recovery of damaged code blocks in LL sub-band of JPEG 2000 images

It is well known that images of natural scenes have predominantly low frequency components. Wavelet transform (WT) which is used in JPEG 2000, concentrates the low frequency of the transformed image in LL sub-band. Hence, transmission error in LL sub-band of JPEG 2000 coded image affects the quality of the perceived image drastically. Another important aspect of JPEG 2000 standard is employing large code-blocks (normally 32times32 or larger) to provide sufficient compression efficiency. Error concealment (EC) in so large areas is a challenging problem. Filling the lost bits with zero (ZF) is the only well known EC method for large areas. In this paper the segmentation and conditional replacement (SCR) EC method is introduced for EC of LL sub-band. This method is based on the segmentation and replacement (SR) EC method and outperforms the ZF method at large areas for any number of lost bit planes in LL sub-band