Design of wavelet-based image codec in memory-constrained environment
This work presents a high-performance wavelet transform based image coder that is designed for image compression in a system with limited resources. In this image coder, the dual-sliding wavelet transform (DSWT) is first applied to the image data to generate wavelet coefficients in fixed-size blocks. Here, a block consists of wavelet coefficients only from a single subband. Then, the resulting coefficient blocks are directly coded with the low-complexity binary description (LCBiD) coefficient coding algorithm. No parent-child relationship is exploited in the coding process. There is no intermediate buffering needed between DSWT and LCBiD. The compressed bit stream generated by the proposed coder is both SNR and resolution scalable, as well as highly resilient to transmission errors. Both DSWT and LCBiD process the data in blocks whose size is independent of the size of the input image. This gives more flexibility in its implementation. The codec has a very good coding performance even the size of a coefficient block is as small as (16,16).