WAVELET TRANSFORMS IN A JPEG-LIKE IMAGE CODER

The discrete wavelet transform (DWT) is incorporated into the JPEG bas eline system for image coding. The discrete cosine transform (DCT) is replaced by an association of two-channel filter banks connected hiera rchically. JPEG block-scanning and quantization schemes are adopted wh ile we use JPEG's entropy coder. The changes in scanning can be incorp orated into the transform block in such a way that the only part that needs to be changed in a JPEG framework is to replace the DCT by the D WT. Objective results and reconstructed images are presented demonstra ting that the proposed coder outperforms JPEG and approaches the perfo rmance of more sophisticated and complex wavelet coders. However, it d oes not require full-image buffering nor imposes a large complexity in crease.