Abstract: A new algorithm with lossless regions of interest is present based on the Integer Wavelet Transform(IWT) and SPIHT scheme. It utilizes the good space-frequency local characteristic of the wavelet transform, and lifts the wavelet coefficients of regions of interest in an image, and by this means, these wavelet coefficients will be separated from wavelet coefficients in the background. An image can be encoded with an arbitrarily shaped ROI by this method, and an arbitrarily shaped ROI can be decoded without transmitting any information about the shape of ROI. Experimental results show that the algorithm can losslessly preserve regions of interest and obtain a higher compression ratio of the whole image.

Key words: regions of interest, integer wavelet transform, SPIHT scheme, still image compression