Wavelet-based lossless compression of coronary angiographic images

The final diagnosis in coronary angiography has to be performed on a targe set of original images, Therefore, lossless compression schemes play a key role in medical database management and telediagnosis applications, This pa per proposes a wavelet-based compression scheme that is able to operate in the lossless mode. The quantization module implements a new way of coding o f the wavelet coefficients that is more effective than the classical zerotr ee coding, The experimental results obtained on a set of 20 angiograms show that the algorithm outperforms the embedded zerotree coder, combined with the integer wavelet transform, by 0.38 bpp, the set partitioning coder by 0 .21 bpp, and the lossless JPEG coder by 0.71 bpp, The scheme is a good cand idate for radiological applications such as teleradiology and picture archi ving and communications systems (PACS's).