Lossless compression of DSA image sequence based on D/sup 2/PCM coder

A novel D/sup 2/PCM compression technique has been developed in this paper for more effective lossless compression of DSA (digital subtraction angiography) image sequences, in which the correlation between subtraction images remains meaningful. By applying the lossless DPCM coder to the subtraction image, it constitutes a two-order differential coding scheme with the time variable. This proposed method is able to sufficiently reduce the temporal-space correlation. Higher compression ratio is achieved than previous techniques. The computational time and space also prove practicable and robust in real-life applications.