Real-time distortionless high-factor compression scheme

To provide a low-cost solution for the cardiac acquisition, General Electric CGR has designed a distortionless compressor/decompressor board that is part of its digital subtraction angiography equipment. During acquisition, the real-time compressor transforms the input images into a lower quantity of coded information through a DPCM coder and a variable-length Huffman code. The process is fully reversible since, during review, the real-time decompressor exactly recovers the acquired images from the stored compressed data. Test results on large amounts of raw images demonstrate that two image disks are sufficient to store at least 15,000 cardiace images (5122 X 8 bits). The system works equally well on 5122 or 1,0242 formats and 256 or 1,024 gray levels