Compression board speeds medical-image display
Medical-imaging systems demand lossless data compression. To meet this requirement in digital angiography, Imagraph (Chelmsford, MA) has introduced Clarity, a JPEG compression and decompression engine for the PCI bus. In operation, baseline (lossy) or lossless JPEG operations can be performed at up to 30 frames/s on standard and nonstandard image formats.
In stand-alone or off-line mode, the board uses system memory for data source and destination. When a high-speed disk system is used, real-time frame rates can easily be achieved.
Real-time or on-line decompression and display in a video window can be accomplished with the Clarity connected to one of Imagraph`s Imascan family of frame-grabber and display cards. In image-playback mode, a compressed data stream from system memory can be decompressed and viewed at a rate from still to real time. This configuration also supports real-time capture and compression with live video in a window. In this type of configuration, data are captured and displayed on an Imascan board while being transferred to the Clarity board for compression.
The first member of the ICE Clarity family is tailored for gray-scale operation and has been applied to angiographic imaging. Future versions of the board will support RGB, YUV 8-8-8, and YUV 4-2-2 color and gray-scale data.