Increasingly, data produced by image-processing systems are limited by storage and transmission capacities. In medical-imaging systems, especially, effective data-compression techniques are needed to overcome this problem.
Increasingly, data produced by image-processing systems are limited by storage and transmission capacities. In medical-imaging systems, especially, effective data-compression techniques are needed to overcome this problem. Today, many standards exist, including those based on run-length encoding (RLE), Joint Photographic Experts Group (JPEG), and wavelet-compression techniques. This month we take a look at some of these software packages and how they are being use to enhance medical imaging systems.
More than compression
On the Web site of Lead Technologies (Charlotte, NC), you'll find a description of the company's latest Video CODEC, a compression and decompression software filter, which integrates with any application using Video for Windows. You'll also find a range of other imaging tools including those for medical, document, and multimedia imaging.
ImageTool GmbH (Munich, Germany) designs and develops specialized image-processing solutions that can be used as stand-alone applications or that can be integrated in complex systems. On this site, there are descriptions of all the company's products including It-Reduce, a software package for still image compression. Using the package, developers can automatically select an optimal compression scheme, depending on the content and type of a given image.
Developed by Michael Schindler of Data Compression Consulting (Vienna, Austria; www.compressconsult.com), the Universal Coder uses a proprietary compression algorithm to achieve better compression than Zip and encodes fast enough to be used in real-time products. Licensed to Intelligent Compression Technologies (ICT; Falmouth, MA), the ICTs Coder is available as a Win 95/NT DLL, a demo of which can be downloaded from this site.
Freely available from the Web site of Compression Engines (The Woodlands, TX), the Compression Engine Professional for Windows 95/98/NT/ 2000 can read most still image formats and can compress them into the company's Wavelet Image File (WIF) format. Other free products that can be downloaded include an ActiveX control to allow WIFs to be viewed in Internet Explorer and other ActiveX containers and a plug-in for Explorer or Navigator that allows you to view WIFs directly from your browser.
GAF (Munich, Germany) has recently taken over the European distribution of the Multi-Resolution Seamless Image Database (MrSID) technology. The package uses a patented wavelet-based compression technology for compressing and viewing digital raster imagery and averages a 20:1 compression ratio for gray-scale images and 50:1 for color. From the GAF Web site, you can download a MrSID viewer licensed from International Land Systems (www.landsystems.com).
Combining its technology with licensed patents, Image Power (Vancouver, BC, Canada) produces image-compression products for both end-user and embedded applications. On the company's Web site, you'll find a description of the JPEG 2000 CODEC that allows developers to control the rate of compression while creating compressed images in JPEG 2000 format. Downloadable from the site, the package is claimed to be the first implementation of Part 1 of the ISO committee draft of the new standard.