DICOM committee votes to keep compression group alive

DICOM committee votes to keep compression group alive

Digital mammography group also formed

The DICOM standards committee voted at its August meeting to keep active its working group charged with developing standards to cover new lossy compression algorithms. There had been some industry speculation that the committee might place Working Group 4 on inactive status following a vote earlier this year not to proceed with the group's work (PNN 8/97).

Instead, Working Group 4 will now serve as the formal liaison between the DICOM standards committee and the JPEG 2000 committee of the Joint Photographic Experts Group, which is examining data compression for several applications, including medical imaging. The working group will also evaluate a request from the ultrasound working group to incorporate the MPEG 2 compression standard for dynamic images into DICOM.

Working Group 4 has been trying to develop a standard for lossy compression techniques, like wavelet compression, to enable lossy algorithms from different vendors to work together. Vendors are developing wavelet techniques due to dissatisfaction with the shortcomings of JPEG.

The move by the DICOM standards committee, while falling short of placing the group on inactive status, will still delay the addition of new lossy compression standards until the release of JPEG 2000, which is expected in November 2000. The committee's move is also evidence of its belief that the addition of new lossy standards would be best served through JPEG 2000, which will have the support of users in the broader consumer PC market.

The next meeting of Working Group 4 will be convened by Tamim Hamid of image archiving developer QuVis and will give members the opportunity to select a new chairman, said Steven Horii, co-director of the DICOM standards committee. For information on joining Working Group 4, contact Hamid at thamid@quvis.com.

Meanwhile, a group of researchers at the University of California, San Francisco, in conjunction with film and PACS developer Agfa, are proceeding with the development of their own lossy compression technique, to include wavelet algorithms, which they hope will become a de facto standard in the absence of an official DICOM 3.0 policy. Other institutions in the group include the University of Pennsylvania in Philadelphia, the University of Pittsburgh, and Massachusetts General Hospital.

In other DICOM news, the committee has launched a digital mammography working group. The group's responsibility will be to define the requirements in DICOM for storage of digital mammography images and reports. David Clunie of GE Medical Systems (david.clunie@med.ge.com) will convene the first formal meeting of the group and will serve as chairman pro tem until a chairperson is elected.

The working group is expected to work closely with the digital radiography working group (WG 2), structured reporting working group (WG 8), and the display working group (WG 11). The first meeting of the digital mammography working group has yet to be determined.