raveling@vaxb.isi.edu (Paul Raveling) (02/25/89)
In article <100920057@hpcvlx.HP.COM> markc@hpcvlx.HP.COM (Mark Cook) writes: > >What's wrong the I/O file format already in use by xwd and xwud? I realize >that they don't constitute a 'standard' format, but they are already in wide >use (via the MIT distribution). ... There are a number of problems -- some are: 1. It doesn't include associated data for use by applications. For example, our map images include scale & latitude/longitude bounds as ascii text in the file header. 2. It DOES include a lot of things that are unneeded complexity for most image users. Some of the excess baggage relates to views of the image (e.g., window geometry) rather than the image itself. 3. It's not widely used. Among all the sources of images that I know of on the net, none supply images in XWD format. More popular formats are GIF, Sun rasterfiles, TIFF, and a cast of dozens more. We've learned a fair bit about requirements for simple image formats after more than a year of using our own format under X. Some of the discussion at the image processing BOF at the X Conference backed up much of what we learned. The bottom line is that none of the current file formats are entirely satisfactory; some are close, but still no cigar. I think we should open the floor for nominations for a "simple image" format and matching support software. The combination should meet the requirements of virtually all "ordinary" image display -- being able to represent images for use as background tiles, icons, & such. It need not support more sophisticated image display and image processing needs (e.g., wouldn't include data for gamma correction). Above all, the file format and the associated processing functions should be "as simple as possible, but not simpler". Before Monday's done I'll post a nomination in the form of a file format spec, and I'd encourage others to do the same. It would seem best to post to both comp.graphics and comp.windows.x (& any others?); so far most of the attention to file formats has been in comp.graphics. ---------------- Paul Raveling Raveling@isi.edu