bsy's face file format

bsy is now at UCSD, and this page is no longer being maintained here.
The face file format is used by the face program for very fast, lowest common denominator displays. The images are pre-dithered black-and-white bitmaps, making it easy to display even on the slowest X capable machines.

If you are in CMU CS, running the face program will be much faster than accessing faces through Mosaic. To try it out, go to a shell and type

% /usr/misc/.X11-others/bin/face bsy
The face program will pop up a new window containing an image of my face. (You can use your mouse to cut-and-paste the above text.)

Translating from the face format to X bitmaps for use by mosaic is very fast. Unfortunately, mosaic always interprets X bitmaps according to the current Foreground and Background pixel resources. While this is great for icons, if your preferences are for white-on-black (or other color combination) rather than the default black-on-white, the image that mosaic displays for you would be a negative one. GIF formatted data, on the other hand, are displayed ``properly''. Thus, the http_face server currently translates the face image data to GIF format, making the entire process slower.

If you use white-on-black, click here to see what I mean. If you use Mosaic, the images will be inverted unless you set the global XMosaic*reverseInlinedBitmapColors resource correctly.

Future extensions include adding ``sections'' to the face format to provide optional (to the image-provider), un-dithered GIF or JPEG style data so that the client software may elect to perform the image processing required to optimize the image for the user's display. This sort of functionality would not be directly accessible from mosaic unless mosaic incorporates better customization features or explicitly different hyperlinks are provided for access the same image with different display qualities.

But first, thesis work....

CMU Censorship | SCS home | refs | other folks | SCS News | WWW News

bsy picture /, last updated 4 April 1996.

Join the Blue Ribbon Anti-Censorship Campaign!