Other Image Commands

In addition to automatic ``conversion'' of media types, once a GIF is displayed/selected in the media browser, the ``make background transparent'' command may be invoked - this allows the ``background'' color of the GIF to be displayed using the background color (or tiled bitmap background) of the browser instead of the ``background'' color. This gives the effect of having the image pop up out of the browser's display.

In the future, it probably makes sense to allow a user-definable list of commands to be defined for the GIF image browser's popup menu. Default commands could include simple PBM-PLUS pipelines to perform certain useful image manipulations automatically, e.g. ``reduce image by 10%'' ``increase image by 10%'', ``make 100*100 thumbnail'', ``make 200*200 thumbnail'', ``make 300*300 thumbnail'', etc.

For example, the following ``entry'' in the extensible GIF operators file is what ``make 100*100 thumbnail'' would look like:

(``make 100*100 thumbnail''
 ``giftoppm ~A | pnmscale -xysize 100 100 | ppmdither -red 3 -green 4 -blue 3 |\
   ppmtogif > ~A'')

Where the first ``~A'' represents the GIF input file name, and the second ``~A'' represents the output GIF file. The convention used is that of the Common Lisp format command, since WINTERP is used to create the user-customizable menus.