Not all of these tools are available on all machines. The steps of converting the PPM file to PGM and PGM to PBM do this. Image manipulations are possible, too. This command smoothes the image in a GIF file and writes it to a new file.
Many more combinations are possible.
These, in turn, will list the various tools available under their classification. It can display and perform rudimentary manipulations on GIF, JPEG, PBM, Sun Raster, and other formats. A window will open showing information about the package. Move the mouse pointer to the window and click the right button. XV is pretty self-explanitory from this point on, but you may want to read the manual pages for it.