Hi!

Are you sure you are using only 16 colours in you picture? Just use Gimp to reduce colours before changing the format and then just:
Code:
# bmptoppm logo.bmp > logo.ppm
bmptoppm: Windows BMP, 640x409x4
bmptoppm: WRITING PPM IMAGE
# ppmtolss16 < logo.ppm > logo.16
261760 pixels, 97307 bytes, (25.65% compression)
Of cause you can use other format too and not only bmp format.

To be honest also I have now some probem with Debian's splash.rle logo (I want to use it little modified). I can change it to ppm picture similary but makin it back after making modifications changes my white text in boot line to light red. I know that it is colour nunber 7 which is used as a text colour but how do I know wchich colour is 7th colour?

-tapsa-