Maya in Mac OS (also in Linus or Unix machines) does not accept .bmp icons for some reasons. They only accept .xpm format as I still don't know what is the difference. And even more funny thing was, the .xpm converting from .bmp was only able in Windows OS, using the software that I have gotten from somewhere. That made me way annoying so far, but I do not need to struggle to copy .bmp files from my Mac to my wife's PC, convert them to .xpm files, and copy back to Mac.
I found a software called "Contenta Converter" which is for converting various formats of images and pictures. The things that I am thanking for it are, the software has .xpm format converting, able to run in Mac OS, and it's FREE as long as you use the Basic version for the personal purpose!
You can check the software here and download the basic version for free. Easy to use.
http://www.contenta-converter.com/download2.php
