The SGI™ Image File format is a bitmap file type created by Silicon Graphics ® . SGI Image File support in 3ds Max lets you load and save files in both 8- and 16-bit color depth, with alpha channels, and RLE Compression.
SGI Image Files can have these filename extensions: SGI, RGB, RGBA, INT, INTA, or BW.
Clicking Render or Setup in the Render Output File dialog displays the RGB Image File Format dialog.