The SGI file extension stands for “Silicon Graphics Image” file. It is an image that was saved in the native graphics format that was used on the Silicon Graphics workstations. It supports Run-Lengh encoding ( RLE) compression that reduces the file size and can store 8 to 32 bits per pixel. This file format is very similar to RGB.
Mime type: image/sgi, image/x-sgi, image/x-sgi-rgba