Convert SGI to PNM

The SGI file extension stands for Silicon Graphics Image, a raster graphics file format developed by Silicon Graphics Inc. primarily for their IRIS workstations. This format, originating in the late 1980s, supports uncompressed and RLE-compressed data with up to 48-bit color (16 bits per channel for RGB) and an alpha channel. SGI files are widely utilized in 3D graphics, visualization, and high-end imaging due to their ability to store high-quality images and intricate details, making them an essential asset in professional graphics and animation industries.

The PNM (Portable Anymap) file extension, developed by Jef Poskanzer in the 1980s, stands for Portable Any Map. It is an uncompressed raster graphics format designed for portable image storage and exchange, encompassing three sub-formats: PBM (Portable Bitmap), PGM (Portable Graymap), and PPM (Portable Pixmap). PNM files store image data in plain text or binary format, ensuring easy usage across different platforms and applications. This format is widely supported by various image editing software and is valued for its simplicity and lossless compression.