Convert SGI to PGM

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 Portable Graymap (PGM) file extension, originating in the late 1980s as part of the Netpbm project, stands for "Portable Gray Map". It serves as a simple, versatile format for grayscale images, enabling easy reading and writing by various programs. Due to its straightforward structure and plain text encoding, it's often used in academic and research settings where ease of parsing and accessibility are crucial. PGM files store grayscale images in a compact, efficient manner, making them an essential tool for image processing tasks.