Convert PGM to SR

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.

The Sun Raster (SR) file extension, is a raster graphics file format developed by Sun Microsystems for use on their SunOS operating system. This format, which stores black-and-white, grayscale, and color bitmapped data, was widely used in UNIX-based systems and supported by various imaging applications. The Sun Raster format includes a header, an optional color map, and the bitmapped image data. Although it does not support transparency, it remains a simple and widely distributed bitmap format.