Convert RAD to PGM

The RAD file extension, associated with the Radiance software suite, stands for Radiance Scene Description. It is used to describe materials and geometry for lighting simulations and rendering programs. Developed by Greg Ward at Lawrence Berkeley National Laboratory, Radiance employs ray tracing and an octree data structure for accurate lighting calculations. RAD files are ASCII text files that must be compiled into an octree before rendering.

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.