Convert HDR to PGM

HDR stands for High Dynamic Range, and in the context of Radiance, it refers to a file format used for storing high-quality images. The Radiance HDR format was developed as part of the Radiance rendering system, which originated in the late 1980s at the Lawrence Berkeley National Laboratory. Its primary use is in the field of computer graphics, where it captures a wider range of luminance levels compared to standard formats, enabling more realistic lighting effects. This format is particularly beneficial for tasks requiring precise light measurements and accurate visualizations, making it indispensable for professionals in fields such as architectural visualization and visual effects.

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.