Convert JBG to PGM

The JBG file extension stands for Joint Bi-level Image Group, a format developed for efficient lossless compression of binary images, primarily used in fax transmissions. Introduced by the Joint Bi-level Image Experts Group, JBG files store 1-bit raster images and offer superior compression compared to older standards like CCITT Group 3 and 4. Although initially popular for fax machines, the format has largely been superseded by JBIG2, which provides even better compression.

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.