Convert PAM to G3

The PAM (Portable Arbitrary Map) file extension is a versatile bitmap format used primarily in UNIX-based systems. It extends the Portable Any Map (PNM) format, supporting 2-dimensional image data storage in a binary format with an ASCII header. Introduced to enhance flexibility and interoperability in image processing, PAM files are utilized for various graphical applications, offering a standardized method for handling diverse image types. This format's history traces back to the need for a more adaptable and comprehensive bitmap solution within the PNM family.

The G3 file extension refers to the CCITT Group 3 Fax Image, a standardized format developed by the Consultative Committee for International Telegraphy and Telephony (CCITT), now known as ITU-T. This format was created to efficiently compress black-and-white fax documents for transmission over telephone lines. It employs a method called Modified Huffman Coding for data compression, enabling reduced transmission time and bandwidth usage. G3 was widely adopted in the 1980s and 1990s as the primary standard for fax transmissions, ensuring compatibility across different fax machines and systems.