Convert CALS to G3

The CALS (Continuous Acquisition and Life-cycle Support) Type 1 Image file format, developed by the United States Department of Defense in the mid-1980s, is a standard for storing raster (bit-mapped) image data, typically black-and-white. It ensures efficient data interchange and retention of orientation metadata. The format supports both uncompressed and compressed (using CCITT Group 4 compression) images. This standard was part of the broader CALS initiative aimed at improving electronic publishing and data management within the federal government.

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.