Convert JNX to G3

The JNX file extension stands for "BirdsEye JNX Raster Map" and is used by Garmin devices like the Alpha 100 and Montana 650 for navigating terrain. It contains a large raster map divided into small tiles for optimized rendering and includes an encrypted unit ID for the specific Garmin device. JNX files are part of the BirdsEye subscription service, allowing fast map rendering and supporting up to 5000 tiles per level. However, they are device-specific and cannot be created from other raster maps.

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.