Convert G4 to SIXEL

The G4 file extension, standing for CCITT Group 4 Fax Image, is a specialized format used primarily for storing black-and-white facsimile (fax) images. Its origins trace back to the Consultative Committee for International Telegraphy and Telephony (CCITT), now known as the ITU-T, which developed the Group 4 standard in the 1980s to improve fax transmission efficiency over digital networks. This format employs a high compression ratio to reduce file size while maintaining image quality, making it ideal for archiving documents and transmitting faxes in professional and business environments.

The SIXEL, or "six pixels", is a bitmap graphics format created by Digital Equipment Corporation (DEC) for their terminals and printers. Initially designed for DEC dot matrix printers like the LA50, it enabled the efficient transfer of bitmap graphics using a series of ASCII characters. Each character represents a 6-pixel high row, making it suitable for 7-bit serial communication. This format was later adapted for modern terminal emulators, extending its utility beyond its original scope.