Convert G4 to HRZ

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 HRZ file extension is associated with Slow Scan Television (SSTV), a method used by amateur radio operators to transmit still images via radio waves. HRZ files store images rendered from SSTV audio signals, typically as 256x240 pixel RGB bitmaps. These files can be viewed using software like XnViewMP or Logipole Konverter. SSTV allows for the transmission of images over high-frequency bands using single-sideband modulation (SSB). The HRZ format is not widely produced by specific programs, but several image viewers support it.