Convert CAL to HRZ

The CAL file extension, known as CALS (Continuous Acquisition and Life-cycle Support) Type 1 Image, is a 1-bit black-and-white raster image format developed by the U.S. Department of Defense in the mid-1980s to standardize graphics data interchange for military documentation. It is primarily used for storing and sharing monochrome images while retaining orientation metadata. The format supports both uncompressed and compressed (using CCITT Group 4 compression) images.

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.