Convert HRZ to PGM

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.

The Portable Graymap (PGM) file extension, originating in the late 1980s as part of the Netpbm project, stands for "Portable Gray Map". It serves as a simple, versatile format for grayscale images, enabling easy reading and writing by various programs. Due to its straightforward structure and plain text encoding, it's often used in academic and research settings where ease of parsing and accessibility are crucial. PGM files store grayscale images in a compact, efficient manner, making them an essential tool for image processing tasks.