Convert tcr to pgm

What is the difference between .tcr and .pgm?

Description: The TCR file format is associated with eBook files specifically used by Psion Series 3 devices. Psion Series 3, a range of personal digital assistants (PDAs) developed in the early 1990s, utilized these files to store and display electronic books (eBooks). TCR files are designed to be compact to suit the limited storage capacities of early PDAs. They contain the text of the eBook, and possibly basic formatting, optimized for the low-resolution screens of the Psion device.; A PGM file is a grayscale image file saved in the portable gray map (PGM) format and encoded with one or two bytes (8 or 16 bits) per pixel. It contains header information and a grid of numbers that represent different shades of gray from black (0) to white (up to 65,536). PGM files are typically stored in ASCII text format, but also have a binary representation.