Convert pcx to pgm

What is the difference between .pcx and .pgm?

Description: PCX, standing for Paintbrush Bitmap Image, is a raster image format developed by ZSoft Corporation for their PC Paintbrush graphics program. Initially released in the 1980s, PCX was one of the first widely used bitmap image formats on IBM PC compatible computers. The format supports 1-bit monochrome, 4-bit palette, 8-bit palette, and 24-bit true color images, allowing for a wide range of colors and shades.; 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.