This program is part of Netpbm.
sbigtopgm reads an image file in the native format used by the Santa Barbara Instrument Group (SBIG) astronomical CCD cameras, and produces a PGM image as output. Additional information on SBIG cameras and documentation of the file format is available at the Web site, http://www.sbig.com/.
sbigtopgm recognizes some variation on the documented SBIG Type 3 format. It allows any capitalization in the header. It ignores all whitespace in the header except newlines. So a header line can end in newline, CRLF, or the bizarre LF-CR actually required by the spec.