How to read a .pgm image file in a 2D double array

Question

The question is quite simple: How to read a .pgm image file into a 2D double array in C. I do not have a .pgm buffer in memory. I would like to read it from the disk into memory.

Would really appreciate if I could get a code snippet. Thank You.

Answer 1

You probably won't get someone writing you all the code, but here are some useful links that might point you in the right direction:

• pgm.c
• pgm.h
• PGM Format Specification
• http://www.cplusplus.com/forum/general/2393/

Answer 2

If its saved as ASCII you could just read it with the "normal" file reading methods of C. You can of course use the netpbm library (linux only?), which gives you functions to handle a pgm file.