Here is the calling unit:
implicit none
integer (4) file_size, hpix, vpix
integer (2) k, l, m
character *100 fisi
character *54 header
character *1, allocatable :: r(:), g(:), b(:)
open(1, file = fisi)
call read_bmp_header(int2(1), file_size, hpix, vpix)