Fortran / reading a header of a binary file and write into it

[mredjlali]

Hi,
Does anyone know how to read h and v stored in byte 19 and 20 for h and 23 and 24 for v in a header of a 24-bit colour BMP file. Header has 54 bytes and overall size is 3hv+54.
Also how can I write some words into a binary file for example writing "fortran" into the withe box of at the right upper corner of 600*300 bitmap image without chnging the header? My system support fort77.
Thanks

 

[xwb]

The problem is actually how you open the file. Different versions of f77 behave differently. With g77, the following will work

open (unit, file, status='old', access = 'direct', form = 'unformatted', recl = 1)

There is a sample program in

http://www.forceproject.hpg.ig.com.br

which writes bmp files. The sample does 2, 4 and 8 bit colour: not 24 as you requested but basically it is just playing about with the header definition to get it to work. Also note that the bitmap is stored upside down.

 

[mredjlali]

Thank you so much.