thanks guys for reply
i tested: file_for_screen (STRING* filename,var number);

it solves my squeezing problem partially.
but since i want search objects in the screenshots (track objects for a simulation) i need to access the pixel of the screenshot in realtime. therefor i dont want to save the picture first then load and analyse. i want acess them directly so i use the :
bmap_for_screen (screen_shot_map, 0, 1);
function.

and for acessing the pixel:

int dx=700;
int dy=480;
for(i1 = 0; i1 < dx; i1++)
{
for(j1 = 0; j1 < dy; j1++)
{

pixel_1 = pixel_for_bmap(screen_shot_map,i1,j1);
pixel=pixel_1;
bmp_to_send[i1][j1][0]=pixel;
}
}


but its output seems to be compressed in x-achsis.

any ideas?
thanks in advance for any sugestion