im_writeline - writes a line of data in the image descriptor
int im_writeline(ypos, image, buffer)
im_writeline(3) writes the ypos line of an image held in buffer to
either the output buffer image (previously set by im_setbuf(3)) or to
an output file (previously set by im_openput(3)). The function
provides uniform treatment of output irrespectively whether it is a
file or a buffer image.
You should be careful that the buffer does indeed contain enough data
for a complete line of pels --- see lsize(3).
Any evaluation callbacks which have been added to image are triggered
--- see im_generate(3) and im_add_eval_callback(3).
This function changed in VIPS6: programs written previously must be
modified by removing the last argument of the old im_writeline(3).
The function returns 0 on success and -1 on error.
im_setbuf(3), im_openout(3), im_add_eval_callback(3).
N. Dessipris 23/04/1991
22 April 1991