I am working with dynamic images and I have encountered the following problem:

<?php
        include("image.php");
 
        $image = genimage(2000000, 20000000);
        print "it worked";
 
?>


function genimage($xsize, $ysize)
{
        $image = ImageCreate($xsize, $ysize);
        if      (!$image)
                die("cannot create image<br>\n");
 
        # painting background
        $white = ImageColorAllocate($image, 255, 255, 255);
        ImageFill($image, 1, 1, $white);
 
        return $image;
}

When I am running the script Apache will allocate a lot of memory even if memory_limit in php.ini is set to 8 megabytes of RAM. I guess that this is a bug because PHP does not seem to check for memory violation before allocating the memory needed by the pic.
Is there a way to solve the bug or at least to get around it. Maybe the problem has to do with GD (PHP cannot check before allocating). If it is this way this should be documented.

Thanks for your work,
    Hans