imagesavealpha Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images. Description boolimageistruecolor resourceimage imageistruecolor sets the flat to attempt to save full alpha channel information (as opposed to single-color transparency) when saving PNG images. You have to unset alphablending (imagealphaplending($im, &false;)) to use it. Alpha channel is not supported by all browsers, if you have problem with your browser, try to load your script with a alpha channel compliant browser, i.e. latest mozilla. See also imagealphablending.