PHP. Руководство по PHP. 2005
imagecolortransparent
imagecolortransparent
Description
int imagecolortransparent (resource image [, int color])imagecolortransparent() sets the transparent color in the image image to color. image is the image identifier returned by imagecreatetruecolor() and color is a color identifier returned by imagecolorallocate().
Замечание: The transparent color is a property of the image, transparency is not a property of the color. Once you have set a color to be the transparent color, any regions of the image in that color that were drawn previously will be transparent.
