Descriptionint imagecolorexactalpha ( resource image, int red, int green, int blue, int alpha)
Returns the index of the specified color+alpha in the palette of the image.
If the color does not exist in the image's palette, -1 is returned.
See also imagecolorclosestalpha().
Note: This function was added in PHP 4.0.6 and requires GD 2.0.1 or later