(PHP 4 >= 4.0.6)imagecolorresolvealpha -- Get the index of the specified color + alpha or its closest possible alternative
Descriptionint imagecolorresolvealpha ( resource image, int red, int green, int blue, int alpha)
This function is guaranteed to return a color index for a requested color, either the exact color or the closest possible alternative.
See also imagecolorclosestalpha().
Note: This function was added in PHP 4.0.6 and requires GD 2.0.1