Question

How it’s possible to get the transparency value of a pixel on an image?

‘imagecolorat’ picks only the index of the color of the pixel at the specified location in the image. With that index I can get the RGB values but not the transparent one.

Hope you understand, and thank you in advance.

Answer 1

As far as I know, the transparency value is returned by the function imagecolorat. Could you try:

$color        = imagecolorat($image, $x, $y);
$transparency = ($color >> 24) & 0x7F;

The transparency is a integer between 0 and 127 so we need to mask the first 8 bits of the 32bit color integer.