PHP: How to make a green area (background) in an image transparent?

Question

I\'m new here on Stackoverflow.

I would very much like figure out if it\'s possible to make a specific color of an image transparent using a PHP script. And if it is, ho

Answer 1

imagecolortransparent() will help you:

...
$yourColor = imagecolorallocate($im, 0, 0, 0);
imagecolortransparent($im, $yourColor);
...

Answer 2

• demo : http://so.devilmaycode.it/php-how-to-make-a-green-area-background-in-an-image-transparent

first of all the image should be png cause jpeg don't support transparency then the code is like this:

<?php
   $image = 'test.png';
   $im = imagecreatefrompng($image); 
   //if you exactly know the RGB color indexes
   //$rgb = imagecolorexact($im, 0, 0, 0);
   //or keep the rgb color by position so at top 0 left 0
   $rgb = imagecolorat($im, 0, 0);
   imagecolortransparent($im, $rgb);
   header("Content-type: image/png");
   //display the image directly
   imagepng($im);
   // or save it
   // imagepng($im, 'test-to-transparent.png');
   imagedestroy($im); 
?>