Create a transparent png file using PHP

Question

Currently I would like to create a transparent png with the lowest quality .

The code:

Answer 1

To 1) imagecreatefrompng('test.png') tries to open the file test.png which then can be edited with GD functions.

To 2) To enable saving of the alpha channel imagesavealpha($img, true); is used. The following code creates a 200x200px sized transparent image by enabling alpha saving and filling it with transparency.