PHP GD transparency doesn't work with iPhone - php

Question

I am using code to create an image with PHP GD that needs a fully transparent background. When I create it, it displays fine in a browser, but bad in my iPhone app. I don't know why, but in my iPhone it displays all transparency with black. This seems to be a GD problem because when I loaded my GD image into a web editor and reexported it, it displayed fine in my iPhone app. Is there a special way I should export the png image from GD or something or is this some sort of bug? Here is the code:
$filename = "./me.jpg";
$image_s = imagecreatefromjpeg($filename);
list($current_width, $current_height) = getimagesize($filename);
$left = isset($_GET['pl']) ? abs($_GET['pl']) : 0;
$top = isset($_GET['pt']) ? abs($_GET['pt']) : 0;
$width = isset($_GET['cs']) ? abs($_GET['cs']) : 65;
$height = isset($_GET['cs']) ? abs($_GET['cs']) : 65;
$canvas = imagecreatetruecolor($width, $height);
$current_image = imagecreatefromjpeg($filename);
imagecopy($canvas, $current_image, 0, 0, $left, $top, $current_width, $current_height);
$newwidth = 65;
$newheight = 65;
$image = imagecreatetruecolor($newwidth, $newheight);
imagealphablending($image, true);
imagecopyresampled($image, $canvas, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
$mask = imagecreatetruecolor($newwidth, $newheight);
$transparent = imagecolorallocate($mask, 255, 255, 255);
imagecolortransparent($mask, $transparent);
imagefilledellipse($mask, $newwidth / 2, $newheight / 2, $newwidth, $newheight, $transparent);
$red = imagecolorallocate($mask, 0, 0, 0);
imagecopymerge($image, $mask, 0, 0, 0, 0, $newwidth + 10, $newheight + 10, 100);
imagecolortransparent($image, $red);
imagefill($image,0,0, $red);
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
imagedestroy($mask);

Answer 1

Have you tried using imagesavealpha instead of imagesettransparency? Set alpha blending to false and then use imagesavealpha to true. Finally you'll call the imagecolorallocatealpha function to get your transparent/alpha color instead of imagesettransparency:
imagealphablending($image, false);
imagesavealpha($image, true);
$transparent = imagecolorallocatealpha($image, 255, 255, 255, 127);
imagefilledellipse($mask, $newwidth / 2, $newheight / 2, $newwidth, $newheight, $transparent);
etc...