PHP/PNG Alpha Blending Problem

Chardee MacDennis · 20-11-2008 06:58PM #1

Hey having some trouble trying to maintain transparency on a png when i create a thumbnail from it, anyone any experience with this? any help would be great, here's what i am currently doing:

    $fileName= "../js/ajaxupload/tees/".$fileName;
    
    list($width, $height) = getimagesize($fileName);
    
    $newwidth = 257;
    $newheight = 197;
    
    $thumb = imagecreatetruecolor($newwidth, $newheight);
    imagealphablending($thumb, true);
    $source = imagecreatefrompng($fileName);
    imagealphablending($source, true);
    
    imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
    
    imagesavealpha($thumb, true);
    imagepng($thumb,$newFilename);

Chardee MacDennis · 22-11-2008 12:18AM

no one?

Webmonkey · 22-11-2008 12:43AM

I'm guessing you'll have to place the

[php] imagesavealpha($thumb, true);[/php]

Before you do the resizing:
[php]imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);[/php]

I'm half asleep now but worth a shot anyways.

Chardee MacDennis · 24-11-2008 01:01AM

got it with this:

$thumb = imagecreatetruecolor($newwidth, $newheight);
	imagealphablending($thumb, false);
	imagesavealpha($thumb, true);  
	
	$source = imagecreatefrompng($fileName);
	imagealphablending($source, true);
	
	imagecopyresampled($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
	
	imagepng($thumb,$newFilename);

thanks for the help!

PHP/PNG Alpha Blending Problem

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