#39273 [NEW]: imagecopyresized() not compatable with alpha channel

From: seth at pricepages dot org Operating system: Mac 10.4 PHP version: 5.1.6 PHP Bug Type: GD related Bug description: imagecopyresized() not compatable with alpha channel Description: ------------ imagecopyresampled() should be copying the alpha channel, but it doesn't seem to be doing so. This is a palette based source image being copied to a true color image. If you use imagecopy() instead, the image copies as expected (mostly). Reproduce code: --------------- <?php $small = imagecreatefrompng('http://leopold.sage.wisc.edu/test.png'); $width = 300; $height = 300; $srcW = imagesx($small); $srcH = imagesy($small); $img = imagecreatetruecolor($width, $height); //Make a transparent canvas $trans = imagecolorresolve($img,255,255,255); imagecolortransparent($img, $trans); imagealphablending($img, false); imagefilledrectangle( $img, 0, 0, $width, $height, $trans); //This shouldn't *need* to be on, but it does imagealphablending($img, true); //One of these works, the other doesn't //imagecopy($img, $small, 0,0, 0,0, $srcW, $srcH); imagecopyresized($img, $small, 0,0, 0,0, $width, $height, $srcW, $srcH); header('Content-Type: image/png'); imagepng($img); ?> Expected result: ---------------- An enlarged, pixellated, mostly transparent, image. Actual result: -------------- A black, opaque, image. -- Edit bug report at http://bugs.php.net/?id=39273&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=39273&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=39273&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=39273&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=39273&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=39273&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=39273&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=39273&r=needscript Try newer version: http://bugs.php.net/fix.php?id=39273&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=39273&r=support Expected behavior: http://bugs.php.net/fix.php?id=39273&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=39273&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=39273&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=39273&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=39273&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=39273&r=dst IIS Stability: http://bugs.php.net/fix.php?id=39273&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=39273&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=39273&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=39273&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=39273&r=mysqlcfg