From: markg852 at hotmail dot com Operating system: Windows XP, linux PHP version: 5.1.6 PHP Bug Type: GD related Bug description: GD imagecopyresampled() bug
Description: ------------ This bug can be found when trying to make a thumbnail from a url (example: http://promote.opera.com/logos/Opera5_t.png) the png isn`t even transperant anymore unless these 3 lines of code are also added: $background = imagecolorallocate($thumb, 0, 0, 0); ImageColorTransparent($thumb, $background); // make the new temp image all transparent imagealphablending($thumb, false); // turn off the alpha blending to keep the alpha channel i tried everything i could thing of but the quality stays different.. What the code below does is the following: 1. It downloaded the opera logo png image and makes a thumbnail of the URL!! 2. (after hitting F5) the code will make another thumbnail from the downloaded full scale image. 3. (after hitting F5 2nd time) the code will show both thumbnails and look at the quality difference!! and without the 3 lines posted above the "ugly" image has a black background!! Reproduce code: --------------- <?php // Error Reporting error_reporting(E_ALL); // File and new size if (file_exists('thumb_van_url.png') AND file_exists('thumb_van_path.png')) { echo '<img src="./thumb_van_url.png"></img>'; echo "Thumbnail made from URL"; echo '<img src="./thumb_van_path.png"></img>'; echo "This one is made from a PATH"; exit; } elseif (file_exists('./Opera5_t.png')) { $filename = 'Opera5_t.png'; $mid = 'van_path'; } else { $filename = 'http://promote.opera.com/logos/Opera5_t.png'; $mid = 'van_url'; imagepng(imagecreatefrompng('http://promote.opera.com/logos/Opera5_t.png'), 'Opera5_t.png'); } $percent = 0.1; // Get new sizes list($width, $height) = getimagesize($filename); $newwidth = $width * $percent; $newheight = $height * $percent; // Load $thumb = imagecreatetruecolor($newwidth, $newheight); $source = imagecreatefrompng($filename); $background = imagecolorallocate($thumb, 0, 0, 0); ImageColorTransparent($thumb, $background); // make the new temp image all transparent imagealphablending($thumb, false); // turn off the alpha blending to keep the alpha channel // Resize imagecopyresampled($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); // Output imagepng($thumb, 'thumb_' . $mid . '.png'); echo '<img src="./thumb_' . $mid . '.png"></img>'; // Content type // header('Content-type: image/png'); // readfile('thumb_' . $mid . '.png'); ?> Expected result: ---------------- http://img393.imageshack.us/img393/2796/uitkomstvc4.png -- Edit bug report at http://bugs.php.net/?id=38764&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=38764&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=38764&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=38764&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=38764&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=38764&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=38764&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=38764&r=needscript Try newer version: http://bugs.php.net/fix.php?id=38764&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=38764&r=support Expected behavior: http://bugs.php.net/fix.php?id=38764&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=38764&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=38764&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=38764&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=38764&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=38764&r=dst IIS Stability: http://bugs.php.net/fix.php?id=38764&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=38764&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=38764&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=38764&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=38764&r=mysqlcfg
