#45030 [Opn]: Destination image alpah channle noise when using imagecopyresampled

ID: 45030 User updated by: lieyang at yahoo dot com Reported By: lieyang at yahoo dot com Status: Open Bug Type: GD related Operating System: x86_64 GNU/Linux Kernel 2.6.9-4 PHP Version: 5.2.6 Assigned To: pajoye New Comment: Here are my test source image (png 90x90): http://tinyurl.com/65tdtm Resized to 56x56 with noise in alpha channel: http://tinyurl.com/6yold7 Previous Comments: ------------------------------------------------------------------------ [2008-05-18 03:41:50] lieyang at yahoo dot com Please try the following with different image sizes and you will see that the alpha channel has noise. (I have two original before and after images but can not find the link to upload them as attachments) $imageSrc = imagecreatetruecolor(90, 90); imagealphablending($imageSrc, false); imagesavealpha($imageSrc, true); $color = imagecolorallocatealpha($imageSrc, 0, 0, 0, 127); imagefill($imageSrc, 0, 0, $color); $imageDst = imagecreatetruecolor(56, 56); imagealphablending($imageDst, false); imagesavealpha($imageDst, true); imagecopyresampled($imageDst,$imageSrc, 0, 0, 0, 0, 56, 56, 90, 90); header('Content-type: image/png'); imagepng($imageDst); ------------------------------------------------------------------------ [2008-05-17 23:11:41] rasmus@php.net We need a better reproducible example here, including the source image. When the source image has a perfect alpha channel, I see no noise. Try this: $imageSrc = imagecreatetruecolor(500, 500); imagealphablending($imageSrc, false); imagesavealpha($imageSrc, true); $color = imagecolorallocatealpha($imageSrc, 0, 0, 0, 127); imagefill($imageSrc, 0, 0, $color); $imageDst = imagecreatetruecolor(50, 50); imagealphablending($imageDst, false); imagesavealpha($imageDst, true); imagecopyresampled($imageDst,$imageSrc, 0, 0, 0, 0, 50, 50, 500, 500); header('Content-type: image/png'); imagepng($imageDst); ------------------------------------------------------------------------ [2008-05-17 22:52:00] pajoye@php.net In fact yes, I need the source image (what you have in $imageData). Sorry for the double posts. ------------------------------------------------------------------------ [2008-05-17 22:48:55] pajoye@php.net no need for src images :-) ------------------------------------------------------------------------ [2008-05-17 22:43:05] pajoye@php.net Please provide me the source image and the result you get. You can use http://bugs.libgd.org as well as you can add attachments to your report. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/45030 -- Edit this bug report at http://bugs.php.net/?id=45030&edit=1