ID: 33914 User updated by: me at thomaskeller dot biz Reported By: me at thomaskeller dot biz Status: Bogus Bug Type: GD related Operating System: Linux 2.4 shared hosting PHP Version: 4.3.11 Assigned To: pajoye New Comment:
> Again it's not a bug. > You have to set the transparent color correctly > in the destination image. So what means "correctly" here? I've tried several dozens of combination to get the desired result but failed with each. I copied palettes over, tried to copy into a 32bit target image while later shrinking it back via imagetruecolortopalette, and more. I'll promise I'll shut up if you just give me a few lines of CORRECT code. The docs don't help me on my problem. I've also noticed that a list($r, $g, $b) = imagecolorsforindex(...) doesn't work as suspected, because all three variables are unset. This is my current code: <?php $im_source = imagecreatefromgif($somefile); $im_target = imagecreate($width, $height); $idx = imagecolortransparent($im_source); $rgba = imagecolorsforindex($im_source, $idx); imagecopyresampled($im_target,$im_source, 0, 0, 0, 0, $new_width, $new_height, $orig_width, $orig_height); $transColor = imagecolorallocate($im_target, $rgba['red'], $rgba['green'], $rgba['blue']); imagecolortransparent($im_target, $transColor); header("Content-type: image/gif"); imagegif($im_target); exit; ?> imagecolortransparent on $im_target afterwards returns the index for the transparent color (white), but still the background of the image has another color (rgb 128,64,88). If I set this color to be transparent, nothing happens (its still there). Previous Comments: ------------------------------------------------------------------------ [2005-07-29 18:19:57] [EMAIL PROTECTED] Again it's not a bug. You have to set the transparent color correctly in the destination image. --Pierre ------------------------------------------------------------------------ [2005-07-29 18:12:15] [EMAIL PROTECTED] RTFM: http://www.php.net/imagecolortransparent ------------------------------------------------------------------------ [2005-07-29 17:36:48] me at thomaskeller dot biz I have already provided a sample script, which is available on http://thomaskeller.biz/work/php/PHP_GIF/image.php, the source for this file is http://thomaskeller.biz/work/php/PHP_GIF/image.phps [0]. The test image which fails to be scaled is http://thomaskeller.biz/work/php/PHP_GIF/rose.gif As you can see here [0] the problematic code seems to be (shortened): <?php $idx = imagecolortransparent($im_src); if ($idx > -1) // transparent color found? { list($r, $g, $b) = imagecolorsforindex($im_src,$idx); $transColor = imagecolorexact($im_target, $r, $g, $b); imagecolortransparent($im_target, $transColor); } ?> where I try to receive the index of the transparent color of the original image, then find the rgb value of this color and finally create a new color on the target image using the rgb value and set it as transparent color. ------------------------------------------------------------------------ [2005-07-29 17:19:21] [EMAIL PROTECTED] Provide a sample (and little) script and the images causing your problem may help. For what you said, the "random" color may in fact be the background. You have to set the transparent color yourself to the dest image. Short version, it's not a bug as far as I can tell now. I keep this bug to bogus, if you have a reproducable script with one image, turn it back to open. ------------------------------------------------------------------------ [2005-07-29 02:37:12] me at thomaskeller dot biz Description: ------------ Following use case: Uploaded images should be shrinked to a certain size according to our guidelines. Works with jpeg/ png (not palette based) images without a problem, problems arise when used palette based (8bit) images. Resizing via imagecopyresampled/ imagecopyresize works only for images WITHOUT a transparency color set properly. If a transparency color is set in the image, the value of this color is just ignored and a random background color is applied to the "transparent" area. It makes no difference if the image is outputted as gif or 8bit png. If imagecopyresampled/imagecopyresized is called with the same width/height for the source and the target image, the transparency keeps intact. Reproduce code: --------------- I've setuped a few things on a test server: PHPInfo: http://thomaskeller.biz/work/php/PHP_GIF/info.php Testfile: http://thomaskeller.biz/work/php/PHP_GIF/image.php Testfile (Source): http://thomaskeller.biz/work/php/PHP_GIF/image.phps image.php loads http://thomaskeller.biz/work/php/PHP_GIF/rose.gif by default, but you can load an own gif file via URL like image.php?filename=http://your.server.com/file.gif The loaded image is per default resized to its double width/ height. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=33914&edit=1