ID: 48123 Updated by: paj...@php.net Reported By: vincent dot k dot hughitt at nasa dot gov -Status: Assigned +Status: Bogus Bug Type: GD related Operating System: * PHP Version: 5.2.6-3 Assigned To: pajoye New Comment:
hi, There is no bug, the difference is actually a bug fix in how GD managed PNG Grayscale images. When the grayscale image has an alpha component (PNG_COLOR_TYPE_GRAY_ALPHA), a truecolor image is created. If you use a real grayscale only image the resulting image will still be a palette image. For example: http://pierre.libgd.org/48123_eit_real_grayscale.png is a grayscale only image and works as you expect. It is not a bug, however next version of GD will support grayscale images as internal formats, that will greatly ease this kind of transformation. Previous Comments: ------------------------------------------------------------------------ [2009-04-30 19:37:17] vincent dot k dot hughitt at nasa dot gov Okay, got same result on Ubuntu 9.04 using compiled PHP + Bundled GD: PHP 5.2.6-3ubuntu4.1, GD bundled (2.0.34 compatible) ------------------------------------------------------------------------ [2009-04-30 19:12:37] j...@php.net Verified with latest CVS, using bundled GD library. ------------------------------------------------------------------------ [2009-04-30 18:11:51] vincent dot k dot hughitt at nasa dot gov Hi Pajoye, Thanks for the feedback. I did not know that about Ubuntu/Fedora's packaged versions of GD. I will try downloading and compiling PHP from source and see if I run into the same issues, and post my results here. If you start with the images: http://launchpadlibrarian.net/26034594/eit_grayscale.png http://launchpadlibrarian.net/26034597/ctable_eit304.png The expected output of the script is: http://launchpadlibrarian.net/26034598/eit_final_ubuntu810.jpg which is a COLOR image. The problem is that using newer version of PHP, the result is a GRAYSCALE image. ------------------------------------------------------------------------ [2009-04-30 17:33:11] paj...@php.net and what do you expect as "correct" result? for this script. And please not that both Debian and Ubuntu do not use the bundled GD as it is recommended and the GD version they use is in a poor state (ubuntu being less worst). Please try the same using a normal php too, compiling it with the bundled GD. ------------------------------------------------------------------------ [2009-04-30 16:46:10] vincent dot k dot hughitt at nasa dot gov Description: ------------ I wrote a small piece of code using that uses the GD module to apply a color-table to a gray-scale image. In newer versions of PHP, however, the script only outputs grayscale images, with no error message. Furthermore, outputting the contents of imagecolorsforindex shows that the script is still reading the palette properly, so it must have something to do with the next step (imagecolorset). Any ideas? =========================================================== System 1 (non-working): Ubuntu 9.04 Linux 2.6.28-11-generic PHP 5.2.6-3ubuntu4.1 with Suhosin-Patch 0.9.6.2 (cli) (built: Apr 23 2009 14:35:05) gd 2.0.36~rc1~dfsg-3ubuntu1 =========================================================== System 2 (non-working): Fedora 11 Beta Linux 2.6.29.1-111.fc11.i586 PHP 5.2.9 gd 2.0.35 =========================================================== System 3 (WORKING): Ubuntu 8.10 Linux 2.6.27-11-generic PHP 5.2.6-2ubuntu4.1 with Suhosin-Patch 0.9.6.2 (cli) (built: Feb 11 2009 20:38:24) gd 2.0.36~rc1~dfsg-3ubuntu1 =========================================================== (Originally reported downstream at: https://bugs.edge.launchpad.net/ubuntu/+source/php5/+bug/368036) Reproduce code: --------------- /** * Takes a grayscale PNG and modifies it's index to use 256-color * lookup table then outputs it as an 8-bit JPEG image, or 8-bit * paletted PNG. * * Sample image and color-table: * * http://launchpadlibrarian.net/26034594/eit_grayscale.png * http://launchpadlibrarian.net/26034597/ctable_eit304.png */ $gd = imagecreatefrompng("eit_grayscale.png"); $ctable = imagecreatefrompng("ctable_eit304.png"); for ($i = 0; $i <= 255; $i++) { $rgba = imagecolorsforindex($ctable, $i); imagecolorset($gd, $i, $rgba["red"], $rgba["green"], $rgba["blue"]); } imagejpeg($gd, "eit_final.jpg", 75); imagedestroy($gd); imagedestroy($ctable); Expected result: ---------------- Outputs a 8-bit color JPEG. (http://launchpadlibrarian.net/26034598/eit_final_ubuntu810.jpg) Actual result: -------------- Outputs a 8-bit grayscale JPEG. (http://launchpadlibrarian.net/26034602/eit_final_ubuntu904.jpg) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=48123&edit=1
