Bug #81321 [Opn->Nab]: incorrect image on save

Edit report at https://bugs.php.net/bug.php?id=81321&edit=1 ID: 81321 Updated by: cmb@php.net Reported by: andrei at anleaf dot com Summary: incorrect image on save -Status: Open +Status: Not a bug Type: Bug -Package: *Graphics related +Package: GD related Operating System: CentOs 7.9 PHP Version: 7.4.22 -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: You need to preserve the alpha channel explicitly by calling imagesavealpha()[1], e.g. <?php $im = imagecreatefrompng("orig.png"); imagesavealpha($im, true); imagepng("new.png"); ?> [1] <https://www.php.net/imagesavealpha> Previous Comments: ------------------------------------------------------------------------ [2021-08-02 08:00:07] andrei at anleaf dot com One more png with the problem https://www.dropbox.com/s/1kuirhjgvnfcohs/logo_orig-2.png?dl=0 Its conversion result (wrong) is here https://www.dropbox.com/s/98iklpacpm5ppot/logo-orig-2_new.png?dl=0 ------------------------------------------------------------------------ [2021-08-01 21:30:16] andrei at anleaf dot com Description: ------------ problem with opening and saving some png images using imagecreatefrompng() and then save it using imagepng($image,$file). Image opens OK but when saved, the resulting image has broken alpha channel. Happens with some png images. Input image to test is here https://www.dropbox.com/s/c6ne72bobrt2iz9/logo_orig.png?dl=0 Resulting image with problem is here https://www.dropbox.com/s/xs4b4bv6208hiua/logo_new.png?dl=0 Test script: --------------- $im = imagecreatefrompng("logo_orig.png"); imagepng($im,"logo_new.png"); imagedestroy($im); Expected result: ---------------- saved image should look the same as an input image Actual result: -------------- saved image is completely distorted. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=81321&edit=1