note 69058 added to function.imagealphablending

"If imagealphablending os set to true and you want to merge two images, you are left with no transparency. If it is set to false, only the transparency of the second image is respected, causing no parts of the first image to be shown. To solve this use the following function:" dscharrer at gmail dot com offered this without a use example, so here is one: <? $flag = imagecreatefrompng('a.png'); $mask = imagecreatefrompng('b.png'); imagealphablending($flag, 1); imagealphablending($mask, 1); $i= array($flag, $mask); // here is the array of images, using the above specified $flag and $mask images $s = imagemergealpha($i); header("Content-type: image/png"); imagepng($s); //Merge multiple images and keep transparency //$i is and array of the images to be merged: // $i[1] will be overlayed over $i[0] // $i[2] will be overlayed over that // ... //the function returns the resulting image ready for saving function imagemergealpha($i) { //create a new image $s = imagecreatetruecolor(imagesx($i[0]),imagesy($i[1])); //merge all images imagealphablending($s,true); $z = $i; while($d = each($z)) { imagecopy($s,$d[1],0,0,0,0,imagesx($d[1]),imagesy($d[1])); } //restore the transparency imagealphablending($s,false); $w = imagesx($s); $h = imagesy($s); for($x=0;$x<$w;$x++) { for($y=0;$y<$h;$y++) { $c = imagecolorat($s,$x,$y); $c = imagecolorsforindex($s,$c); $z = $i; $t = 0; while($d = each($z)) { $ta = imagecolorat($d[1],$x,$y); $ta = imagecolorsforindex($d[1],$ta); $t += 127-$ta['alpha']; } $t = ($t > 127) ? 127 : $t; $t = 127-$t; $c = imagecolorallocatealpha($s,$c['red'],$c['green'],$c['blue'],$t); imagesetpixel($s,$x,$y,$c); } } imagesavealpha($s,true); return $s; } ?> ---- Server IP: 83.138.144.80 Probable Submitter: 80.45.66.80 ---- X-Spam-Status: No, hits=3.1 required=5.0 tests=DATE_MISSING,FROM_NO_LOWER autolearn=no version=2.64 ---- Manual Page -- http://www.php.net/manual/en/function.imagealphablending.php Edit -- https://master.php.net/note/edit/69058 Del: integrated -- https://master.php.net/note/delete/69058/integrated Del: useless -- https://master.php.net/note/delete/69058/useless Del: bad code -- https://master.php.net/note/delete/69058/bad+code Del: spam -- https://master.php.net/note/delete/69058/spam Del: non-english -- https://master.php.net/note/delete/69058/non-english Del: in docs -- https://master.php.net/note/delete/69058/in+docs Del: other reasons-- https://master.php.net/note/delete/69058 Reject -- https://master.php.net/note/reject/69058 Search -- https://master.php.net/manage/user-notes.php