How to Improve my php image resizer to support alpha png and transparent GIFs

DenRashZ

New Member
I use this function to resize images but i end up with ugly creepy image with a black background if it's a transparent GIF or PNG with alpha, however it works perfectly for jpg and normal png.\[code\]function cropImage($nw, $nh, $source, $stype, $dest) { $size = getimagesize($source); $w = $size[0]; $h = $size[1]; switch($stype) { case 'gif': $simg = imagecreatefromgif($source); break; case 'jpg': $simg = imagecreatefromjpeg($source); break; case 'png': $simg = imagecreatefrompng($source); break; } $dimg = imagecreatetruecolor($nw, $nh); switch ($stype) { case "png": imagealphablending( $dimg, false ); imagesavealpha( $dimg, true ); $transparent = imagecolorallocatealpha($dimg, 255, 255, 255, 127); imagefilledrectangle($dimg, 0, 0, $nw, $nh, $transparent); break;case "gif": // integer representation of the color black (rgb: 0,0,0) $background = imagecolorallocate($simg, 0, 0, 0); // removing the black from the placeholder imagecolortransparent($simg, $background); break; } $wm = $w/$nw; $hm = $h/$nh; $h_height = $nh/2; $w_height = $nw/2; if($w> $h) { $adjusted_width = $w / $hm; $half_width = $adjusted_width / 2; $int_width = $half_width - $w_height; imagecopyresampled($dimg,$simg,-$int_width,0,0,0,$adjusted_width,$nh,$w,$h); } elseif(($w <$h) || ($w == $h)) { $adjusted_height = $h / $wm; $half_height = $adjusted_height / 2; $int_height = $half_height - $h_height; imagecopyresampled($dimg,$simg,0,-$int_height,0,0,$nw,$adjusted_height,$w,$h); } else { imagecopyresampled($dimg,$simg,0,0,0,0,$nw,$nh,$w,$h); } imagejpeg($dimg,$dest,100); }\[/code\]Example : \[code\]cropImage("300","200","original.png","png","new.png");\[/code\]I use php 5.3.2 and the GD library bundled (2.0.34 compatible) How to make it support transparency? i've added \[code\]imagealphablending()\[/code\] and \[code\]imagesavealpha\[/code\] but it didn't work. Or atlast is there any similar good classes?Thanks
 
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