在imagecreatetruecolor（）之后：
<?php// ... Before imagecreatetruecolor()$dimg = imagecreatetruecolor($width_new, $height_new); // png ?: gif// start changesswitch ($stype) { case 'gif': case 'png': // integer representation of the color black (rgb: 0,0,0) $background = imagecolorallocate($dimg , 0, 0, 0); // removing the black from the placeholder imagecolortransparent($dimg, $background); // turning off alpha blending (to ensure alpha channel information // is preserved, rather than removed (blending with the rest of the // image in the form of black)) imagealphablending($dimg, false); // turning on alpha channel information saving (to ensure the full range // of transparency is preserved) imagesavealpha($dimg, true); break; default: break;}// end changes$wm = $w/$nw;$hm = $h/$nh;// ...
