ThinkPHP Image.class.php水印功能支持png原始透明 - 大米CMS官网论坛，大米站长联盟，大米站长之家，大米开发者社区

static function imagecopymerge_alpha($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $pct){
$opacity=$pct;
// getting the watermark width
$w = imagesx($src_im);
// getting the watermark height
$h = imagesy($src_im);
// creating a cut resource
$cut = imagecreatetruecolor($src_w, $src_h);
// copying that section of the background to the cut
imagecopy($cut, $dst_im, 0, 0, $dst_x, $dst_y, $src_w, $src_h);
// inverting the opacity
//$opacity = 100 - $opacity;
// placing the watermark now
imagecopy($cut, $src_im, 0, 0, $src_x, $src_y, $src_w, $src_h);
imagecopymerge($dst_im, $cut, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $opacity);
}
第二步用imagecopymerge_alpha替换原来的imagecopymerge处理，大约83行将
//生成混合图像
imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo['width'], $wInfo['height'], $alpha);
替换为
//生成混合图像
self::imagecopymerge_alpha($sImage, $wImage, $posX, $posY, 0, 0, $wInfo['width'], $wInfo['height'], $alpha);

复制代码