php水印代码，php半透明水印支持png透明背景

//原始图像 $dst = "/upload/20140914/20120914040740-0.jpg"; //图片路径 //原始图片信息 $dst_info = getimagesize($dst); switch ($dst_info[2]) { case 1: $dst_im =imagecreatefromgif($dst);break; case 2: $dst_im =imagecreatefromjpeg($dst);break; case 3: $dst_im =imagecreatefrompng($dst);break; case 6: $dst_im =imagecreatefromwbmp($dst);break; default: die("不支持的文件类型1");exit; } //水印图像 $src = "/images/shuiyin.png"; //注意路径要写对 $src_info = getimagesize($src); switch ($src_info[2]) { case 1: $src_im =imagecreatefromgif($src);break; case 2: $src_im =imagecreatefromjpeg($src);break; case 3: $src_im =imagecreatefrompng($src);break; case 6: $src_im =imagecreatefromwbmp($src);break; default: die("不支持的文件类型1");exit; } //半透明格式水印 //$alpha = 50; //水印透明度 //imagecopymerge($dst_im,$src_im,$dst_info[0]-$src_info[0]-10,$dst_info[1]-$src_info[1]-10,0,0,$src_info[0],$src_info[1],$alpha); //支持png本身透明度的方式 imagecopy($dst_im,$src_im,$dst_info[0]-$src_info[0]-10,$dst_info[1]-$src_info[1]-10,0,0,$src_info[0],$src_info[1]); //保存图片 switch ($dst_info[2]){ case 1: imagegif($dst_im,$dst);break; case 2: imagejpeg($dst_im,$dst);break; case 3: imagepng($dst_im,$dst);break; case 6: imagewbmp($dst_im,$dst);break; default: die("不支持的文件类型2");exit; } //销毁gd库对象 imagedestroy($dst_im); imagedestroy($src_im); 复制代码