How to add watermark to PHP images,

The example in this article describes how to add watermark to PHP images. Share it with everyone for your reference, the details are as follows:

<&#63;php
echo img_water_mark("2008112023204423477802.gif", "copyImg.png", $savepath=null, $savename="123.gif", $positon=2, $alpha=60);
/**
 * 圖片加水印(適用于png/jpg/gif格式)
 * 
 * @author flynetcn
 *
 * @param $srcImg 原圖片
 * @param $waterImg 水印圖片
 * @param $savepath 保存路徑
 * @param $savename 保存名字
 * @param $positon 水印位置 
 * 1:頂部居左, 2:頂部居右, 3:居中, 4:底部局左, 5:底部居右 
 * @param $alpha 透明度 -- 0:完全透明, 100:完全不透明
 * 
 * @return 成功 -- 加水印后的新圖片地址
 *     失敗 -- -1:原文件不存在, -2:水印圖片不存在, -3:原文件圖像對(duì)象建立失敗-4:水印文件圖像對(duì)象建立失敗, -5:加水印后的新圖片保存失敗
 */
function img_water_mark($srcImg, $waterImg, $savepath=null, $savename=null, $positon=5, $alpha=30)
{
  $temp = pathinfo($srcImg);
  $name = $temp['basename'];
  $path = $temp['dirname'];
  $exte = $temp['extension'];
  $savename = $savename &#63; $savename : $name;
  $savepath = $savepath &#63; $savepath : $path;
  $savefile = $savepath .'/'. $savename;
  $srcinfo = @getimagesize($srcImg);
  if (!$srcinfo) {
    return -1; //原文件不存在
  }
  $waterinfo = @getimagesize($waterImg);
  if (!$waterinfo) {
    return -2; //水印圖片不存在
  }
  $srcImgObj = image_create_from_ext($srcImg);
  if (!$srcImgObj) {
    return -3; //原文件圖像對(duì)象建立失敗
  }
  $waterImgObj = image_create_from_ext($waterImg);
  if (!$waterImgObj) {
    return -4; //水印文件圖像對(duì)象建立失敗
  }
  switch ($positon) {
  //1頂部居左
  case 1: $x=$y=0; break;
  //2頂部居右
  case 2: $x = $srcinfo[0]-$waterinfo[0]; $y = 0; break;
  //3居中
  case 3: $x = ($srcinfo[0]-$waterinfo[0])/2; $y = ($srcinfo[1]-$waterinfo[1])/2; break;
  //4底部居左
  case 4: $x = 0; $y = $srcinfo[1]-$waterinfo[1]; break;
  //5底部居右
  case 5: $x = $srcinfo[0]-$waterinfo[0]; $y = $srcinfo[1]-$waterinfo[1]; break;
  default: $x=$y=0;
  }
  imagecopymerge($srcImgObj, $waterImgObj, $x, $y, 0, 0, $waterinfo[0], $waterinfo[1], $alpha);
  switch ($srcinfo[2]) {
  case 1: imagegif($srcImgObj, $savefile); break;
  case 2: imagejpeg($srcImgObj, $savefile); break;
  case 3: imagepng($srcImgObj, $savefile); break;
  default: return -5; //保存失敗
  }
  imagedestroy($srcImgObj);
  imagedestroy($waterImgObj);
  return $savefile;
}
function image_create_from_ext($imgfile)
{
  $info = getimagesize($imgfile);
  $im = null;
  switch ($info[2]) {
  case 1: $im=imagecreatefromgif($imgfile); break;
  case 2: $im=imagecreatefromjpeg($imgfile); break;
  case 3: $im=imagecreatefrompng($imgfile); break;
  }
  return $im;
}
&#63;>

Readers who are interested in more PHP-related content can check out the special topics of this site: "Summary of PHP graphics and image operation skills", "Complete of PHP array (Array) operation skills", "Summary of PHP mathematical operation skills", "php Summary of Date and Time Usage", "Introduction Tutorial on PHP Object-Oriented Programming", "Summary of PHP String Usage", "Introduction Tutorial on PHP MySQL Database Operation" and "Summary of Common PHP Database Operation Skills"

I hope this article will be helpful to everyone in PHP programming.