PHP 水印 - Zubrag

我正在使用 zubrags PHP 水印脚本（附在下面），它的效果很好，除非我尝试使用 PNG-24 作为我的水印。生成的图像带有乱码、不透明的水印。我想知道是否有人可以帮助解释我需要在下面的脚本中更改哪些内容，以便将 PNG-24 作为正确的水印嵌入到图像上？我确实看到了这篇文章：http://www.benholmen.com/blog/2008/12/adding-png-watermarks-to-jpegs-with-php/ http://www.benholmen.com/blog/2008/12/adding-png-watermarks-to-jpegs-with-php/其中提到使用 PHP 的 imagealphablending() 函数来支持 PNG-24。

预先感谢您的任何帮助。非常感谢:)

祖布拉格的水印：

class Zubrag_watermark {

  var $offset_x = 0;
  var $offset_y = 0;
  var $quality = 100;
  var $image_type = -1; // Image type: 1 = GIF, 2 = JPG, 3 = PNG
  var $force_image_type = -1; // Change image type? (-1 = same as original, 1 = GIF, 2 = JPG, 3 = PNG)
  var $save_to_file = true;

  function Zubrag_watermark($image_path='', $offset_x=0, $offset_y=0) {
    $this->setImagePath($image_path);
    $this->setOffset($offset_x, $offset_y);
  }

  function setImagePath($image_path) {
    $this->image_path = $image_path;
  }

  function setOffset($x, $y) {
    $this->offset_x = $x;
    $this->offset_y = $y;
  }

  function ImageCreateFromType($type,$filename) {
   $im = null;
   switch ($type) {
     case 1:
       $im = ImageCreateFromGif($filename);
       break;
     case 2:
       $im = ImageCreateFromJpeg($filename);
       break;
     case 3:
       $im = ImageCreateFromPNG($filename);
       break;
    }
    return $im;
  }

  function ApplyWatermark($watermark_path) {

    $this->watermark_path = $watermark_path;

    // Determine image size and type
    $size = getimagesize($this->image_path);
    $size_x = $size[0];
    $size_y = $size[1];
    $image_type = $size[2]; // 1 = GIF, 2 = JPG, 3 = PNG

    // load source image
    $image = $this->ImageCreateFromType($image_type, $this->image_path);

    // Determine watermark size and type
    $wsize = getimagesize($watermark_path);
    $watermark_x = $wsize[0];
    $watermark_y = $wsize[1];
    $watermark_type = $wsize[2]; // 1 = GIF, 2 = JPG, 3 = PNG



    // load watermark
    $watermark = $this->ImageCreateFromType($watermark_type, $watermark_path);

    // where do we put watermark on the image?
    $dest_x = $size_x - $watermark_x - $this->offset_x;
    $dest_y = $size_y - $watermark_y - $this->offset_y;

    imagealphablending($image, true);
 imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_x, $watermark_y, 100);  

    $this->image = &$image;
    $this->watermark = &$watermark;
    $this->image_type = $image_type;

  } // ApplyWatermark

  function OutputImageInternal($filename='') {

    $im = &$this->image;
    $res = null;

    $image_type = ($this->force_image_type != -1 ? $this->force_image_type : $this->image_type);

    // ImageGIF is not included into some GD2 releases, so it might not work
    // output png if gifs are not supported
    if(($image_type == 1)  && !function_exists('imagegif')) $image_type = 3;

    switch ($image_type) {
      case 1:
        if ($this->save_to_file) {
          $res = ImageGIF($im,$filename);
        }
        else {
          header("Content-type: image/gif");
          $res = ImageGIF($im);
        }
        break;
      case 2:
        if ($this->save_to_file) {
          $res = ImageJPEG($im,$filename,$this->quality);
        }
        else {
          header("Content-type: image/jpeg");
          $res = ImageJPEG($im, NULL, $this->quality);
        }
        break;
      case 3:
        if (PHP_VERSION >= '5.1.2') {
          // Convert to PNG quality.
          // PNG quality: 0 (best quality, bigger file) to 9 (worst quality, smaller file)
          $quality = 9 - min( round($this->quality / 10), 9 );
          if ($this->save_to_file) {
            $res = ImagePNG($im, $filename, $quality);
          }
          else {
            header("Content-type: image/png");
            $res = ImagePNG($im, NULL, $quality);
          }
        }
        else {
          if ($this->save_to_file) {
            $res = ImagePNG($im, $filename);
          }
          else {
            header("Content-type: image/png");
            $res = ImagePNG($im);
          }
        }
        break;
    }

    return $res;

  }

  function Output($type = -1) {
    $this->force_image_type = $type;
    $this->save_to_file = false;
    $this->OutputImageInternal();
  }

  function SaveAsFile($filename, $type = -1) {
    $this->force_image_type = $type;
    $this->save_to_file = true;
    $this->OutputImageInternal($filename);
  }

  function Free() {
    imagedestroy($this->image);
    imagedestroy($this->watermark);
  }

}

更改上面代码中使用的函数 来自： imagecopymerge() 到：图像复制（）

似乎成功了！