尝试放水印章不一致

Question

我试图设置制作水印的程序。

代码：

//添加水印

      // Load the stamp and the photo to apply the watermark to
      $stamp = imagecreatefrompng('./uploads/waterstamp.png');

      // Set the margins for the stamp and get the height/width of the stamp image
      $marge_right = 10;
      $marge_bottom = 10;
      $sx = imagesx($stamp);
      $sy = imagesy($stamp);

      // Copy the stamp image onto our photo using the margin offsets and the photo 
      // width to calculate positioning of the stamp. 
      imagecopy($rotate, $stamp, imagesx($rotate) - $sx - $marge_right, imagesy($rotate) - $sy - $marge_bottom, 0, 0, imagesx($stamp), imagesy($stamp));

      // Output and free memory
      imagejpeg($rotate, $filename);
      imagedestroy($source);
      imagedestroy($rotate);

它有效，但不一致。水印在右边。在其中一张照片中看起来是正确的，但在一张照片中它是一个白色的边框。我不得不附上显示问题的屏幕截图。

有什么想法吗？