通过gd库为图片添加透明水印
Friday, March 12th, 2004注：需GD 2.0以上才能有透明效果。
<?php
header (”Content-type: image/png”);
$logoImage = ImageCreateFromPNG(’test.png’);
$photoImage = ImageCreateFromJpeg(’back.jpg’);
ImageAlphaBlending($photoImage, true);
$logoW = ImageSX($logoImage);
$logoH = ImageSY($logoImage);
ImageCopy($photoImage, $logoImage, 0, 0, 0, 0, $logoW, $logoH);
ImageJPEG($photoImage); // output to browser
ImageDestroy($photoImage);
ImageDestroy($logoImage);
?>