：）实际上，我正在制作一本在线相册，为了完成它，我需要创建一个水印脚本。但它绝对不起作用！我真的不明白为什么。我需要按比例调整水印的大小；我已经做了所有的比率计算，一切似乎都很清楚，但什么都不起作用，请帮帮我！
这是代码：
<?php
// Load the stamp and the photo to apply the watermark to
$stamp = imagecreatefrompng('stamp.png');
$im = imagecreatefromjpeg('531a1251532b0.jpg');
// get the height/width of the stamp image
$sx = imagesx($stamp);
$sy = imagesy($stamp);
$syimg = imagesy($im);
//percentage of the size(4%)
$percent = 4/$syimg;
$sx2 = $sx * $percent;
$sy2 = $sy * $percent;
$posx = (imagesx($im) / 2) - $sx2;
$posy = (imagesy($im) / 2) - $sy2;
//checking (everything is ok!)
//echo "per: ". $percent;
//echo "<br>'n sx: ". $sx2;
//echo "<br>'n posx: ". $posx;
//echo "<br>'n sy: ". $sy2;
//echo "<br>'n posy: ". $posy;
//echo "<br>'n syimg : ". $syimg;
//echo "<br>'n sximg : ". imagesx($im);
// Copy the stamp image onto the photo
// width to calculate positioning of the stamp.
imagecopy($im, $stamp, round($posx), round($posy), 0, 0, round($sx2), round($sy2));
// Output and free memory
header('Content-type: image/jpg');
imagepng($im);
imagedestroy($im);
?>
感谢您今后的回复！
感谢Ryan Vincent和simON的帮助！：）我终于（在经历了许多小时和头痛之后）找到了解决方案，正如你在下面看到的，我发现我的解决方案更简单：
<?php
if(empty($_GET['i'])){
//displays a error image if GET['i'] is empty
$im = imagecreatefrompng("scr/m/e.png");
//keeps the transparency of the picture
imagealphablending( $im, false );
imagesavealpha( $im, true );
// Output and free memory
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
}elseif(!file_exists('img/'.$_GET['i'])){
//displays an error image if the file doesn't exists in the img folder
$im = imagecreatefrompng("scr/m/e.png");
//keeps the transparency of the picture
imagealphablending( $im, false );
imagesavealpha( $im, true );
// Output and free memory
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
}else{
// Load the stamp and the photo to apply the watermark to
$stamp = imagecreatefrompng('scr/m/w.png');
$get = $_GET['i'];
$im = imagecreatefromjpeg('img/'.$get);
// get the height/width of the stamp image
$sx = imagesx($stamp);
$sy = imagesy($stamp);
$sximg = imagesx($im);
//percentage of the size(5%)
$percent = $sximg * 0.15;
//positionnig the stamp to the center
$posx = round(imagesx($im) / 2) - round($percent / 2);
$posy = round(imagesy($im) / 2) - round($percent / 2);
//Create the final resized watermark stamp
$dest_image = imagecreatetruecolor($percent, $percent);
//keeps the transparency of the picture
imagealphablending( $dest_image, false );
imagesavealpha( $dest_image, true );
//resizes the stamp
imagecopyresampled($dest_image, $stamp, 0, 0, 0, 0, $percent, $percent, $sx, $sy);
// Copy the resized stamp image onto the photo
imagecopy($im, $dest_image, round($posx), round($posy), 0, 0, $percent, $percent);
// Output and free memory
header('Content-type: image/jpg');
imagepng($im);
imagedestroy($im);
}
?>
再次感谢您的回复。我希望我的剧本能帮助到和我一样处境的每个人！：）晚安（我是法国人，现在是晚上：3）！