PHP GD imagecopy() 上的图像损坏

Question

我在使用 PHP 5.3.3 时遇到了一些奇怪的情况，我正在尝试向图像添加水印。

$body = @imagecreatefromstring($image_data['body']);
imagejpeg($body, null, 85);

返回：https://i.sstatic.net/KJjDi.jpg

$body   = @imagecreatefromstring($image_data['body']);
$logo   = @imagecreatefrompng(APP_ROOT . self::WATERMARK_PATH);

$body_width     = (int) @imagesx($body);
$body_height    = (int) @imagesy($body);

$logo_width     = (int) @imagesx($logo);
$logo_height    = (int) @imagesy($logo);

$image = imagecreatetruecolor($body_width + 4, $body_height + $logo_height);

imagecopy(
    $image, $logo, 
    intval($body_width / 2) - ceil($logo_width / 2), $body_height, 
    0, 0, $logo_width, $logo_height
);

imagejpeg($image, null, 85);

返回：https://i.sstatic.net/nwtqZ.jpg

buuuuuuuuut......如果我添加身体（猫）到图像...

$body   = @imagecreatefromstring($image_data['body']);
$logo   = @imagecreatefrompng(APP_ROOT . self::WATERMARK_PATH);

$body_width     = (int) @imagesx($body);
$body_height    = (int) @imagesy($body);

$logo_width     = (int) @imagesx($logo);
$logo_height    = (int) @imagesy($logo);

$image = imagecreatetruecolor($body_width + 4, $body_height + $logo_height);

imagecopy(
    $image, $body, 
    1, 1, 
    0, 0, $body_width, $body_height
);

imagecopy(
    $image, $logo, 
    intval($body_width / 2) - ceil($logo_width / 2), $body_height, 
    0, 0, $logo_width, $logo_height
);

imagejpeg($image, null, 85);

结果： https://i.sstatic.net/ Xeb73.jpg

正如您在最后一张中看到的那样，图像的底部已损坏或发生了其他情况……发生了什么？

Answer 1

尝试这段代码我发现绝对没有错误：

<?php
$body   = imagecreatefromjpeg('https://i.sstatic.net/KJjDi.jpg');
$logo   = imagecreatefromjpeg('http://b.vimeocdn.com/ps/161/161028_300.jpg');
$body_width     = (int) imagesx($body);
$body_height    = (int) imagesy($body);
$logo_width     = (int) imagesx($logo);
$logo_height    = (int) imagesy($logo);
$image = imagecreatetruecolor($body_width + 4, $body_height + $logo_height);
imagecopy(
    $image, $body, 
    1, 1, 
    0, 0, $body_width, $body_height
);
imagecopy(
    $image, $logo, 
    intval($body_width / 2) - ceil($logo_width / 2), $body_height, 
    0, 0, $logo_width, $logo_height
);
header('Content-Type: image/jpeg');
imagejpeg($image, null, 85);
?>

我想说它与实际图像有关:-？