我正在学习如何拍摄上传的图像并创建两个调整大小的副本。我让它工作，以创建一个调整大小的副本罚款。
list($width,$height,$type) = getimagesize($file);
if($width>90){
$asprat = 90 / $width;
$thbwid = round($asprat * $width);
$thbhei = round($asprat * $height);
$asprat = 800 / $width;
$optwid = round($asprat * $width);
$opthei = round($asprat * $height);
}
elseif($height>90){
$asprat = 90 / $height;
$thbwid = round($asprat * $width);
$thbhei = round($asprat * $height);
$asprat = 600 / $width;
$optwid = round($asprat * $width);
$opthei = round($asprat * $height);
}
else{
$thbwid = $width;
$thbhei = $height;
$optwid = $width;
$opthei = $height;
}
$thbout = imagecreatetruecolor($thbwid,$thbhei);
$optout = imagecreatetruecolor($optwid,$opthei);
if($type==2){
$thbsrc = imagecreatefromjpeg($TARGET_PATH);
imagecopyresampled($thbout,$thbsrc,0,0,0,0,$thbwid,$thbhei,$width,$height);
imagejpeg($thbout,$thbpath,80);
imagedestroy($thbout);
/* IF THIS CODE IS OMITTED IT WORKS FOR CREATING A SINGLE IMAGE
$optsrc = imagecreatefromjpeg($TARGET_PATH);
imagecopyresampled($optout,$optsrc,0,0,0,0,$optwid,$opthei,$width,$height);
imagejpeg($optout,$optpath,80);
imagedestroy($optout);
*/
}
else{
$imgsrc = imagecreatefrompng($TARGET_PATH);
imagecopyresampled($thbout,$imgsrc,0,0,0,0,$thbwid,$thbhei,$width,$height);
imagepng($thbout,$thbpath,2);
imagedestroy($thbout);
/* IF THIS CODE IS OMITTED IT WORKS FOR CREATING A SINGLE IMAGE
imagecopyresampled($optout,$imgsrc,0,0,0,0,$optwid,$opthei,$width,$height);
imagepng($optout,$optpath,2);
imagedestroy($optout);
*/
}
当运行时（没有注释），我看到了输出。有人能帮我吗？
����JFIF��;CREATOR: gd-jpeg v1.0 (using IJG JPEG v62), quality = 80 ��C %# , #&')*)-0-(0%()(��C (((((((((((((((((((((((((((((((((((((((((((((((((((��� "�� ���}!1AQa"q2���#B��R��$3br� %&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz��������������������������������������������������������������������������� ���w!1AQaq"2�B���� #3R�br� $4�%�&'()*56789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz��������������������������������������������������������������������������?Ԉ;t9ڞpy�:� ���p ��T�Ȥ�%U�+���*��ד��? Q���A'���E$�i=�N�xG�W9�~� ��h�y��:5��.H�3�� 2�$�{�⦀<�UJw#s�ׁ@�7�)Wy88'�"�$��ҩ���hO���T�%rhp�G�J��dg��?��sS23��qN*�h ��B�8��z��w�� r.㌐Gz�dV�=x50�#�?���� ~���)[���,Ӗ_�~��Q�@ۚb#���ʬ"wbK悥��4܀Ys�E>U"p7��?
运行第二个imagejpeg时$optpath的值是多少？如果它是unset/null，imagejpeg（）将简单地将原始JPEG数据输出到浏览器，这就是您所看到的。如果你在调用imagejpeg之前包含了一个header('Content-type: image/jpeg')，你可能真的可以看到图片本身。
在脚本顶部添加以下代码：
header('Content-Type: image/jpeg');
文档：页眉imagejpeg