//php自带函数 getimagesize()

$img_info = getimagesize('test.jpg');

$img_info = getimagesize('test.jpg');
echo '<pre>';
print_r($img_info);

print_r($img_info);

输出：

Array

(

[0] => 170

[1] => 254

[2] => 2

[3] => width="170" height="254"

[bits] => 8

[channels] => 3

[mime] => image/jpeg

)

这次要用到的就是第四个元素了