PHP图像调整大小和裁剪有时翻转图像上下颠倒

Question

I have a script that works fine on most images but it is flipping this image upside down:

This Image Will Flip For Some Odd Reason

Here is the script I'm using:

    <?php
$image = imagecreatefromjpeg('photo_4.jpg');
$filename = 'TEMP.jpg';

$thumb_width = 100;
$thumb_height = 100;

$width = imagesx($image);
$height = imagesy($image);

$original_aspect = $width / $height;
$thumb_aspect = $thumb_width / $thumb_height;

if ( $original_aspect >= $thumb_aspect )
{
// If image is wider than thumbnail (in aspect ratio sense)
$new_height = $thumb_height;
$new_width = $width / ($height / $thumb_height);
}
else
{
// If the thumbnail is wider than the image
$new_width = $thumb_width;
$new_height = $height / ($width / $thumb_width);
}

$thumb = imagecreatetruecolor( $thumb_width, $thumb_height );

// Resize and crop
imagecopyresampled($thumb,
$image,
0 - ($new_width - $thumb_width) / 2, // Center the image horizontally
0 - ($new_height - $thumb_height) / 2, // Center the image vertically
0, 0,
$new_width, $new_height,
$width, $height);
imagejpeg($thumb, $filename, 80);

Answer 1

It's because the image is actually upside down. Some of the viewers you are using are looking at the exif data and flipping it for you. Check here... http://imgops.com/https://www.apple.com/v/iphone-5s/gallery/b/images/download/photo_4.jpg#photo-gallery4