Why is the rotated image the same aspect ratio? - php

Question

I'm using some PHP code from jquery file upload and I'm trying to rotate an image prior to saving it. Below is my function call:
public function CreateThumb($file_name, $options){
$file_path = $options['src_dir'].$file_name;
$new_file_path = $options['dst_dir'].$file_name;
list($img_width, $img_height) = #getimagesize($file_path);
if (!$img_width || !$img_height) {
return false;
}
$scale = min(
$options['max_width'] / $img_width,
$options['max_height'] / $img_height
);
$new_width = $img_width * $scale;
$new_height = $img_height * $scale;
$new_img = #imagecreatetruecolor($new_width, $new_height);
switch (strtolower(substr(strrchr($file_name, '.'), 1))) {
case 'jpg':
case 'jpeg':
$src_img = #imagecreatefromjpeg($file_path);
$write_image = 'imagejpeg';
$image_quality = isset($options['jpeg_quality']) ?
$options['jpeg_quality'] : 95;
break;
case 'gif':
#imagecolortransparent($new_img, #imagecolorallocate($new_img, 0, 0, 0));
$src_img = #imagecreatefromgif($file_path);
$write_image = 'imagegif';
$image_quality = null;
break;
case 'png':
#imagecolortransparent($new_img, #imagecolorallocate($new_img, 0, 0, 0));
#imagealphablending($new_img, false);
#imagesavealpha($new_img, true);
$src_img = #imagecreatefrompng($file_path);
$write_image = 'imagepng';
$image_quality = isset($options['png_quality']) ?
$options['png_quality'] : 9;
break;
default:
$src_img = null;
}
$src_img = imagerotate($src_img, 90, 0) ;
$success = $src_img && #imagecopyresampled(
$new_img,
$src_img,
0, 0, 0, 0,
$new_width,
$new_height,
$img_width,
$img_height
) && $write_image($new_img, $new_file_path, $image_quality);
// Free up memory (imagedestroy does not delete files):
#imagedestroy($src_img);
#imagedestroy($new_img);
return $success;
}
The image gets rotated but it still maintains it's original aspect ratio and is cropping the photo. Any idea what I'm doing wrong?

Answer 1

Your problem is in how you set the new values:
$new_width = $img_width * $scale;
$new_height = $img_height * $scale;
Should be, in case of a 90 degrees rotation:
$new_width = $img_height * $scale; // reverse height and width
$new_height = $img_width * $scale; // reverse height and width
Edit: And as the original image is rotated, the old width and height have to be reversed:
$success = $src_img && #imagecopyresampled(
$new_img,
$src_img,
0, 0, 0, 0,
$new_width,
$new_height,
$img_height, // reverse width and height
$img_width // reverse width and height
) && $write_image($new_img, $new_file_path, $image_quality);

Answer 2

Just a note: if you are going to use that many #'s to ignore errors, you might as well just put error_reporting(0); at the start of the code.
Secondly, the reason that I saw for the lack of change in pixel ratio is because your $scale is backwards. You have it saying scale = Whole/Part which will almost always give you a value greater than 1 (increasing pixel ratio) unless the max size is smaller than the image size. You'll want it to be scale = Part/Whole So its a decimal ratio (ie 100px/400px, scale = .25).
Good Luck!