Rotating a picture in PHP once it's saved - php

Question

I have this PHP script that saves a picture on my website. I would like to, once the picture is saved, rotate the picture by 90 degrees if it's not landscape. This a piece of my script:
$uploadfile = 'path/where/to/save/picture.jpg';
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) {
//The code under here is not working
if($_GET['landscape'] == false || $_GET['landscape'] == 'false'){
$img = imagecreatefromjpeg($uploadfile);
$newimg = imagerotate($img, 90.0, 0);
imagejpeg($newimg, $uploadfile);
}
//this is code under here is working
$prev = create_preview($filename, $uploadfile, $ext, true);
}
As you can see I move_uploaded_file() and then I have an if statement that if the picture is not landscape (so landscape == false) I rotate it. Then I create a preview of the picture.
If I comment out the if statement that checks the landscape the code WORKS, so it uploads the picture but it's NOT ROTATED as I want and creates a preview. If I let the if uncommented (like in this case) it seems like it's not saved anymore because when I try to visualize it I see nothing. This means that the code flow goes into the if, then something happens and the picture is not visualized anymore. The problem is in the if statement that rotates the picture.
So there is definitely something wrong in the procedure to rotate the picture, but I don't understand exactly what's wrong, I create the image from the location it has been uploaded to, I rotate it using the PHP function and then recreate the image in the same exact location.
Can anyone of you see where I'm getting this wrong?
Thanks,
Masiar

Answer 1

It's a shame you can't see the error messages. I suggest writing a small test page that will "fake" the iPhone side of things and allow you to test by submitting images without using the phone. Or simply write a short script that will open an image, imagerotate() it and save it, and use that for testing.
Also, as gnud points out, the PHP errors may even already be being written out to a server logfile. (Typically, they'll be somewhere like /var/log/apache/..., but figuring out where they are on your box will be more of a question for SuperUser, I guess...)
Having said that, given all you've said, I suspect that the PHP package for the distribution of Linux you're using does not support the (fairly-heavily-edited) PHP "packaged" version of the GD library. See this enhancement request for Ubuntu for some details.
This means that the imagerotate() function that you're using simply doesn't exist. You'd verify this easily if you enabled error reporting and used a test script.
As a workaround, your options are either to find a version of the GD library that you can install on your box to replace the standard one, or perhaps use a function written in PHP to do the rotation manually.
Alternatively, as Eamorr suggests, you could shell out to a command-line tool like ImageMagick (or maybe use ImageMagick via the PECL ImageMagick library, but that's probably overkill for one rotate.)
As an aside, I believe the iPhone specifically "rotates" photos that it's taken (e.g. in landscape orientation) by setting a flag in the image metadata, rather than actually rotating the image data, so if you're rotating images taken on an iPhone, make sure that you test with images taken in both portrait and landscape orientations, and check that your image rotation is doing the right thing in each case.
If I recall correctly, the photo data is always in portrait orientation, and just has the "landscapeness" set in the EXIF orientation data if the photo was taken with the phone held in landscape orientation. There are different values for if the phone's held upside-down, too.

Answer 2

To flip 180 degrees:
exec('mogrify -flip /path/to/your/picture');
You need to install imagemagick
I'm sure you can figure out how to flip it 90 degrees very easily.