Image resizing in php? Can't get it to work - php

Question

I have this code that I have tried creating and don't know what I am doing wrong.
// SET ERROR FLAG
$error = false;
// MAKE SURE FILE IS AN IMAGE
if (!list($width, $height) = getimagesize($_FILES['avatar']['tmp_name'])) {
$error = true;
}
// MAKE SURE FILE COMES FROM FORM
if (!is_uploaded_file($_FILES['avatar']['tmp_name'])) {
$error = true;
}
// MAKE SURE FILESIZE IS NOT OVER 1MB
if (filesize($_FILES['avatar']['tmp_name']) > 1048576) {
$error = true;
}
// TARGER TO SAVE FILE AND CHANGE FILENAME AND FILE TYPE
$target = 'images/avatars/' . md5($user['id']) . '.gif';
// IMAGE RATIO AND RESIZING
$imgRatio = $width / $height;
if ($imgRatio > 1) {
$newWidth = 200;
$newHeight = 200 / $imgRatio;
} else {
$newWidth = 200 * $imgRatio;
$newHeight = 200;
}
$imgResized = imagecreatetruecolor($newWidth, $newHeight);
$newImg = imagecreatefromgif($_FILES['avatar']['tmp_name']);
$newImg = imagecopyresized($imgResized, $newImg, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
// SUCCESSFULL IMAGE UPLOAD
if (!$error && move_uploaded_file($newImg, $target)) {
echo '<p>Your avatar was uploaded successfully.</p>';
// ERROR UPLOADING IMAGE
} else {
echo '<p>There was an error uploading your avatar.</p>';
}
It always fails I cannot get the resizing to work, even a link to a good tutorial will suffice,
Happy new year!!

Answer 1

I think the problem is that you use GD to open the temporary image file:
$newImg = imagecreatefromgif($_FILES['avatar']['tmp_name']);
$newImg = imagecopyresized($imgResized, $newImg, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
And then you try to move the temporary avatar file with move_uploaded_file without freeing GD resource and also discarding all the work done with GD (the resizing I mean, and I can add here you have to use resample instaead of resize method).
if (!$error && move_uploaded_file($newImg, $target)) {
The code moves the temporary uploaded file (currently opened by GD and however not physically altered by your GD work, so not resized) to the $target path.
Edit. Now I see more errors with your code. You cannot do:
$newImg = imagecopyresized($imgResized, $newImg, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
Because imagecopyresized do not returns anything but true or false. It simply copy one portion of a source image to a different destination resource. It do not return a resource itself!
Finally. The correct workflow to the what you want to do is:
Check the uploaded file if it's ok for you (and you do it good, it seems).
Create a $img GD resource opening the uploaded file with imagecopyresized.
Create an empty destination resource $newImg with imagecreatetruecolor.
Resize or resample using imagecopyresized or imagecopyresampled to copy source image to destination resource.
Save destination resource into a GIF file using imagegif.
Discard temporary source uploaded image.
You can learn more googling something like php gd resize uploaded images. Tons of tutorial will be one click far from you.

Answer 2

The code itself looks alright, however there could be a number reasons why it fails. Some debug output would be helpful. Some general pointers:
check that the path for the tmp_name is set and readable
check your php settings for post_max_size, it may be set very low or not set at all.
in your code you are only handling gif type images (imagecreatefromgif), you may need to check for the filetype prior to reading from the image resource
check that GD is properly installed in your php installation (phpinfo(); in a php script or php -i from command line should display it as acticated)
That being sad, add some error messages to your output so we can help further.