Question

I have following code

 // load image and get image size
  $img = imagecreatefrompng( "{$pathToImages}{$fname}" );

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


  // calculate thumbnail size
  $new_width = $imageWidth;
  $new_height = 500;

  // create a new temporary image
  $tmp_img = imagecreatetruecolor( $new_width, $new_height );

  // copy and resize old image into new image 
  imagecopyresized( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );

It works fine with some images..but with certain images it shows an error like

Warning: imagecreatefromjpeg() [function.imagecreatefromjpeg]: gd-jpeg: JPEG library reports unrecoverable error: 

Warning: imagesx() expects parameter 1 to be resource, boolean given

Warning: imagesy() expects parameter 1 to be resource, boolean given

I have also enabled

gd.jpeg_ignore_warning = 1

in php.ini

Any help appreciated.

Answer 1

According to a blog post from (Feb 2010) its a bug in the implementation of imagecreatefromjpeg which should return false but throws an error instead.

The solution is to check for the filetype of your image (I removed the duplicate call to imagecreatefromjpeg because its totally superfluous; we already check for right file type before and if an error occurs due to some other reason, imagecreatefromjpeg will return false correctly):

function imagecreatefromjpeg_if_correct($file_tempname) {
    $file_dimensions = getimagesize($file_tempname);
    $file_type = strtolower($file_dimensions['mime']);

    if ($file_type == 'image/jpeg' || $file_type == 'image/pjpeg'){
        $im = imagecreatefromjpeg($file_tempname);
        return $im;
    }
    return false;
}

Then you can write your code like this:

$img = imagecreatefrompng_if_correct("{$pathToImages}{$fname}");
if ($img == false) {
    // report some error
} else {
    // enter all your other functions here, because everything is ok
}

Of course you can do the same for png, if you want to open a png file (like your code suggests). Actually, usually you will check which filetype your file really has and then call the correct function between the three (jpeg, png, gif).