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Prevent imagejpeg() from saving EXIF data for images (spec. FileDateTime)

Asked 2012-04-30T17:43:22.333
8

Our server is saving EXIF data to every file saved with imagejpeg(). As far as I know, this is not the default behavior (or even possible, from what I've read). But, it is occurring, and due to the FileDateTime information being included (and using the time of save), it is breaking functionality in our upload/approval system (md5_file() returns a different value for the exact same image due to FileDateTime always being different).

Is there a way to prevent imagejpeg() from saving EXIF data for images by default?

Server Information

  • CentOS 5
  • Parallels Plesk Panel 10.4.4
  • GD Version: bundled (2.0.34 compatible)
  • PHP 5.3

Code

<?php
public function upload_book_cover($book, $cover, $filename = NULL, $approved = NULL){
    global $c_consummo, $user;
    $approved = bool($approved, true, true);
    if(filesize($cover)>5242880){
        return false; // Too large;
    }
    $max_width = 450;
    $cover_info = getimagesize($cover);
    if(!$this->is_valid_book_cover_type($cover_info['mime'])){
        return false; // Invalid image type
    }
    $width = $cover_info[0];
    $height = $cover_info[1];
    if($width<200){
        return false; // Too small
    } elseif($width>1500){
        return false; // Too wide
    }
    $original_cover = false;
    switch($cover_info[2]){
        case IMAGETYPE_GIF:
            $original_cover = imagecreatefromgif($cover);
            break;
        case IMAGETYPE_JPEG:
            $original_cover = imagecreatefromjpeg($cover);
            break;
        case IMAGETYPE_PNG:
            $original_cover = imagecreatefrompng($cover);
            break;
        case IMAGETYPE_BMP:
            $original_cover = imagecreatefrombmp($cover);
            break;
    }
    if(!$original_cover){
        return false; // Unsupported type
    }
    if(
php gd exif
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3 Answers

4

No idea why EXIF data is being written - so the following may help you remove it.

One suggestion is to run something as a command on the server - it will need some installation: http://hacktux.com/read/remove/exif - then run throuhg EXEC from PHP.

There's also solution posted here that uses ImageMagick if you also have that installed (or cen get it installed: Remove EXIF data from JPG using PHP (but note warning about colour)

Otherwise, the other suggestion is as above, try turning off the EXIT extension.

Sorry if they don't help, but you did ask for any suggestions.

answered 2012-05-11T11:49:57.997
2

Apparently, GD doesn't like when the path to the input / output file is the same, but the credit isn't mine. To fix, use a new (tmp) file to save the newly created image to:

<?php
...
if(!imagecopyresampled($new_cover, $original_cover, 0, 0, 0, 0, $new_width, $new_height, $width, $height)){
 return false; // Could not copy image
}
// Create a tmp file.
$cover_new = tempnam('/tmp', 'cover-');
// Use $cover_new instead of $cover
if(!imagejpeg($new_cover, $cover_new, 100)){
 return false; // Image could not be saved to tmp file
}
// Use $cover_new instead of $cover
$file_hash = md5_file($cover_new);
$duplicate_book_cover = $this->find_duplicate_book_cover($book, $file_hash);
if($duplicate_book_cover){
 return $duplicate_book_cover;
}
// Use $cover_new instead of $cover
$file_id = $c_consummo->upload_file($cover_new, $filename);
...
answered 2012-05-16T17:08:04.783
0

You could try using imagecreatefromjpeg on the image created with imagejpeg and replacing with the newly created one.

answered 2012-05-09T22:53:47.983

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