Question

I have a php script I’m using to convert an uploaded image into half it’s quality so I can save server space, but it isn’t working I’m new to PHP so hopefully someone can help me where I am going wrong.

if(isset($_FILES['t1']['name'])){
    $file = rand(0, 10000000).$_FILES['t1']['name'];
    if (move_uploaded_file($_FILES['t1']['tmp_name'], $file)) {
        if($fp = fopen($file,"rb", 0))
        {
           $picture = fread($fp,filesize($file));
           fclose($fp);
           $img = imagecreatefrompng($file);
           imagepng($img, $file, 6); //6 quality setting
           imagedestroy($img);
           $tag1 = '<img src="'.$file.'" alt="" class="default" />';
//unlink($file);
echo "<script>$(document).ready(function() {var write = $('.item:nth-child(1)').html();localStorage.item1Pantry = write;});</script>";      
        }
    }


}

Answer 1

PNG is lossless compression. When you set “quality” to 6, you are really just using a mediocre compression method, likely taking up more space. Use 9 for the highest compression (at the expense of slightly more CPU usage, which is hardly noticeable unless you’re doing batch processing).

You might also look into Yahoo!’s image compression, for more lossless optimizations.

Also, you really shouldn’t be allowing users to specify file names, even in part. You wouldn’t be too pleased if someone uploaded remote_control_script.php. Never trust what users upload.