Manipulating Images: Where to Start?

[Budger3]

Hi all,

I am working on a web site for a college project. I am using PHP to code with a MySQL database and everything is working nicely. I wouldn't say I'm great at PHP, but I've been able to do a decent job of the forums and private messaging so far, so I'm feeling quite proud of myself... But, I've run into a problem.

I need to make a way for people to upload just one image (we're talking huge, 4-8MB per file) and it to create new images of the following.
- First, it just uploads the original
- Then it clones it and reduces the size and resolution greatly
- Then it clones it and reduces the size a lot more and puts a watermark on it
- Then it clones it and reduces the size even more and puts a watermark on it

I have no clue how to do this and no idea where to start. Can anyone give me a hand?

Tahnks Yall
Budger3

[Weedpacket]

The most obvious place to start is with PHP's [man]image[/man] functions.

[bodzan]

post_max_size and upload_max_filesize setting in php.ini file and the way to change them so you can allow upload of such a huge files...

Without it you can't even start...

[leatherback]

Hey Budger,

Congratulations on the project so far.

Hope this will help you get somewhat further. (I actually re-wrote this this morning, so I am not sure it is completely without typos, but the general functionality should work.

The uploaded filename you can get from the $_FILE[] array, in this case you would want to use this array as the first argument in the function.

(Place print_r($FILE); on top of your page, and you will get an overview of what is in the $FILE array)

function upload_file($file_array, $type, $destination, $new_max_width, $new_max_height)
  {

  switch($type)
    {

case "img" :

   $original_picture = $file_array['file']['name']
   $tmp_picture      = $file_array['file']['tmp_name']
   $new_picture      = $destination;

   $fullPath = $original_picture; 

    // ****************** Test variables / files for correct input *******************************

    if (!file_exists($fullPath) )         // Check wether filesource exists
    {
    return("File doesn't exist in temporary folder on server!");
    // The script has died here
    }

    if( file_exists($new_picture))        // Remove existsing file
    {
    $delete = @unlink($new_picture);
    }

    // ***************** Get file details **************************

    $size = GetImageSize($fullPath);
    $aspectRat = (float)($size[1] / $size[0]);

    // ***************** Calculate new x/y size, maintaining original aspect ratio

    if( ($size[0] <= $new_max_width) && ($size[1] <= $new_max_width) )  // Image < max size
    {
    return;
    }
    else 
    {

    $width_ratio = $size[0] / $new_max_width;
    $height_ratio = $size[1] / $new_max_height;

    if($width_ratio >= $height_ratio)  // width needs to be reduced more
      {
      $newY = $new_max_width * $aspectRat;
      $newX = $new_max_width;
      }
    else
      {
      $newY = $new_max_height;
      $newX = $new_max_height * (1/$aspectRat);
      }
    }

    //create the destination image resource. 

    $destImg = ImageCreateTrueColor($newX, $newY );

    //read the source image (original), use correct function depending on format

    if ($size[2] == 1)
    {
    $sourceImg = ImageCreateFromGIF($fullPath);
    }
    if ($size[2] == 2)
    {
    $sourceImg = ImageCreateFromJPEG($fullPath);
    }
    else if ($size[2] == 3)
    {
    $sourceImg = ImageCreateFromPNG($fullPath);
    }
    else
    {
    return("This file cannot be used. It is not a jpg, gif or png file.<br>");
    die(); // This is a double-trap. Return should have ended execution fo the scriopt already 
    }

    // **************************** Create the new output file *******************

    imagecopyresampled($destImg, $sourceImg, 0, 0, 0, 0, $newX, $newY, $size[0],  $size[1]);
    imagejpeg($destImg, $new_picture, $quality);

    // *************************** Remove the temproary file *********************

    $deletedfile = @unlink($original_picture);

Happy PhP-ing,

J.