How do you strip or filter attributes from a Post’s tags?

Hi
I want to strip attributes that WordPress automatically gives my images.

I’m assuming this can be done after the post has been published, in my templates single.php and functions.php

I have found a great script for this, but my PHP skills are lacking, so I can’t figure out how to apply this function to the content. (the script is below)

What I want to do:
Use ‘Thumbnail’, ‘Medium’, ‘Large’ settings in the image uploader.

But:
Filter out the automatic width and height parameters, and simplify the unique styles WP gives the posts and just give each relative image it’s own class.

Example:
class=”imgThumb”
class=”imgMedium”
class=”imgLarge”

So:
<img class=”alignnone size-large wp-image-379″ title=”8″ src=”http://site.com/wp-content/uploads/image.jpg&#8221; alt=”image” width=”1024″ height=”640″ />

Becomes:
<img class=”imgLarge” title=”8″ src=”http://site.com/wp-content/uploads/image.jpg&#8221; alt=”image” />

Would reaaaaalllly appreciate someone helping me!

Thanks,
Marc

Here is the code I think could do most of the work, but i dont know how to make this talk to WP yet. I got it from here

<?php
function strip_attributes($msg, $tag, $attr, $suffix = "")
{
     $lengthfirst = 0;
     while (strstr(substr($msg, $lengthfirst), "<$tag ") != "") {
          $tag_start = $lengthfirst + strpos(substr($msg, $lengthfirst), "<$tag ");

          $partafterwith = substr($msg, $tag_start);

          $img = substr($partafterwith, 0, strpos($partafterwith, ">") + 1);
          $img = str_replace(" =", "=", $img);

          $out = "<$tag";
          for($i = 0; $i < count($attr); $i++) {
               if (empty($attr[$i])) {
                    continue;
               }
               $long_val =
               (strpos($img, " ", strpos($img, $attr[$i] . "=")) === false) ?
               strpos($img, ">", strpos($img, $attr[$i] . "=")) - (strpos($img, $attr[$i] . "=") + strlen($attr[$i]) + 1) :
               strpos($img, " ", strpos($img, $attr[$i] . "=")) - (strpos($img, $attr[$i] . "=") + strlen($attr[$i]) + 1);
               $val = substr($img, strpos($img, $attr[$i] . "=") + strlen($attr[$i]) + 1, $long_val);
               if (!empty($val)) {
                    $out .= " " . $attr[$i] . "=" . $val;
               }
          }
          if (!empty($suffix)) {
               $out .= " " . $suffix;
          }

          $out .= ">";
          $partafter = substr($partafterwith, strpos($partafterwith, ">") + 1);
          $msg = substr($msg, 0, $tag_start) . $out . $partafter;
          $lengthfirst = $tag_start + 3;
     }
     return $msg;
}

?>