class.upload.php is a powerful and mature PHP class to manage uploaded files, and manipulate images in many ways. The script is available under a GPL license.
more info about the class
input type="text" size="32" name="my_dynamic_text" id="my_dynamic_text" value="Source: "
It works perfectly! I added this line into index.html:
Now, it's possible to print the source on the picture.
Next, i gonna try your donate button.