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.
Yes, you're right, there is a bug, actually two. It happens that imagecolorallocate() doesn't fill the image if it has been created in true colors. Then if the text is black, it becomes transparent as the background used for the merged text image is also black. A kind of double bug...
I will fix it in the next release. In the meantime, you can change the code as following.
I will fix it in the next release. In the meantime, you can change the code as following.
Replace l.2478-2479:
With: