Write On Pic: Write text on a picture

This class can be used to write text on a picture.

It can open an picture file in the GIF, PNG, JPEG and BMP formats, and write a given text string on the picture.

The colors, opacity, border effect, font size and position of the text are configurable parameters.

The resulting image with the text on it may be stored on a file or served as the current script output in the same set of possible formats as the input picture.