Draw Blocks: Generate an image with mapped colored squares

This class can be used to generate a picture with mapped colored squares.

It takes as parameters a text string with several rows of characters and an array that defines to which color each character in the string maps.

The class generates an image with rows of squares colored according to the mapping defined parameter text string and color map array.

The generated image is served as the script output in either GIF, PNG or JPEG formats.