Misusing imageData!
The topics in the LiveCode online tutorials involve manipulation of the imageData, for example, turning a colored image into a grayscale one. (That particular example is located at: http://lessons.runrev.com/s/lessons/m/4071/l/25371-vision-how-do-i-convert-a-color-image-to-grayscale.) We're not going to do that here. Instead, we'll use the values in the image, the mask, and the alpha, to achieve some neat things that don't change the image at all. In fact, in some cases we won't even see the image!
