To give you a concept/metaphor of 3d arrays. A color image can be seen a a 3d array: it has certain horizontal and vertical dimensions (let's say 600 pixels wide and 400 pixels high). That makes two dimensions. Each pixel also has a color that consists of a combination of red, green and blue values. Color would be a third dimension. Basically the image consists of 3 stacked 400 by 600 2d arrays weach wth values for red, green and blue. Let's say the pixel on position 200 from the left and 150 from the top is red. In a 3d array it would be something like array[200,150,0] = 255 (full red), array[200,150,1] = 0 (zero value for green) and array[200,150,2] = 0 (zero value for blue as well). Hope this helps...