1.4 Consider the representation for pictures described in Section 1.4, where each dot (pixel) in the picture is represented by three bytes, for the red, green, and blue components of the color at that dot. How many bytes does it take to represent a 640 by 480 picture, a common picture size on the Web? How many bytes does it take to represent a 1024 by 768 picture, a common screen size? (What do you think is meant now by a "three megapixel" camera?)