Bitmap images consist of matrices of numbered points
with two dimensions for grayscale and three dimensions
for RGB color images. The grayscale images, also called
intensity images, contain numbered values at these points,
called pixels, between 0 for black and 255 for white,
which can be represented as 8-bit binary strings (28
=
256). The numbers between represent gradient gray values
between black and white. The RGB, abbreviated for
Red, Green and Blue, images are actually three two-dimension
image layers, a red, a green and a blue layer, that are
combined to produce the full color image. Each layer of a
color image also contains values from 0 for black to 255
for the lightest shade of the color. The RGB color scheme is
referred to as an additive scheme because adding the effective
value of the three layers usually produces a lighter
color at that pixel.