Digital images
Images can be found around us wherever we look; so it is very important to understand how images are represented and how the images' colors are mapped if we want to understand, process, and analyze these images automatically.
Color spaces
We live in a continuous world, so to capture a scene in a discreet digital sensor, a discrete spatial (layout) and intensity (color information) mapping has to happen in order to store the real-world data in a digital image.
The two-dimensional digital image, D(i,j), represents a sensor response value at the pixel indicated by the row number i and column number j, starting from the left upper corner as i=j=0.
To represent colors, a digital image usually contains one or more channels to store the intensity value (color) of each pixel. The most widely used color representation is a one-channel image, also known as a grayscale image, where every pixel is assigned a shade of gray depending on its intensity value: zero is black and the maximum...