Digital Image Fundamentals

In an image with 256 shades of gray, each pixel is represented by one byte (8 bits). Here, we only encode the level of brightness, typically using one byte 28 = 256 values. By convention, the value zero represents black (zero brightness), and the value 255 represents white (maximum brightness).

Thus, the digital image is represented in the form of a two-dimensional array containing integer values for grayscale images or triplets of integer values for color images. This array of integer values is the ”genetic code” of the image. As for the figure below, we provide an example of an 8 bpp (bits per pixel) photo.

It is helpful to have an understanding of the 256 shades of gray, as illustrated

in Figure 8.

This process is commonly used to reproduce black and white photos or text.