Introduction:
A digital image is a function with discrete and bounded support. Support is multidimensional (Two or three-dimensional) containing a set of discrete-valued pixels. These last can be scalar (Example: grayscale images) or vector (Example: multi-component or color imaging).
The range of possible values varies depending on the type of image considered, a digital image is associated with a rectangular tiling of space. Each element of the tiling called a pixel (Figure 1) is designated by its full coordinates.
Sampling is the process of spatial discretization of an image, it consists of associating for each pixel a unique value, the reduction in the number of pixels of an already discretized image is called sub-sampling.
Quantization consists of limiting the number of different values that each pixel in the image can take.
A digital image is therefore a sampled and quantized image. A two-dimensional (2D) digital image is represented by an array “I” of h-rows and w-columns (See Figure 2).
