Image Processing

From TechnologicalWiki

Introduction

Image processing is a type of signal processing which input is an image. Normally it is a digital image but it's possible to do it over optical and analog images. There are thousands of applications which need a perfect image as input, to extract information from it. Every day, we can see examples of this in the street. The Image recognition is a clear example of image processing ( e.g. reading of code bars in a supermarket ). In the process of getting the image a losing of quality of the image can be produced due to multiple factors.

[edit] The Image Processing process

The first step in the Image Processing process is to get the image. Normally, the image is obtained through a video camera or a photograph camera. When the image has been got, the image processing process is starting. Modern digital technology has made it possible to manipulate multi-dimensional signals with systems that range from simple digital circuits to advanced parallel computers. The goal of this manipulation can be divided into three categories:

• Image Processing image in -> image out

• Image Analysis image in -> measurements out

• Image Understanding image in -> high-level description out

In the process of processing images are not always going to want to implement the three categories of image manipulation, but if we want to apply every one, the process will be as follows:

                  Image Processing >> Image Analysis >> Image Understanding

[edit] Preambles about the image

An image can be understood as a set of values which are obtained through a function of two real variables, for example, a(x,y) with a as the amplitude (e.g. brightness) of the image at the real coordinate position (x,y). In short, an image can be seen as a bidimensional array in which, the cell represent a position of an image. Thus, if a function is applies over a image, the content of the cell represents the value of that function in that point of the image.