What is Digital image processing

An image may be defined as a two dimensional function, f(x,y), where x and y are spatial coorindates, and the amplitude of f at any pair of coordinatores (x,y) is called the intensity or gray level of the image at that point. When x,y and the amplitude values of f are all finite, discrete quanitites, we call the image a digital image. A digital image is composed of a finite number fo elements, each of which has a particular location and value. These elements are referred to as picture elements,image elements, pels and pixels. Pixel is the most widely used term.

Unlike humans, who are limited to the visual band of the electromagnetic (EM) spectrum, imaging machines cover almost the entire EM spectrum, ranging from gamma to radio waves. They can operate also on images generated by sources that humans are not accustomed to associating with images. These include ultrasound, electron microscopy and computer generated images. These include ultrasound, electron microscopy and computer generated images. Thus DIP encompases a wide and varied field of applications.

There are 3 type of computerized processes: Low-mid-high. Low level processes involve primitive operations such as reduce noise, contrast enhancement and image sharpening. Here both the input and output are images. Mid processes on images involve tasks such segmenetation (partitioning images into regions or objects), description of those objects to reduce them to a form suitable for computer processing and classification of individual objects. Here input is image but output is the attributes extracted from the images. High level involves "making sense " of an ensemble of recognized objects, as in image analysis, performing cognitive functions normally associated with human vision.