Digital Image Processing NET 404) )

Introduction and Overview

Chapter 1 2012

Teacher: Remah W. AlKhatib

lecture will cover: What is a digital image? What is digital image processing? History of digital image processing State of the art examples of digital image

processing Key stages or components in digital image

processing

Contents

Image

A 2D function f (x, y) that can be observed by human visual system

x and y are spatial (Plane) coordinates

Amplitude of f at a point is intensity or gray level of image at that point

What is an image?

Also called “raster or pixel maps” representation

An image is broken up into a grid

What is an image? Thebitmap representation

A digital image is a representation of a two dimensional image as a finite set of digital values, called picture elements or pixels

What is a Digital Image?

Pixel values typically represent gray levels, colors, heights, opacities etc

Digitization implies that a digital image is an approximation of a real scene

What is a Digital Image?(cont…)

Common image formats include: 1sample per point (B&W or Grayscale) 3 samples per point (Red, Green, and Blue) 4 samples per point (Red, Green, Blue, and

“Alpha”, a.k.a. Opacity)

What is a Digital Image?(cont…)

For most of this course we will focus on grey-scale images

Color images have 3 values per pixel; monochrome images have1 value per pixel.

Digital Image

Digital image processing Refers to processing digital images by

means of operations on digital computer. Digital image processing focuses on two

major tasks: Improvement of pictorial information for

human interpretation Processing of image data for storage,

transmission and representation for autonomous machine perception

What is Digital ImageProcessing?

Computer Graphics The creation of images. Image Processing and Image Analysis Mainly concerned with interpreting a given

image The enhancement or other manipulation of

the image The result of which is usually another images.

Image Understanding (Computer Vision) The analysis of image content.

Several fields deal withimages

Image processing Disciplines

A Historical Overview of DIP

Newspaper industry used Bartlane cable picture transmission system to send pictures by submarine cable between London and New York in 1920s

Early Improvement

The number of distinct gray levels coded by Bartlane systemwas improved from 5 to 15 by the end of 1920s

The images in previous slides are digital; but they are NOT considered as the results of DIP

What do we mean by Digital Image Processing

Processing digital images by a digital computer

The Born of Digital Computers

Acquisition Digital cameras, scanners MRI and Ultrasound imaging Infrared and microwave imagingTransmission Internet, wireless communication Display Printers, LCD monitor, digital TV

The Boom of Digital Imagesin the Last 20 Years

Soar Into Outer Space

Extend the capabilities of human vision systems• From visible spectrum to non-visible

electromagnetic power spectrum• From close-distance sensing to remote sensing

A Physical Perspective of ImageAcquisition

Visible (I): Photography

Visible (II): Motion Pictures

Visible (III): Law Enhancementand Biometrics

Visible (IV): Light Microscopy

Visible (V): Remote Sensing

Beyond Visible (I): ThermalImages

Beyond Visible (II): Radar Images

Beyond Visible (III): MRI andAstronomy

Beyond Visible (IV): MedicalDiagnostics