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INTRODUCTION

One picture

is worth

more than ten thousand words

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Image & Video Data

Image: Image refers to a two dimensional light intensity

function denoted by f(x,y) - x and y denote thespatial co-ordinates.

The magnitude of f( ) at spatial co-ordinates (x,y)gives the intensity of image at that point.

olor Image ! " samples per pixel Intensity (#ray level image) ! $ sample per pixel %inary Image ! $ sample per pixel

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Image: Examples

Coloured Image

Gray level Image

Binary Image

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What is Digital Image Processing Processing of a picture or image by digital

computer

But computer processes only digital data.So we need a digital image.

Continuous

Image

Digital

image

Sampling and

quantization

Obtaining a digital Image :

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Sampling !uantization Digitization of t"e spatial co#ordinates $%&y'

is called image sampling.

("e amplitude digitization is called gray#

le)el quantization

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The Digital Image A digital image is a representation of a two-dimensional image as a

finite set of digital vales! called pictre elements or pi"els

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The Digital Image

Digitization implies t"at a digital image is an

appro%imation of a real scene

# pi"el

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*+,%*+, ,-%,-

$ampling

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*+,%*+, *+, le)els *+,%*+, * le)els

%antisation

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*+,%*+, *+, le)els *+,%*+, * le)els

%antisation

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A t&pical digital image processing se'ence

/ecord

outputDisplay

ob0ect obser)e

Imaging

systems

digitize

Sample and

quantize

store

Digitalstorage

$dis1'

process

Digital

computer

/efres"

2store

On#line

buffer

Image 3cquisition Processing Display2Storage2

(ransmission

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Image Ac'isition Images are generated by t"e combination of

an illumination source and t"e reflection or

absorption of energy from t"at source by t"eelements of t"e scene being imaged.

eg. 4isible lig"t source illuminates a common e)eryday #D

scene. (o get a *#D picture of t"e scene we can use a

camera w"ic" contains lig"t sensors.

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Image Ac'isition Cont( ("e reflected lig"t from t"e scene being

imaged is focused by t"e camera lens.

5ig"t falls on t"e sensing material $a CCD

array' and produces electrical signals

proportional to t"e lig"t intensity

3n 32D con)erter con)erts t"is signal to a

set of discrete numbers. $6ray le)el

quantization'.

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Image Ac'isition Cont( ("e illumination may originate from a source

of electromagnetic energy suc" as radar&

infrared& 7#ray8 Scene elements can be familiar ob0ects or

may be a molecule& buried roc1 formations&

"uman brain8 Depending on t"e nature of source&

illumination energy is reflected from ortransmitted t"roug" ob0ects.

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Digital Image Processing

Applications Images depending on Source of energy:

9a0or sources of energy: lectromagnetic Spectrum

3coustic& ;ltrasonic lectronic

3rtificial sources < Computer generated images #Synt"etic images < used for modeling

)isualization

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DIP Applications 6amma /ay Imaging:

=uclear 9edicine

3stronomical Obser)ations

(ypical %amples: In0ect a patient wit" a radioacti)e isotope t"at

emits gamma rays as it decays. 6amma raydetectors capture t"e images

Positron mission (omograp"y $P('

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)"amples of gamma ra& imaging

*one $can P)T Image

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DIP Applications

7#ray Imaging:

9edical Diagonosis Industrial Inspections

3stronomy

(ypical %amples: 7#ray

3ngiograms < In0ecting 7#ray contrast medium

# n"ances t"e contrast of t"e blood )essels

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DIP Applications

Computerized 3%ial (omograp"y $C3(' ig"er energy 7#ray images < e%amining

circuit boards for flaws in manufacturing uman $>eads and faces& "ands& body& ...'

Industrial $Inspection& part pose estimation and

recognition& control&...' 5eisure and entertainment $museums& film industry&

p"otograp"y&...'

(raffic and transport $/oad& airport& seaport& license

identification& ...'

7 application $remote sensing& astronomy& biology&

sur)eillance& ...'

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3PP5IC3(IO=S

9edical $7rays& C(& 9/I& P(& ultrasound&

intensity& ...'

9ilitary $trac1ing& detection& ...' Police $firgerprints& sur)eillance& D=3 analysis&

biometry& ...'