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Digital Image Processing
Lecture 1(Introduction)
Bu-Ali Sina UniversityComputer Engineering Dep.
Fall 2011
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Introduction
One picture is worth more than ten thousandpwords
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Outline
Syllabus References Course Plane Grading and policies Introduction to image processing
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Introduction
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Syllabus
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MSRT References
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References
Digital Image Processing, Rafael C.Gonzalez & Richard E. Woods,Addison-Wesley, 2002
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Digital Image Processing Using matlabmuya
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Recommended journals and conferences
IEEE tran. On Image processingJournal of Graphics, Vision and Image Processing(GVIP)Image and Vision ComputingComputer Vision and Image UnderstandingJournal of Visual Communication and ImageRepresentationInternational Journal of Computer VisionMachine Vision and ApplicationsJournal of Mathematical Imaging and VisionGraphical Models and Image Processing
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Course planImage fundamentalImage enhancement (Spatial domain)Image transform (Fourier, DCT)Image enhancement (Frequency domain)Image restorationColor image processingImage compressionMorphological image processingImage segmentation
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Grading and PoliciesExams 50%
Midterm 50% (25% of total) about 15/8/90 Final 50% (25% of total)
Final Project (25%) One project (deadline is about 31/1/90)
Seminar (15%)Seminar (15%) Every body presents a seminar (select a subject until
15/8/90)Home works (10%)
5 home works
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Hours: 8-10 Sun. and Tue. (every two week)
Site: http://Profs.basu.ac.ir/khotanlou
Email:[email protected]@basu.ac.ir
Contact: 8257410, 11 (324 )
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ContentsThis 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 imageState of the art examples of digital image
processing
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What is a Digital Image?A digital image is a representation of a two-dimensional image as a finite set of digitalvalues, called picture elements or pixels
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What is a Digital Image? (contH)Pixel values typically represent gray levels,colours, heights, etcRemember digitization implies that a digitalimage is an approximation of a real scene
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1 pixel
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What is digital image?An image: 2-d function
I=f(x,y) I: intensity(or color) (x,y): coordinate When (x y) and I are finite and discrete quantitiesWhen (x,y) and I are finite and discrete quantities
-> digital image pixels, picture elements, image elements, pels
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Representing digital images
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Pixels
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Side story of Lena
1972 playboy: Miss Nov. 1997 Lena
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Representing digital images
Matrix form
f(0,0) f(0,1) f(0,N-1)f(1,0) f(0,1) f(1,N-1)
f(M-1,0) f(M-1,1) f(M-1,N-1)MxN
bits to store the image = M x N x kgray level = 2k
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Sources of digital images
Electromagnetic(EM) energyAcoustic imagingSynthetic (computer generated) imagingSynthetic (computer-generated) imaging
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EM images (cont.)The same objects in different EM spectrum
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Ultrasound images
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Synthetic images
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What is a Digital Image? (contH)Common image formats include:
1 sample per point (B&W or Grayscale) 3 samples per point (Red, Green, and Blue) 4 samples per point (Red, Green, Blue, and
Alpha, Opacity)
For most of this course we will focus on grey-scale images
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What is Digital Image Processing?Digital image processing focuses on two majortasks
Improvement of pictorial information for humaninterpretation
Processing of image data for storage,g g gtransmission and representation for autonomousmachine perception
Some argument about where image processingends and fields such as image analysis andcomputer vision start
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What is DIP? (contH)The continuum from image processing tocomputer vision can be broken up into low-,mid- and high-level processes
Low Level Process Mid Level Process High Level ProcessLow Level ProcessInput: ImageOutput: Image
Examples: Noiseremoval, imagesharpening
Mid Level ProcessInput: ImageOutput: Attributes
Examples: Objectrecognition,segmentation
High Level ProcessInput: AttributesOutput: Understanding
Examples: Sceneunderstanding,autonomous navigation
In this course we willstop here
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Research fields
Low-level processing
ImageEarly vision
Mid-level processing
High-level processing
processing
Computervision
Early vision
Brain processing
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Related fields
Image processing Inputs and outputs are images Extract attributes from images
Image analysisComputer vision
Use computers to emulate human vision Related to artificial intelligence (AI)
Pattern Recognition
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History of Digital Image ProcessingEarly 1920s: One of the first applications ofdigital imaging was in the news-paper industry
The Bartlane cable picturetransmission serviceIma
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Images were transferred by submarine cablebetween London and New York
Pictures were coded for cable transfer andreconstructed at the receiving end on atelegraph printer
Early digital image
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History of DIP (contH)Mid to late 1920s: Improvements to theBartlane system resulted in higher qualityimages
New reproductionprocesses basedIma
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on photographictechniques
Increased numberof tones inreproduced images Improved
digital image Early 15 tone digitalimage
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History of DIP (contH)1960s: Improvements in computing technologyand the onset of the space race led to a surgeof work in digital image processing
1964: Computers used toimprove the quality ofIma
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images of the moon takenby the Ranger 7 probe
Such techniques were usedin other space missionsincluding the Apollo landings
A picture of the moon takenby the Ranger 7 probeminutes before landing
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History of DIP (contH)1970s: Digital image processing begins to beused in medical applications
1979: Sir Godfrey N.Hounsfield & Prof. Allan M.Cormack share the Nobel
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Prize in medicine for theinvention of tomography,the technology behindComputerised AxialTomography (CAT) scans Typical head slice CAT
image
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History of DIP (contH)1980s - Today: The use of digital imageprocessing techniques has exploded and theyare now used for all kinds of tasks in all kindsof areas
Image enhancement/restorationg Artistic effects Medical visualisation Industrial inspection Law enforcement Human computer interfaces
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Examples: Image EnhancementOne of the most common uses of DIPtechniques: improve quality, remove noise etc
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Examples: The Hubble TelescopeLaunched in 1990 the Hubbletelescope can take images ofvery distant objectsHowever, an incorrect mirrormade many of Hubblesmade many of Hubble simages uselessImage processingtechniques wereused to fix this
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Examples: Artistic EffectsArtistic effects areused to makeimages more visuallyappealing, to addspecial effects and topmake compositeimages
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Examples: MedicineTake slice from MRI scan of canine heart, andfind boundaries between types of tissue
Image with gray levels representing tissuedensity
Use a suitable filter to highlight edgesImage
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g g g
Original MRI Image of a Dog Heart Edge Detection ImageImag
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Examples: GISGeographic Information Systems
Digital image processing techniques are usedextensively to manipulate satellite imagery
Terrain classification MeteorologyIma
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Examples: GIS (contH)Night-Time Lights of theWorld data set
Global inventory ofhuman settlement
Not hard to imagineImage
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gthe kind of analysisthat might be doneusing this data
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Examples: Industrial InspectionHuman operators areexpensive, slow andunreliableMake machines do thejob insteadIma
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job insteadIndustrial vision systemsare used in all kinds ofindustriesCan we trust them?
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Examples: PCB InspectionPrinted Circuit Board (PCB) inspection
Machine inspection is used to determine that allcomponents are present and that all solder jointsare acceptable
Both conventional imaging and x-ray imagingare used
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Examples: Law EnforcementImage processingtechniques are usedextensively by lawenforcers
Number plateImage
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precognition for speedcameras/automated tollsystems
Fingerprint recognition Enhancement of CCTV
images
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Examples: HCI
Try to make human computerinterfaces more natural
Face recognition Gesture recognition
Does anyone remember theuser interface from MinorityReport?These tasks can beextremely difficult
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Key Stages in Digital Image Processing
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancement
ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Image Aquisition
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Image Enhancement
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Image Restoration
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Morphological Processing
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Segmentation
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Object Recognition
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
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Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Representation & Description
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancementImag
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ImageAcquisition
g
Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Image Compression
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancement
ImageAcquisition
g
Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Key Stages in Digital Image Processing:Colour Image Processing
ImageRestoration
MorphologicalProcessing
SegmentationImageEnhancement
ImageAcquisition
g
Representation& Description
Enhancement
ObjectRecognition
Problem Domain
Colour ImageProcessing
ImageCompression
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Fundamental steps in DIP
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SummaryWe have looked at:
What is a digital image? What is digital image processing? History of digital image processing State of the art examples of digital imageState of the art examples of digital image
processing Key stages in digital image processing