Introduction to Digital Image Processing

1
Introduction to Digital Image Processing
March 4, 2003

• Shreekanth Mandayam
• ECE Department
• Rowan University
• http//engineering.rowan.edu/shreek/spring03/cc/

2
Module Overview

• Lecture 1
• Digital Image Fundamentals
• Lecture 2
• Digital Image Enhancement
• Digital Image Segmentation
• Digital Image Compression

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Lecture 1

• Digital Image Fundamentals

4
Monochromatic Digital Image
y
x
Gray Level
f(x,y)
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(No Transcript)
6
Sampling Quantization

• Sampling
• demos/demo1sampling_and_quantization/demo_sampling
  .m
• Quantization
• demos/demo1sampling_and_quantization/demo_quant.m

Digital Image Processing Course Nos. 0909-452-01
(Senior Elective) and 0909-552-01 (Graduate)
Fall 2003 Previous Offering http//engineering.
rowan.edu/shreek/fall01/dip/
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Fundamental Steps
Preprocessing (Enhancement Restoration)
Representation Description
Segmentation
Knowledge Base
Problem Domain
Image Acquisition
Recognition Interpretation
Result
Rafael C. Gonzalez and Richard E. Woods, Digital
Image Processing, Addison-Wesley, 1992
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Digital Image Enhancement
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Point Processing(Intensity Transformation)
s(x,y) T r(x,y)
Transformed Gray Level
Original Gray Level
Transformation Function
gtgtimadjdemo gtgtimadjust
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Point Processing

• Pixel Operations
• Point processing
• Histogram equalization
• Connectivity

individual pixels
all pixels
neighboring pixels
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Point Processing
L-1
s2
s
g
s
s1
0
r
r
r1
r2
L-1
0
gtgtimadjdemo gtgtimadjust
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Image Histogram
gtgtimadjdemo gtgtimhist
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Histogram Equalization(Balancing)
gtgtimadjdemo gtgthisteq
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Fundamental Steps
Preprocessing (Enhancement Restoration)
Representation Description
Segmentation
Knowledge Base
Problem Domain
Image Acquisition
Recognition Interpretation
Result
Rafael C. Gonzalez and Richard E. Woods, Digital
Image Processing, Addison-Wesley, 1992
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Digital Image Segmentation
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Spatial Filtering (Masking)
Portion of a digital image
Mask
Replace with
R
w1z1 w2z2 .. w9z9
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Edge Detection
Sobel Masks
gtgtedgedemo gtgtedge
demos/demo2spatial_filtering/edgegradientdemo.m
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Fundamental Steps
Preprocessing (Enhancement Restoration)
Representation Description
Segmentation
Knowledge Base
Problem Domain
Image Acquisition
Recognition Interpretation
Result
Rafael C. Gonzalez and Richard E. Woods, Digital
Image Processing, Addison-Wesley, 1992
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Digital Image Compression
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Discrete Cosine Transform

• Discrete Cosine Transform

• Information Concentration
• Data Compaction
• Feature Extraction

gtgtdctdemo
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JPEG Compression Standard
Compute DCT F(u,v)
Reorder to form 1-D Sequence
Level Shift
f(x,y)
Normalize
Compute DC Coefficient
Compute AC Coefficients
http//www.jpeg.org/
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Summary
Digital Image Processing Course Nos. 0909-452-01
(Senior Elective) and 0909-552-01 (Graduate)
Fall 2003 Previous Offering http//engineering.
rowan.edu/shreek/fall01/dip/