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This lecture covers the basics of image processing, including image formation, Fourier Transform theory, color manipulation, and more. Learn about digital image representation and processing operations.
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Activity 2: Peer Assessment ActivityIIT Bombay FDP101x : October 2018 by VIJAYARANI R
Image Processing Lecture 1 Introduction and Application by VIJAYARANI R
Course Structure • Introduction to Image Processing, Application and Prospects (Today) • Introduction, Image formation, camera models and perspective geometry • Fourier Transform theory , Convolution and Correlation • Color, Image enhancement Techniques • Binary images: thresholding, moments, topology
Concepts Covered Need for Image Processing • Human Perception • Filtering • Image Enhancement • Image deblurring
Image Formation f(x,y) = reflectance(x,y) * illumination(x,y) Reflectance in [0,1], illumination in [0,inf]
What is an image? • We can think of an image as a function, f, from R2 to R: • f( x, y ) gives the intensity at position ( x, y ) • Realistically, we expect the image only to be defined over a rectangle, with a finite range: • f: [a,b]x[c,d] [0,1] • A color image is just three functions pasted together. We can write this as a “vector-valued” function:
What is a digital image? • We usually operate on digital (discrete)images: • Sample the 2D space on a regular grid • Quantize each sample (round to nearest integer) • If our samples are D apart, we can write this as: f[i ,j] = Quantize{ f(iD, jD) } • The image can now be represented as a matrix of integer values
Image processing • An image processing operation typically defines a new image g in terms of an existing image f. • We can transform either the range of f. • Or the domain of f: • What kinds of operations can each perform?
Neighborhood Processing (filtering) • Q: What happens if I reshuffle all pixels within the image? • A: It’s histogram won’t change. No point processing will be affected… • Need spatial information to capture this.
Reflection Spot: Why do we need image Processing? It is motivated by two major application • Improvement of pictorial information for human perception • Image processing for autonomous machine application • Efficient storage and transmission
LbD1 Q1. What effect is caused by under sampling? a)Summation b) Smoothing c) Sharpening d) Aliasing Ans.d) aliasing
LbD1 Q2. In frequency domain, what is the equivalent operation of product of two functions in spatial domain. a) Correlation b) Convolution c) Fourier transform d) Fast Fourier transform Ans.b) Convolution
Feedback • In this video and PPT is very useful? a) yes b) No