09-10-2012, 12:06 PM
Image Processing - Introduction and Application
Image Processing.ppt (Size: 4.57 MB / Downloads: 683)
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(i D, j D) }
The image can now be represented as a matrix of integer values
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.
Companies In this Field In India and came to IITK
Sarnoff Corporation
Kritikal Solutions
National Instruments
GE Laboratories
Ittiam, Bangalore
Interra Systems, Noida
Yahoo India (Multimedia Searching)
nVidia Graphics, Pune (have high requirements)
ADE Bangalore, DRDO