Topics in Digital Image Processing

A. Overview of Image Processing System

B. Applications of Digital Image Processing

1. Satellite Television
2. Magnetic Resonance Imaging
3. Computer Tomography
4. Geographical Information Systems
5. Astronomy

C.. What is an image ? What is a Digital Image ? What is Digital Image Processing ?

D. Elements of an image-processing system

1. Image Sampling
2. Quantisation
3. Processing
4. Storage
5. Display

 

E. What are the advantages and disadvantages of digital images ?

F. Digital Image Processing is the processing of an image by means of a computer . Advantageswith this    process are flexibility and adaptability , Data storage and transmission.

G. Image processing techniques include

1.  Image enhancement
2. Image restoration
3. Image fusion
4. Image watermarking 

H. How is a digital image represented ?

I. What do the following terms mean in DIP parlance ?

 

1. Neighbors of a pixel 
2. Adjacency
3. 2-adjacency and m-adjacency

 J. Sampling theory

1.  Image Sampling techniques and 2-D sampling (mathematical treatment)
2. Retrieving an image from its sample (mathematical treatment)

Problem: Suppose an image of dimension 4 x 6 inches has details to the frequency of 400 dots per inch in each direction. How many samples are required to preserve the information in the image ?

 

K. Quantisation : Representing the sampled data by a finite number of levels based on some criteria

 

1. Scalar quantization
1. Uniform quantiser : mid-tread vs mid-rise quantisers
2. Non-uniform quantiser : Lloyd-Max quantiser
2. Vector quantiser
3. Resolution : gives the degree of distinguishable details
1. Spatial resolution : smallest discernible detail in the image. Depends on number of pixels
2. Gray-level resolution : Smallest discernible change in the gray level. Depends on number of gray levels.

Question : What is false contouring ?

 

L. Human Visual System (HVS) – Anatomy :

1.  Explain with neat sketches , the anatomy of the eye and its functions. Know the functions of different parts of an eye such as : pupil, iris, Sclera, Cornea, Aqueous humor, Ciliary body, Conjunctive, Lens, Zonule fibers, Rectus tendon, One serrate, Choroid, Vitreous humor, Retina, Disc, Fovea, epithelium pigment, Lemina cribose, Macula lutca, optic nerve, Sheath, blind spot, rods and cones.
2. Vision : Photopic and Scotopic vision.
3. Brightness and Contrast. What is Simultaneous contrast ?
4. Laws of Physics associated with vision : Weber’s law, Steven’s law, Bloch’s law, Ricco’s law, Piper’s law.
5. What is Machband effect ?

 

M. Classification of Digital Images

1. Raster Image or Bitmap image
2. Vector image

 N. Image Types

1.  Binary Image
2. Grayscale image
3. Colour image
4. Volume image : Eg. CT Scan image : 
1. Question : What is a volume element in a Volume image called ?
5. Range image or depth image
6. Multispectral image

O. Elements of an image processing system :

1.  Image sensor and acquisition : 
1. CCD 
1. Function : Exposure, Charge transfer, Charge-to-voltage conversion and output amplification.
2. Format : Point scanning, Line scanning, Area Scanning
3. Architecture : Full-frame, Frame transfer
4. Advantage and disadvantages of CCD
2. CMOS image sensor : Function, Format and Architecture, dvantages and disadvantages.
3. Applications of CCD vs CMOS sensors
4. Comparison of CCD and CMOS image sensors on parameters like : Power consumption, System integration, Image Quality, Read-out mode, Fixed-pattern Noise, Dynamic range, Fill factor, cost.

 Terminology of an image-sensor : dark current, pixel, photo site, fill factor, quantum efficiency