Bsc Csit Nepal

Image Processing

Course Description:

This course covers the investigation, creation and manipulation of digital images by computer. The course consists of theoretical material introducing the mathematics of images and imaging. Topics include representation of two-dimensional data, time and frequency domain representations, filtering and enhancement, the Fourier transform, convolution, interpolation. The student will become familiar with Image Enhancement, Image Restoration, Image Compression, Morphological Image Processing, Image Segmentation, Representation and Description, and Object Recognition.

Course Objectives:

The objective of this course is to make students able to:

  • develop a theoretical foundation of Digital Image Processing concepts.
  • provide mathematical foundations for digital manipulation of images; image acquisition; preprocessing; segmentation; Fourier domain processing; and compression.
  • gain experience and practical techniques to write programs for digital manipulation of images; image acquisition; pre-processing; segmentation; Fourier domain processing; and compression.

Course Contents:

Unit 1: Introduction (5 Hrs.)

  • Digital Image, A Simple Image Model

    Definition of digital image, pixels, representation of digital image in spatial domain as well as in matrix form.

  • Fundamental steps in Image Processing

    Block diagram of fundamentals steps in digital image processing, application of digital image processing system, Elements of Digital Image Processing systems

  • Element of visual perception

    Structure of the Human, Image Formation in the Eye, Brightness Adaptation and Discrimination

  • Sampling and Quantization

    Basic Concepts in Sampling and Quantization, Representing Digital Images, Spatial and Gray- Level Resolution

  • Some basic relationships like Neighbors

    Neighbors of a Pixel, Adjacency, Connectivity, Regions, and Boundaries, Distance Measures between pixels

Unit 2: Image Enhancement and Filter in Spatial Domain (8 Hrs.)

  • Basic Gray Level Transformations

    Point operations, Contrast stretching, clipping and thresholding, digital negative, intensity level slicing, log transformation, power log transformation, bit plane slicing

  • Histogram Processing

    Unnormalized and Normalized Histogram, Histogram Equalization, Use of Histogram Statistics for Image Enhancement

  • Spatial operations

    Basics of Spatial Filtering, Linear filters, Spatial Low pass smoothing filters, Averaging, Weighted Averaging, Non-Linear filters, Median filter, Maximum and Minimum filters, High pass sharpening filters, High boost filter, high frequency emphasis filter, Gradient based filters, Robert Cross Gradient Operators, Prewitt filters, Sobel filters, Second Derivative filters, Laplacian filters

  • Magnification

    Magnification by replication and interpolation

Unit 3: Image Enhancement in the Frequency Domain (8 Hrs.)

  • Introduction

    Introduction to Fourier Transform and the frequency Domain, 1-D and 2-D Continuous Fourier transform, 1-D and 2-D Discrete Fourier transform

  • Properties of Fourier Transform

    Logarthmic, Separability, Translation, Periodicity, Implications of Periodicity and symmetry

  • Smoothing Frequency Domain Filters

    Ideal Low Pass Filter, Butterworth Low Pass Filter, Gaussian Low Pass Filter

  • Sharpening Frequency Domain Filters

    Ideal High Pass Filter, Butterworth High Pass Filter, Gaussian High Pass Filter, Laplacian Filter

  • Fast Fourier Transform

    Computing and Visualizing the 2D DFT (Time Complexity of DFT), Derivation of 1-D Fast Fourier Transform, Time Complexity of FFT, Concept of Convolution, Correlation and Padding.

  • Other Image Transforms

    Hadamard transform, Haar transform and Discrete Cosine transform

Unit 4: Image Restoration and Compression (8 Hrs.)

  • Image Restoration

    Introduction, Models for Image degradation and restoration process, Noise Models (Gaussian, Rayleigh, Erlang, Exponential, Uniform and Impulse), Estimation of Noise Parameters

  • Restoration Filters

    Mean Filters: Arithmetic, Geometric, Harmonic and Contraharmonic Mean Filters Order Statistics Filters: Median, Min and Max, Midpoint and Alpha trimmed mean filters Band pass and Band Reject filters: Ideal, Butterworth and Gaussian Band pass and Band Reject filters

  • Image Compression

    Introduction, Definition of Compression Ratio, Relative Data Redundancy, Average Length of Code Redundancies in Image: Coding Redundancy (Huffman Coding), Interpixel Redundancy (Run Length Coding) and Psychovisual Redundancy (4- bit Improved Gray Scale Coding: IGS Coding Scheme)

  • Image compression models:

    Lossless and Lossy Predictive Model (Block Diagram and Explanation)

Unit 5: Introduction to Morphological Image Processing (8 Hrs.)

  • Introduction

    Logic Operations involving binary images, Introduction to Morphological Image Processing, Definition of Fit and Hit

  • Morphological Operations

    Dilation and Erosion, Opening and Closing

Unit 6: Image Segmentation (8 Hrs.)

  • Introduction

    Definition, Similarity and Discontinuity based techniques

  • Discontinuity Based Techniques

    Point Detection, Line Detection, Edge Detection using Gradient and Laplacian Filters, Mexican Hat Filters, Edge Linking and Boundary Detection, Hough Transform

  • Similarity based techniques

    Thresholding: Global, Local and Adaptive Region Based Segmentation: Region Growing Algorithm, Region Split and Merge Algorithm

Unit 7: Representations, Description and Recognition (5 Hrs.)

  • Representation and Descriptions

    Introduction to some descriptors: Chain codes, Signatures, Shape Numbers, Fourier Descriptors

  • Recognition

    Patterns and pattern classes, Decision-Theoretic Methods, Introduction to Neural Networks and Neural Network based Image Recognition

  • Pattern Recognition

    Overview of Pattern Recognition with block diagram


Laboratory Work:

Students are required to develop programs in related topics using suitable programming languages such as MatLab or Python or other similar programming languages.


Text Books:

  1. Rafael C. Gonzalez and Richard E. Woods, “Digital Image Processing”, Pearson Edition, Latest Edition.

Reference Books:

  1. I. Pitas, “Digital Image Processing Algorithms”, Prentice Hall, Latest Edition.
  2. A. K. Jain, “Fundamental of Digital Image processing”, Prentice Hall of India Pvt. Ltd., Latest Edition.
  3. K. Castlemann, “Digital image processing”, Prentice Hall of India Pvt. Ltd., Latest Edition.
  4. P. Monique and M. Dekker, “Fundamentals of Pattern recognition”, Latest Edition.