Computer Science and Engineering

Comprehensive Examination in Digital Image Processing

January, 2005, Professor Carl G. Looney

Based on CS 674 Digital Image Processing

Examination Conditions: 3 hour written exam., closed book, with one letter size sheet of paper with notes on front and back sides allowed for organization of material for quick retrieval (highly recommended).

Emphasized Topics

    Grayscale Images

            - thresholding images

            - analysis of image histogram for corrective action

            - adjust average gray level and variance of image to those desired

            - unsharp masking convolution masks

            - sharpening with hedged Laplacian masks

            - edge detection

            - spatial filtering with Matlab and user inputs

            - line thinning theory and Matlab application

            - fusing images via adding, subtracting, multiplying frames, blanking background, etc.

            - motion detection

            - eroding, dilating, segmenting using these, thresholding, with Matlab

            - boundarizing, boundarize with Matlab

            - watershed segmentation using Matlab

            - nearest neighbor and bilinear interpolation

            - affine transformations, zooming

            - affine transformation and zooming using Matlab

            - take fast Fourier transforms of images using Matlab

            - design highpass, bandpass, lowpass Gaussian and Butterworth in frequency domain

            - use Matlab to do frequency filter and return to spatial domain with scaling

            - zero padding with Matlab to make MxN image into RxR image, R = max{M,N}

    Color Images

            - RGB and HSI color models

            - Matlab conversion between RGB, HSV and YIQ color systems

            - separation of H, S and V in Matlab

            - types of processing of color images

            - sharpening, warming, cooling, decreasing/increasing color purity

            - using Matlab for these types of color processing

    Image File Formats

            - what is JPEG best for and why?

            - when to use GIF, PNG or TIF

            - PBM, PGM, PPM, detecting these file formats

            - reading/writing PBM, PGM, PPM file formats

            - RLE compression (PCX, BMP, TIF), know what it is, basically