IIB: 4F8 Image Processing: 2015-16, Lent Term.

Image Processing

Handout 01-- The 2D Fourier Transform etc

Sinusoid_Demo.m -- illustrates the 2d FT of a 2d sinusoid. As expected, the FT contains just 4 peaks at + and - the 2 frequencies.
lenna256.mat -- mat file containing the 256x256 image of lenna in the array x.
grayimage.m -- small program to display grayscale images as used by other programs
convolution_demo.m -- program to convolve Lenna with a gaussian to illustrate blurring

Handout 2 -- Digitisation, sampling and the 2d-DFT

For an example of aliasing to produce moire patterns see http://ptolemy.eecs.berkeley.edu/eecs20/week13/moire.html
Brick Wall image for use in the example sheet moireB.jpg
Quantiser_demo.m : program to quantise Lenna to a specified number of bits

Handout 3 -- 2D Digital Filters

imagephasedemo2.m : program to illustrate importance of phase in images by giving amplitude and phase only reconstructions
imagefilter3_demo.m : filtering of Lenna with three bandpass filters (2 rectangular and one circularly symmetric)
runbessel.m : program to illustrate the form of the IFT of the ideal circularly symmetric bandpass filter for different upper and lower frequencies.

Handout 4 -- 2D Digital filter design and windowing

productwindow.m : program to plot the 2d windows formed from the product of 1d windows and their spectra [rectangular, Hamming and Kaiser]
ProdWindowCircBP.m : program to investigate the effects of windowing, with product window functions [rectangular, Hamming and Kaiser], an ideal circularly symmetric lowpass or bandpass filter. Also show what the effects of such a filter are on Lenna.
RotatedWindow.m : program to plot the 2d windows and their spectra formed from the rotation of 1d windows [rectangular, Hamming and Kaiser].
RotWindowCircBP.m : program to investigate the effects of windowing, with rotated window functions [rectangular, Hamming and Kaiser], an ideal circularly symmetric lowpass or bandpass filter. Also show what the effects of such a filter are on Lenna.

Handout 5 -- Image Deconvolution

Handout 6 -- Deconvolution and image enhancement

Examples Paper and Solutions :

Tripos Papers and Cribs for 2007 to 2010 can be found here

Quick Links: Home; History; Members; Research; Events and Seminars; Postgraduate Applications; Vacancies; Contact Us

Signal Processing and Communications Laboratory