CMPT 770 Homework #1


September 29,2000
Jennifer de Kleine
ID# 20003-7060

Here are the images produced by my work on assignment #1. Note that the images are slightly distorted because I specified each image (in HTML) to be a 100x100 square. Not all of the images were actually square-shaped.


1. Take a 2D square and compute it's Fourier transform

>> colormap("default")       # use the default 3*64 colormap
>> x=zeros(10);              # make a 10*10 matrix of zeros
>> x(30:80,30:80)=ones(51);  # change a square in the middle to ones
>> x = x*64;                 # change the ones to 64s (because the value is a colormap index)
>> imshow(x)                 # display the 2D square

>> y = fft(x) # compute it's Fourier transform >> z = abs(y) # compute the magnitude component >> imshow(z) # visualize the magnitude response

>> z = arg(y) # compute the phase component >> imshow(z) # visualize the phase response

2. Rotate the square by 45 degrees and compute it's Fourier transform

???

3. Take a picture and compute it's Fourier Transform

>> x = loadimage("baby.img") # load the image into variable 'x'
>> imshow(x)                 # display the image

>> y = fft(x) # compute the image's Fourier transform and store # the result in variable 'y' >> z = abs(y) # get the magnitude component and store it in 'z' >> imshow(z) # visualize the magnitude response

>> z = arg(y) # get the phase component and store it in 'z' >> imshow(y) # visulaize the phase response