1. Introduction to MATLAB’s Signal & Image Processing toolboxes

2. Overview What’s in the toolboxes Learn basic techniques to use them
Using MATLAB’s built in help and demos

3. Setup Log in to your machines Start MATLAB
Open a web browser and type in:

4. Basic of signal sampling
MATLAB stores signals in arrays – we are only storing samples
Nyquist theorem Fs >= 2 * fmax
But what is the sampling rate in MATLAB?

5. Signal processing Functions in MATLAB
conv
filter
fft
ifft

6. Time domain filters sinc FIR – windowing IIR – butterworth
fir1(n,Wn) returns row vector b containing the n+1 coefficients of an order n lowpass FIR filter with normalized cutoff frequency Wn
IIR – butterworth
butter(n,Wn) designs an order n lowpass digital Butterworth filter with normalized cutoff frequency Wn

7. Signal Processing Toolbox
FIR filter design:
fir1 – uses windowing
fir2 – uses idft
IIR filter design
butter – butterworth design
cheby1/2 – chebyshev design
yulewalker – recursive design
fdatool - GUI

8. Things to do.. Try filtering out the high pass component
Mix in a 3rd sinusoid, and make a bandpass filter
Look up ‘wavrecord’ and ‘wavplay’ in MATLAB help and see if you can find something interesting to do with it and these filters.

9. Questions for now?

10. Image Processing Toolbox
Loading an image
imread
Displaying an image
imshow
Saving to a file
imwrite

11. Color images – are made up of 3 color components, can’t be processed directly
rgb2gray – converts to a grayscale image
im2bw – converts to a black & white image
process each color plane individually

12. Spatial transforms
imrotate
imresize
imfilter
fspecial

13. Image registration & connected components
normxcorr2
bwlabel
imdilate
imerode
imclose
imopen

14. Image enhancement & restoration
imhist
histeq
medfilt2
wiener2

15. Accessing Demos Type ‘demos’ at the command line
In the left sidebar, select MATLAB toolboxes
Expand a toolbox, and then any subcategories

16. Questions