Introduction
MATLAB stands for MATrix LABoratory and the software is built up around vectors and matrices.
It is a technical computing environment for high performance numeric computation and visualization.
It integrates numerical analysis, matrix computation, signal processing and graphics in an easy-to-
use environment, where problems and solutions are expressed just as they are written mathematically,
without traditional programming. MATLAB is an interactive system whose basic data element is a
matrix that does not require dimensioning. It enables us to solve many numerical problems in a
fraction of the time that it would take to write a program and execute in a language such as FORTRAN,
BASIC, or C. It also features a family of application specific solutions, called toolboxes. Areas in which
toolboxes are available include signal processing, image processing, control systems design, dynamic
systems simulation, systems identification, neural networks, wavelength communication and others.
It can handle linear, non- linear, continuous-time, discrete- time, multivariable and multirate systems.
How to start MATLAB
Choose the submenu "Programs" from the "Start" menu. From the "Programs" menu, open the
"MATLAB" submenu. From the "MATLAB" submenu, choose "MATLAB".
Procedure
1. Open Matlab.
2. File New Script.
3. Type the program in untitled window
4. File Save type filename.m in Matlab workspace path.
5. Debug Run.
6. Output will be displayed at Figure dialog box.
Library Functions clc:
Clear command window
Clears the command window and homes the cursor.
clear all:
Removes all variables from the workspace.
close all:
Closes all the open figure windows.
exp:
Y = exp(X) returns the exponential ex for each element in array X.
linespace:
y = linspace(x1,x2) returns a row vector of 100 evenly spaced points between x1 and x2.
rand:
X = rand returns a single uniformly distributed random number in the interval (0,1).
ones:
X = ones(n) returns an n-by-n matrix of ones.
zeros:
X = zeros(n) returns an n-by-n matrix of zeros.
plot:
plot(X,Y) creates a 2-D line plot of the data in Y versus the corresponding values in X.
subplot:
subplot(m,n,p) divides the current figure into an m-by-n grid and creates an axes for a subplot in the
position specified by p.
stem:
stem(Y) plots the data sequence, Y, as stems that extend from a baseline along the x-axis. The
data values are indicated by circles terminating each stem.
title:
title(str) adds the title consisting of a string, str, at the top and in the center of the current axes.
xlabel:
xlabel(str) labels the x-axis of the current axes with the text specified by str.
ylabel:
ylabel(str) labels the y-axis of the current axes with the string, str.
A Summary of MATLAB Commands Used
imread Read image from graphics file
imwrite Write image to graphics file
imfinfo Information about graphics file
imshow Display image
implay Play movies, videos, or image sequences
gray2ind Convert grayscale or binary image to indexed image
ind2gray Convert indexed image to grayscale image
mat2gray Convert matrix to grayscale image
rgb2gray Convert RGB image or colormap to grayscale
imbinarize Binarize image by thresholding
adapthresh Adaptive image threshold using local first-order statistics
otsuthresh Global histogram threshold using Otsu's method
im2uint16 Convert image to 16-bit unsigned integers
im2uint8 Convert image to 8-bit unsigned integers
imcrop Crop image
imresize Resize image
imrotate Rotate image
imadjust Adjust image intensity values or colormap
imcontrast Adjust Contrast tool
imsharpen Sharpen image using unsharp masking
histeq Enhance contrast using histogram equalization
adapthisteq Contrast-limited adaptive histogram equalization (CLAHE)
imhistmatch Adjust histogram of image to match N-bin histogram of reference image
imnoise Add noise to image
imfilter N-D filtering of multidimensional images
fspecial Create predefined 2-D filter
weiner2 2-D adaptive noise-removal filtering
medfilt2 2-D median filtering
ordfilt2 2-D order-statistic filtering
imfill Fill image regions and holes
imclose Morphologically close image
imdilate Dilate image
imerode Erode image
imopen Morphologically open image
imreconstruct Morphological reconstruction
watershed Watershed transform
dct2 2-D discrete cosine transform
hough Hough transform
graydist Gray-weighted distance transform of grayscale image
fft2 2-D fast Fourier transform
ifftshift Inverse FFT shift
imcomplement Complement image
immultiply Multiply two images or multiply image by constant
imsubtract Subtract one image from another or subtract constant from image
imdivide Divide one image into another or divide image by constant
imadd Add two images or add constant to image
