MATLAB

Matlab

Table of Contents

Introduction3

What is matlab3

How Do I Need To Use matlab5

Image Processing and How Many Types8

Spatial Domain There Are 5 Functions10

Image Negative And Log Transformation13

Coding16

Photographic Negative17

Gamma Transformations18

Logarithmic Transformations21

Contrast-Stretching Transformations26

The intrans and changeclass Functions31

Spatial Filtering32

Basic Idea33

Gantt Chart39

Conclusion39

Matlab

Introduction

MATLAB is an interactive program for numerical computation and data visualization; it is used extensively by control engineers for analysis and design. There are many different toolboxes available which extend the basic functions of MATLAB into different application areas; in these tutorials, we will make extensive use of the Control Systems Toolbox. MATLAB is supported on Unix, Macintosh, and Windows environments; a student version of MATLAB is available for personal computers (Gilat, 2010, pp. 151-156). The codes learnt for using the MATLAB and the grey scale picture coding 256*256 is present in appendix section.

What is matlab

Matlab is a commercial "Matrix Laboratory" package which operates as an interactive programming environment. It is a mainstay of the Mathematics Department software lineup and is also available for PC's and Macintoshes and may be found on the CIRCA VAXes. Matlab is well adapted to numerical experiments since the underlying algorithms for Matlab's builtin functions and supplied m-files are based on the standard libraries LINPACK and EISPACK.

Matlab program and script files always have filenames ending with ".m"; the programming language is exceptionally straightforward since almost every data object is assumed to be an array. Graphical output is available to supplement numerical results.

Online help is available from the Matlab prompt (a double arrow), both generally (listing all available commands):

>> help

[a long list of help topics follows]

and for specific commands:

>> help fft

[a help message on the fft function follows].

Paper documentation is on the document shelf in compact black books and locally generated tutorials are available and are used in courses.

The answer to the most popular question concerning any program is this: leave a Matlab session by typing

quit

or by typing

exit

to the Matlab prompt.

The capabilities of Matlab can be extended through programs written in its own programming language. It provides the standard constructs, such as loops and conditionals; these constructs can be used interactively to reduce the tedium of repetitive tasks, or collected in programs stored in ``m-files'' (nothing more than a text file with extension ``.m''). I will first discuss the programming mechanisms and then explain how to write programs.

How Do I Need To Use matlab

Matlab is most often used interactively, but "batch" or "background" jobs can be performed as well. Debug your commands interactively and store them in a file (`script.m', for example). To start a background session from your input file and to put the output and error messages into another file (`script.out', for example), enter this line at the system prompt:

nice matlab < script.m >& script.out &

You can then do other work at the machine or logout while Matlab grinds out your program. Here's an explanation of the sequence of commands above.

The "nice" command lowers matlab's priority so that interactive users have first crack at the CPU. You must do this for noninteractive Matlab sessions because of the load that number--crunching puts on the ...