It looks like you're new here. If you want to get involved, click one of these buttons!

- 141.8K All Categories
- 104.8K Programming Languages
- 6.4K Assembler Developer
- 1.9K Basic
- 39.9K C and C++
- 4.3K C#
- 7.9K Delphi and Kylix
- 4 Haskell
- 9.6K Java
- 4.1K Pascal
- 1.3K Perl
- 2K PHP
- 523 Python
- 37 Ruby
- 4.3K VB.NET
- 1.6K VBA
- 20.8K Visual Basic
- 2.6K Game programming
- 312 Console programming
- 89 DirectX Game dev
- 1 Minecraft
- 110 Newbie Game Programmers
- 2 Oculus Rift
- 8.9K Applications
- 1.8K Computer Graphics
- 732 Computer Hardware
- 3.5K Database & SQL
- 525 Electronics development
- 1.6K Matlab
- 628 Sound & Music
- 257 XML Development
- 3.3K Classifieds
- 198 Co-operative Projects
- 189 For sale
- 189 FreeLance Software City
- 1.9K Jobs Available
- 601 Jobs Wanted
- 201 Wanted
- 2.9K Microsoft .NET
- 1.7K ASP.NET
- 1.1K .NET General
- 3.3K Miscellaneous
- 5 Join the Team
- 0 User Profiles
- 353 Comments on this site
- 62 Computer Emulators
- 2.1K General programming
- 187 New programming languages
- 612 Off topic board
- 177 Mobile & Wireless
- 51 Android
- 124 Palm Pilot
- 335 Multimedia
- 151 Demo programming
- 184 MP3 programming
- 0 Bash scripts
- 22 Cloud Computing
- 53 FreeBSD
- 1.7K LINUX programming
- 368 MS-DOS
- 0 Shell scripting
- 320 Windows CE & Pocket PC
- 4.1K Windows programming
- 906 Software Development
- 408 Algorithms
- 68 Object Orientation
- 89 Project Management
- 90 Quality & Testing
- 250 Security
- 7.6K WEB-Development
- 1.8K Active Server Pages
- 61 AJAX
- 2 Bootstrap Themes
- 55 CGI Development
- 19 ColdFusion
- 224 Flash development
- 1.4K HTML & WEB-Design
- 1.4K Internet Development
- 2.2K JavaScript
- 35 JQuery
- 290 WEB Servers
- 152 WEB-Services / SOAP

mingwersen
Member Posts: **1**

in Matlab

Need major help on an assignment. ANy help would be nice. I have a image compression bonus assignment as follows

"1. Download the image.mat file from blackboard and load this into matlab. Do this by

typing "load image.mat" in the command prompt. There should now be the variable

A in your workspace. A has 3 dimensions. The rst two are the height and width

of the image, the last dimension is of length 3. This is because images have 3 color

planes.

2. View the image with the command "image(A)"

3. Turn A into a matrix of doubles with the command "double(A)".

4. Since each color plane can be considered a square matrix, we can perform an eigenvalue

decomposition to each plane. Do this with the function "eig(A)".

5. Try sorting the eigenvalues of each plane by magnitude (absolute value of the values).

Approximate each bit plane by only using the 100 most in

uential eigenvalues and

eigenvectors. Repeat this for 50, 25, 10, and 5. Reconstruct all 3 color planes with

each approximation. Name the reconstruction B.

6. There are likely to be imaginary values in B. Get rid of these with the command

"real(B)". Round the values of B into integers with "round(B)". Turn B into a matrix

of uint8's with "uint8(B)". View all the images. How good is the approximation? Plot

the mean squared error between A and B as a function of the number of eigenvalues

you keep.

7. Repeat steps 5 and 6 by using the eigenvalues of smallest magnitude."

I have been able to import the image, make it doubles, then i seperated it into 3 matrices so i could apply eig() onto it. thats where im lost.

"1. Download the image.mat file from blackboard and load this into matlab. Do this by

typing "load image.mat" in the command prompt. There should now be the variable

A in your workspace. A has 3 dimensions. The rst two are the height and width

of the image, the last dimension is of length 3. This is because images have 3 color

planes.

2. View the image with the command "image(A)"

3. Turn A into a matrix of doubles with the command "double(A)".

4. Since each color plane can be considered a square matrix, we can perform an eigenvalue

decomposition to each plane. Do this with the function "eig(A)".

5. Try sorting the eigenvalues of each plane by magnitude (absolute value of the values).

Approximate each bit plane by only using the 100 most in

uential eigenvalues and

eigenvectors. Repeat this for 50, 25, 10, and 5. Reconstruct all 3 color planes with

each approximation. Name the reconstruction B.

6. There are likely to be imaginary values in B. Get rid of these with the command

"real(B)". Round the values of B into integers with "round(B)". Turn B into a matrix

of uint8's with "uint8(B)". View all the images. How good is the approximation? Plot

the mean squared error between A and B as a function of the number of eigenvalues

you keep.

7. Repeat steps 5 and 6 by using the eigenvalues of smallest magnitude."

I have been able to import the image, make it doubles, then i seperated it into 3 matrices so i could apply eig() onto it. thats where im lost.

Terms of use / Privacy statement / Publisher: Lars Hagelin

Programmers Heaven articles / Programmers Heaven files / Programmers Heaven uploaded content / Programmers Heaven C Sharp ebook / Operated by CommunityHeaven LLC

© 1997-2015 Programmersheaven.com - All rights reserved.