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Displaying the image of wavedec2

Asked by FIR

FIR (view profile)

on 24 Dec 2012
Latest activity Answered by Regan Dhakshnamurthy on 30 Jan 2014

I have code

 X=imread('cameraman.tif')

[C,S] = wavedec2(X,2,'haar');

for 2 level decomposition please tell how to display image in a single window,subplot must not be used

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FIR

FIR (view profile)

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4 Answers

Answer by Walter Roberson

Walter Roberson (view profile)

on 24 Dec 2012

Have you read the documentation for image() recently ?

2 Comments

FIR

FIR (view profile)

on 24 Dec 2012

yes image(C)or S is giving a straight line

Walter Roberson

Walter Roberson (view profile)

on 24 Dec 2012

You indicated that you must display the images in a single window and that subplot must not be used. There is a way to position images in an axes; examine the possible input arguments for image() for details.

Walter Roberson

Walter Roberson (view profile)

Answer by Wayne King

Wayne King (view profile)

on 24 Dec 2012
Edited by Wayne King

Wayne King (view profile)

on 24 Dec 2012

You have to select the particular coefficients you want from the wavedec2 output vector. You can use detcoef2 for that.

For example, to view the diagonal details, HH, at level two

    X = imread('cameraman.tif');
    [C,S] = wavedec2(X,2,'haar');
    [H,V,D] = detcoef2('all',C,S,2);
    imagesc(D); colormap gray

appcoef2() gives you the scaling coefficients

1 Comment

FIR

FIR (view profile)

on 24 Dec 2012

i need as like

http://imgur.com/SdyqC

Wayne King

Wayne King (view profile)

Answer by Wayne King

Wayne King (view profile)

on 24 Dec 2012

Then you can simply do:

     X = imread('cameraman.tif');
    [C,S] = wavedec2(X,2,'haar');
    A2 = appcoef2(C,S,'haar',2);
    [H1,V1,D1] = detcoef2('all',C,S,1);
    [H2,V2,D2] = detcoef2('all',C,S,2);

Now you have all the images in your plot.

    imagesc(A2); colormap gray;

gives you the image in the upper left corner and you have the 6 detail images. H1,V1,and D1 for level 1 and H2,V2, and D2 for level 2.

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Wayne King

Wayne King (view profile)

Answer by Regan Dhakshnamurthy on 30 Jan 2014

Hi Sir,

I want to see the four bands LL, LH, HL and HH separately after wavedec2(), How can i do this?

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