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decimation in dwt is

Asked by beenu singh

beenu singh (view profile)

on 17 Jun 2013

i am performing following operation on 256*256 lena image after execution four bands are of size 136*136 according to me it should be of 128*128 pls clear.

[Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('db9'); [LLD,LHD,HLD,HHD]=dwt2(GRAY,Lo_D,Hi_D);

1 Comment

It seems like wfilters and dwt2 are not MATLAB toolbox functions. Maybe, you are using a window inside of these functions. If you provide a better insight into the code, the inconsistency can be explained.

beenu singh

beenu singh (view profile)

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1 Answer

Answer by Wayne King

Wayne King (view profile)

on 17 Jun 2013

The problem is that you should first set the dwtmode to 'per' to get the subband sizes you expect.

   dwtmode('per');
   load woman; % 256x256
   [Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('db9'); 
   [LLD,LHD,HLD,HHD]=dwt2(X,Lo_D,Hi_D);

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Wayne King

Wayne King (view profile)

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