Deleting duplicate images in 3-dimesional matrix

Question

Dimitris M 2012-7-1

Hello

I have a quite simple question that I can not solve.

I have a stack of images in a matrix N x M x D. Is there a way to delete duplicated images may be included in this matrix easily ?

I have some complex for loop algorithm that I could try to implement but I was thinking they may be an easier way.

Thank you in advance

Answer 1

Teja Muppirala 2012-7-1

%First, I'll make some sample data with some duplicates:

A = rand(200,200,50);
A(:,:,16) = A(:,:,41);
A(:,:,32) = A(:,:,41);  
A(:,:,22) = A(:,:,29);

%Step 1. Convert the 3d matrix into a bunch of rows

sizeA = size(A);  
A_rows = reshape(A,[],sizeA(3))';

%Step 2. Call unique on the rows

A_unique = unique(A_rows,'stable','rows');

%Step 3. Reshape the rows back into a 3d matrix

A_unique = reshape( A_unique' ,sizeA(1),sizeA(2),[]);