How can I find 26 neighbors of point with coordinates of (i,j,k)?

Yes sir.I am having indexes of voxel and its neighbours,so totally i will have 27 scalar values.Now leaving the actual voxel consider only the neighbours(26) and identify its neighbouring voxel values.How to perform this?

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Answer 2

KSSV 2016-11-3

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Answer 3

Walter Roberson 2017-3-15

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编辑：Walter Roberson 2017-3-15

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function [idx3d, valid, linidx] = neighbour26(i, j, k, Your3DMatrix)
  %returns the indices of the 26 3-D neighbors of location i, j, k within Your3DMatrix
  %In the first output, indices are returned as a 26 x 3 matrix of row, column, page triples.
  %Since on the border areas neighbours might be outside of the matrix, the
  %second output is a vector indicating which of the rows are valid.
  %The third output is the linear indices -- useful for extracting content
    [rows, cols, pages] = size(Your3DMatrix);
    [R, C, P] = ndgrid(R-1:R+1, C-1:C+1, P-1:P+1);
    idx3d = [R(:), C(:), P(:)];
    idx3d(14,:) = [];     %remove center
    valid = idx(:,1) >= 1 & idx(:,2) >= 1 & idx(:,3) >= 1 & idx(:,1) <= rows & idx(:,2) <= cols & idx(:,3) <= pages;
    linidx = nan(size(valid));
    linidx(valid) = sub2ind( [rows, cols, pages], idx3(valid,1), idx3d(valid,2), idx3d(valid,3) );