Hello Yohanes,
val = imread(' ... '); % Your input matrix/image
[xCoOrd, yCoOrd] = [ ... ] % Co-Ordinates of the center pixel
nbh = 5; % Neighborhood Size
For a square neighborhood, the variable roi will hold the intensity values of neighboring pixels.
limit = floor(nbh/2);
roi = val(xCoOrd-limit:xCoOrd+limit, yCoOrd-limit:yCoOrd+limit);
Additionally, if you want the positions of the neighbors in subscripts,
rowLen = [xCoOrd - limit: xCoOrd + limit]'; % Range of Rows
colLen = [yCoOrd - limit: yCoOrd + limit]; % Range of Columns
rowIdx = meshgrid(rowLen, 1:nbh)'; % All the X coordinates of neighbors
colIdx = meshgrid(colLen, 1:nbh); % All the Y coordinates of neighbors
Hope this helps!
