Houghpeaks function in Hough transform ( matlab code ) -

look @ houghpeaks function hough transform in matlab toolbox:

peaks = houghpeaks(h, numpeaks)

peaks = houghpeaks(..., param1, val1,param2, val2)

paramter:

'nhoodsize' : two-element vector of positive odd integers: [m n].

question: nhoodsize must odd? why?

wouldn't because otherwise you're not landing on cell boundary?

1 2 3 4 5 6 7 8 9 

vs.

1 2 3 4 

in nhood calculations element in middle being evaluated , somehow being influenced surrounding values.