I've got a specific question and a related more general one... Why does imextendedmax() not give for example 9 in A(3,3) as a max? Generally... what is the best way for finding multiple maxes/peaks? The nice thing about imextended max is it allows a threshold where presumably everything under that threshold is not counted whereas imregionalmax and findpeaks are more general, less effective. A=round(rand(5)*10) A = 1 5 4 8 3 5 1 8 8 3 9 3 9 1 2 9 7 3 5 9 6 3 5 6 8 B=imextendedmax(A,8) B = 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1