Attempt at cubism

[afre (Alan)]

Would this help?

@afre

To work on a neighbourhood of pixels (N), I would do

foo_k : check ${1=1}>=1
  f "begin(const boundary=1; const S=$1*2+1);
    ref(crop(x-$1,y-$1,0,c,S,S,1,1),N)"

Then use N to do your calculations.