cv4

cv4.py

import itertools

image = [[10,10,10,10,10,10,10,10,10],
         [10,10,10,10,10,10,10,10,10],
         [10,10,10,10,10,250,250,250,250],
         [10,10,10,10,10,250,250,250,250],
         [10,10,250,250,250,250,250,250,250],
         [10,10,10,250,250,250,250,250,250],
         [10,10,10,10,250,250,250,250,250],
         [10,10,10,10,250,250,250,250,250],
         [10,10,10,10,250,250,250,250,250]]

def apply_moravec():
    value = [[0] * 9 for _ in range(9)]
    
    for y, x in itertools.product(range(9), range(9)):
        v = image[y][x]
        sum_ = 0
        for ty, tx in itertools.product([y - 1, y, y + 1], [x - 1, x, x + 1]):
            if tx < 0 or ty < 0 or tx >= 9 or ty >= 9:
                continue
            tv = image[ty][tx]
            sum_ += (tv - v) ** 2

        value[y][x] = sum_ / 8

    return value

def apply_susan():
    thresh = 10
    value = [[0] * 9 for _ in range(9)]

    for y, x in itertools.product(range(9), range(9)):
        v = image[y][x]
        count = 0
        for ty, tx in itertools.product([y - 1, y, y + 1], [x - 1, x, x + 1]):
            if tx < 0 or ty < 0 or tx >= 9 or ty >= 9:
                count += 1
                continue

            tv = image[ty][tx]
            if abs(tv - v) < 10:
                count += 1

        value[y][x] = count

    return value

def apply_fast():
    thresh = 10
    value = [[0] * 9 for _ in range(9)]

    for y, x in itertools.product(range(9), range(9)):
        v = image[y][x]
        pos = [(y - 1, x - 1), (y - 1, x), (y - 1, x + 1), (y , x + 1), (y + 1, x + 1), (y + 1, x), (y + 1, x - 1), (y, x - 1)]
        
        for i in range(len(pos)):
            for j in range(5):
                k = (i + j) % 8
                ty, tx = pos[k]
                if tx < 0 or ty < 0 or tx >= 9 or ty >= 9:
                    break
                tv = image[ty][tx]
                if abs(tv - v) >= 10:
                    pass
                else:
                    break
            else:
                value[y][x] = 1
                break

    return value

def apply_tomashi_kanade():
    import math
    
    def _dydy():
        prev = image[y - 1][x] if (y - 1) > 0 else image[y][x]
        next = image[y + 1][x] if (y + 1) < 9 else image[y][x]

        return prev - 2 * image[y][x] + next

    def _dxdx():
        prev = image[y][x - 1] if (x - 1) > 0 else image[y][x]
        next = image[y][x + 1] if (x + 1) < 9 else image[y][x]

        return prev - 2 * image[y][x] + next

    def _dxdy():
        prevx = image[y][x - 1] if (x - 1) > 0 else image[y][x]
        prevy = image[y - 1][x] if (y - 1) > 0 else image[y][x]

        return prevx - 2 * image[y][x] + prevy
        
    value = [[0] * 9 for _ in range(9)]

    for y, x in itertools.product(range(9), range(9)):
        dydy = _dydy()
        dxdx = _dxdx()
        dxdy = _dxdy()
        t = dxdx + dydy

        l1 = abs(t + math.sqrt(t ** 2 - 4 * (t - dxdy ** 2)))
        l2 = abs(t - math.sqrt(t ** 2 - 4 * (t - dxdy ** 2)))

        value[y][x] = min(l1, l2)

    return value

if __name__ == '__main__':
    print apply_moravec()
    print apply_susan()
    print apply_fast()
    print [map(lambda y: round(y, 1), x) for x in apply_tomashi_kanade()]
    

[[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 0.0, 240.0, 148.328, 148.328, 148.328], [0.0, 0.0, 0.0, 0.0, 240.0, 148.328, 0.0, 0.0, 0.0], [0.0, 0.0, 134.773, 148.328, 148.328, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 148.328, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 148.328, 0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0, 148.328, 0.0, 0.0, 0.0, 0.0]]