mirror of https://github.com/pyodide/pyodide.git
57 lines
1.9 KiB
Python
57 lines
1.9 KiB
Python
|
#from: http://continuum.io/blog/numba_performance
|
||
|
|
#setup: N = 10 ; import numpy as np ; image = np.random.rand(N, N, 3) ; state = np.zeros((N, N, 2)) ; state_next = np.empty_like(state) ; state[0, 0, 0] = state[0, 0, 1] = 1
|
||
|
|
#run: growcut(image, state, state_next, 2)
|
||
|
|
|
||
|
|
#pythran export growcut(float[][][], float[][][], float[][][], int)
|
||
|
|
import math
|
||
|
|
import numpy as np
|
||
|
|
def window_floor(idx, radius):
|
||
|
|
if radius > idx:
|
||
|
|
return 0
|
||
|
|
else:
|
||
|
|
return idx - radius
|
||
|
|
|
||
|
|
|
||
|
|
def window_ceil(idx, ceil, radius):
|
||
|
|
if idx + radius > ceil:
|
||
|
|
return ceil
|
||
|
|
else:
|
||
|
|
return idx + radius
|
||
|
|
|
||
|
|
def growcut(image, state, state_next, window_radius):
|
||
|
|
changes = 0
|
||
|
|
sqrt_3 = math.sqrt(3.0)
|
||
|
|
|
||
|
|
height = image.shape[0]
|
||
|
|
width = image.shape[1]
|
||
|
|
|
||
|
|
for j in range(width):
|
||
|
|
for i in range(height):
|
||
|
|
|
||
|
|
winning_colony = state[i, j, 0]
|
||
|
|
defense_strength = state[i, j, 1]
|
||
|
|
|
||
|
|
for jj in range(window_floor(j, window_radius),
|
||
|
|
window_ceil(j+1, width, window_radius)):
|
||
|
|
for ii in range(window_floor(i, window_radius),
|
||
|
|
window_ceil(i+1, height, window_radius)):
|
||
|
|
if (ii != i and jj != j):
|
||
|
|
d = image[i, j, 0] - image[ii, jj, 0]
|
||
|
|
s = d * d
|
||
|
|
for k in range(1, 3):
|
||
|
|
d = image[i, j, k] - image[ii, jj, k]
|
||
|
|
s += d * d
|
||
|
|
gval = 1.0 - math.sqrt(s)/sqrt_3
|
||
|
|
|
||
|
|
attack_strength = gval * state[ii, jj, 1]
|
||
|
|
|
||
|
|
if attack_strength > defense_strength:
|
||
|
|
defense_strength = attack_strength
|
||
|
|
winning_colony = state[ii, jj, 0]
|
||
|
|
changes += 1
|
||
|
|
|
||
|
|
state_next[i, j, 0] = winning_colony
|
||
|
|
state_next[i, j, 1] = defense_strength
|
||
|
|
|
||
|
|
return changes
|