我是python的新手，我正在尝试运行以下代码：
"""
Thanks to Aron Ahmadia
"""
from __future__ import division, print_function
import sys
import math
import numba
from numba import jit, autojit, size_t
import numpy as np
import numpy.testing as npt
try:
from skimage import img_as_float
except ImportError as e:
print("skimage not available, skipping")
sys.exit()
SCALAR_DTYPE = np.float64
# This doesn't work :(
# SCALAR_TYPE = numba.typeof(SCALAR_DTYPE)
SCALAR_TYPE = numba.float64
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 distance(image, r0, c0, r1, c1):
d = image[r0, c0, 0] - image[r1, c1, 0]
s = d * d
for i in range(1, 3):
d = image[r0, c0, i] - image[r1, c1, i]
s += d * d
return math.sqrt(s)
def pixel_distance(pixel1, pixel2):
d = pixel1[0] - pixel2[0]
s = d*d
for i in range(1, 3):
d = pixel1[i] - pixel2[i]
s += d*d
return math.sqrt(s)
def np_distance(pixel1, pixel2):
return np.linalg.norm(pixel1-pixel2, 2)
sqrt_3 = math.sqrt(3.0)
def g(d):
return 1.0 - d/sqrt_3
def np_g(x, y):
return 1.0 - np_distance(x, y)/sqrt_3
def kernel(image, state, state_next, window_radius):
changes = 0
height = image.shape[0]
width = image.shape[1]
for j in xrange(width):
for i in xrange(height):
winning_colony = state[i, j, 0]
defense_strength = state[i, j, 1]
for jj in xrange(window_floor(j, window_radius),
window_ceil(j+1, width, window_radius)):
for ii in xrange(window_floor(i, window_radius),
window_ceil(i+1, height, window_radius)):
if (ii == i and jj == j):
continue
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
def growcut(image, state, max_iter=20, window_size=3):
"""Grow-cut segmentation (Numba accelerated).
Parameters
----------
image : (M, N) ndarray
Input image.
state : (M, N, 2) ndarray
Initial state, which stores (foreground/background, strength) for
each pixel position or automaton. The strength represents the
certainty of the state (e.g., 1 is a hard seed value that remains
constant throughout segmentation).
max_iter : int, optional
The maximum number of automata iterations to allow. The segmentation
may complete earlier if the state no longer varies.
window_size : int, optional
Size of the neighborhood window.
Returns
-------
mask : ndarray
Segmented image. A value of zero indicates background, one foreground.
"""
image = img_as_float(image)
window_radius = (window_size - 1) // 2
changes = 1
n = 0
state_next = np.empty_like(state)
while changes > 0 and n < max_iter:
changes = 0
n += 1
changes = kernel(image, state, state_next, window_radius)
state_next, state = state, state_next
#print n, changes
print('.', end='')
print('')
return state_next[:, :, 0]
def create_numba_funcs(scalar_type=SCALAR_TYPE):
this = sys.modules[__name__]
pixel_type = scalar_type[:]
image_type = scalar_type[:, :, :]
state_type = scalar_type[:, :, :]
this._numba_window_floor = jit(nopython=True,
argtypes=[size_t, size_t],
restype=size_t)(_py_window_floor)
this._numba_window_ceil = jit(nopython=True,
argtypes=[size_t, size_t, size_t],
restype=size_t)(_py_window_ceil)
this._numba_distance = jit(nopython=True,
argtypes=[image_type,
size_t, size_t, size_t, size_t],
restype=scalar_type)(_py_distance)
this._numba_np_distance = jit(nopython=False,
argtypes=[pixel_type, pixel_type],
restype=scalar_type)(_py_np_distance)
this._numba_g = jit(nopython=True,
argtypes=[scalar_type],
restype=scalar_type)(_py_g)
this._numba_np_g = jit(nopython=False,
argtypes=[pixel_type, pixel_type],
restype=scalar_type)(_py_np_g)
this._numba_kernel = autojit(nopython=True)(_py_kernel)
# the below code does not work
# this._numba_kernel = jit(nopython=False,
# argtypes=[image_type,
# state_type,
# state_type,
# size_t],
# restype=int_,
# attack_strength=scalar_type,
# defense_strength=scalar_type,
# winning_colony=scalar_type)(_py_kernel)
def debug():
this = sys.modules[__name__]
this.window_floor = _py_window_floor
this.window_ceil = _py_window_ceil
this.distance = _py_distance
this.np_distance = _py_np_distance
this.g = _py_g
this.np_g = _py_np_g
this.kernel = _py_kernel
def optimize():
this = sys.modules[__name__]
this.window_floor = _numba_window_floor
this.window_ceil = _numba_window_ceil
this.distance = _numba_distance
this.np_distance = _numba_np_distance
this.g = _numba_g
this.np_g = _numba_np_g
this.kernel = _numba_kernel
# protected Pythonic versions of code:
_py_window_floor = window_floor
_py_window_ceil = window_ceil
_py_distance = distance
_py_np_distance = np_distance
_py_g = g
_py_np_g = np_g
_py_kernel = kernel
def test_window_floor_ceil():
assert 3 == window_floor(4, 1)
assert 0 == window_floor(1, 4)
assert 3 == window_ceil(3, 3, 1)
assert 5 == window_ceil(4, 5, 1)
def test_distance():
image = np.zeros((2, 2, 3), dtype=SCALAR_DTYPE)
image[0, 1] = [1, 1, 1]
image[1, 0] = [0.5, 0.5, 0.5]
assert 0.0 == distance(image, 0, 0, 0, 0)
assert abs(math.sqrt(3) - distance(image, 0, 0, 0, 1)) < 1e-15
assert abs(math.sqrt(3/4) - distance(image, 0, 1, 1, 0)) < 1e-15
pixel1 = np.asarray([0.0, 0.0, 0.0], dtype=SCALAR_DTYPE)
pixel2 = np.asarray([1.0, 1.0, 1.0], dtype=SCALAR_DTYPE)
pixel3 = np.asarray([0.5, 0.5, 0.5], dtype=SCALAR_DTYPE)
assert 0.0 == np_distance(pixel1, pixel1)
assert abs(math.sqrt(3) - np_distance(pixel1, pixel2)) < 1e-15
assert abs(math.sqrt(3/4) - np_distance(pixel2, pixel3)) < 1e-15
def test_g():
image = np.zeros((2, 2, 3), dtype=SCALAR_DTYPE)
image[0, 1] = [1, 1, 1]
image[1, 0] = [0.5, 0.5, 0.5]
assert 1.0 == g(distance(image, 0, 0, 0, 0))
assert abs(0 - g(distance(image, 0, 0, 0, 1))) < 1e-15
assert abs(0.5 - g(distance(image, 0, 1, 1, 0))) < 1e-15
pixel1 = np.asarray([0.0, 0.0, 0.0], dtype=SCALAR_DTYPE)
pixel2 = np.asarray([1.0, 1.0, 1.0], dtype=SCALAR_DTYPE)
pixel3 = np.asarray([0.5, 0.5, 0.5], dtype=SCALAR_DTYPE)
assert 1.0 == np_g(pixel1, pixel1)
assert abs(0 - np_g(pixel1, pixel2)) < 1e-15
assert abs(0.5 - np_g(pixel2, pixel3)) < 1e-15
def test_kernel():
image = np.zeros((3, 3, 3), dtype=SCALAR_DTYPE)
state = np.zeros((3, 3, 2), dtype=SCALAR_DTYPE)
state_next = np.empty_like(state)
# colony 1 is strength 1 at position 0,0
# colony 0 is strength 0 at all other positions
state[0, 0, 0] = 1
state[0, 0, 1] = 1
# window_size 1, colony 1 should propagate to three neighbors
changes = kernel(image, state, state_next, 1)
assert(3 == changes)
npt.assert_array_equal(state_next[0:2, 0:2], 1)
npt.assert_array_equal(state_next[2, :], 0)
npt.assert_array_equal(state_next[2, :], 0)
# window_size 1, colony 1 should propagate to entire image
changes = kernel(image, state, state_next, 2)
assert(8 == changes)
npt.assert_array_equal(state_next, 1)
def test():
test_window_floor_ceil()
test_distance()
test_g()
test_kernel()
# create numba versions of code
create_numba_funcs()
if __name__ == "__main__":
# always verify pure Python code first
test()
# then test optimized variants
optimize()
test()
# replace default function calls with numba calls
optimize()
我的问题是，当我尝试从numba导入size_t时，我收到了“未解析的引用”错误。有人可以帮我解决这个问题吗？
谢谢！