CofeehousePy/deps/scikit-image/skimage/feature/orb_cy.pyx

51 lines
1.6 KiB
Cython

#cython: cdivision=True
#cython: boundscheck=False
#cython: nonecheck=False
#cython: wraparound=False
import numpy as np
from libc.math cimport sin, cos
from .._shared.interpolation cimport round
from .._shared.fused_numerics cimport np_floats
from ._orb_descriptor_positions import POS, POS0, POS1
def _orb_loop(np_floats[:, ::1] image, Py_ssize_t[:, ::1] keypoints,
np_floats[:] orientations):
cdef Py_ssize_t i, d, kr, kc, pr0, pr1, pc0, pc1, spr0, spc0, spr1, spc1
cdef np_floats angle, sin_a, cos_a
cdef unsigned char[:, ::1] descriptors = np.zeros(
(keypoints.shape[0], POS.shape[0]), dtype=np.uint8)
cdef signed char[:, ::1] cpos0 = POS0
cdef signed char[:, ::1] cpos1 = POS1
with nogil:
for i in range(descriptors.shape[0]):
angle = orientations[i]
sin_a = sin(angle)
cos_a = cos(angle)
kr = keypoints[i, 0]
kc = keypoints[i, 1]
for j in range(descriptors.shape[1]):
pr0 = cpos0[j, 0]
pc0 = cpos0[j, 1]
pr1 = cpos1[j, 0]
pc1 = cpos1[j, 1]
spr0 = <Py_ssize_t>round(sin_a * pr0 + cos_a * pc0)
spc0 = <Py_ssize_t>round(cos_a * pr0 - sin_a * pc0)
spr1 = <Py_ssize_t>round(sin_a * pr1 + cos_a * pc1)
spc1 = <Py_ssize_t>round(cos_a * pr1 - sin_a * pc1)
if image[kr + spr0, kc + spc0] < image[kr + spr1, kc + spc1]:
descriptors[i, j] = True
return np.asarray(descriptors)