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scikit-image/skimage/feature/tests/test_brief.py
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import numpy as np
from numpy.testing import assert_array_equal, assert_raises
from skimage import data
from skimage import transform as tf
from skimage.feature.corner import corner_peaks, corner_harris
from skimage.color import rgb2gray
from skimage.feature import brief, match_keypoints_brief
def test_brief_color_image_unsupported_error():
"""Brief descriptors can be evaluated on gray-scale images only."""
img = np.zeros((20, 20, 3))
keypoints = [[7, 5], [11, 13]]
assert_raises(ValueError, brief, img, keypoints)
def test_match_keypoints_brief_lena_translation():
"""Test matched keypoints between lena image and its translated version."""
img = data.lena()
img = rgb2gray(img)
img.shape
tform = tf.SimilarityTransform(scale=1, rotation=0, translation=(15, 20))
translated_img = tf.warp(img, tform)
keypoints1 = corner_peaks(corner_harris(img), min_distance=5)
descriptors1, keypoints1 = brief(img, keypoints1, descriptor_size=512)
keypoints2 = corner_peaks(corner_harris(translated_img), min_distance=5)
descriptors2, keypoints2 = brief(translated_img, keypoints2,
descriptor_size=512)
matched_keypoints = match_keypoints_brief(keypoints1, descriptors1,
keypoints2, descriptors2,
threshold=0.10)
assert_array_equal(matched_keypoints[0,::], matched_keypoints[1,::] +
[20, 15])
def test_match_keypoints_brief_lena_rotation():
"""Verify matched keypoints result between lena image and its rotated version
with the expected keypoint pairs."""
img = data.lena()
img = rgb2gray(img)
img.shape
tform = tf.SimilarityTransform(scale=1, rotation=0.10, translation=(0, 0))
rotated_img = tf.warp(img, tform)
keypoints1 = corner_peaks(corner_harris(img), min_distance=5)
descriptors1, keypoints1 = brief(img, keypoints1, descriptor_size=512)
keypoints2 = corner_peaks(corner_harris(rotated_img), min_distance=5)
descriptors2, keypoints2 = brief(rotated_img, keypoints2,
descriptor_size=512)
matched_keypoints = match_keypoints_brief(keypoints1, descriptors1,
keypoints2, descriptors2,
threshold=0.07)
expected = np.array([[[248, 147],
[263, 272],
[271, 120],
[414, 70],
[454, 176]],
[[232, 171],
[234, 298],
[258, 146],
[405, 111],
[435, 221]]])
assert_array_equal(matched_keypoints, expected)