1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
import cv2
import imutils
import numpy as np
def order_points(pts):
rect = np.zeros((4, 2), dtype="float32")
s = pts.sum(axis=1)
rect[0] = pts[np.argmin(s)]
rect[2] = pts[np.argmax(s)]
diff = np.diff(pts, axis=1)
rect[1] = pts[np.argmin(diff)]
rect[3] = pts[np.argmax(diff)]
return rect
def four_point_transform(image, pts):
rect = order_points(pts)
(tl, tr, br, bl) = rect
width_a = np.sqrt(((br[0] - bl[0]) ** 2) + ((br[1] - bl[1]) ** 2))
width_b = np.sqrt(((tr[0] - tl[0]) ** 2) + ((tr[1] - tl[1]) ** 2))
max_width = max(int(width_a), int(width_b))
height_a = np.sqrt(((tr[0] - br[0]) ** 2) + ((tr[1] - br[1]) ** 2))
height_b = np.sqrt(((tl[0] - bl[0]) ** 2) + ((tl[1] - bl[1]) ** 2))
max_height = max(int(height_a), int(height_b))
dst = np.array([
[0, 0],
[max_width - 1, 0],
[max_width - 1, max_height - 1],
[0, max_height - 1]], dtype="float32")
transformation = cv2.getPerspectiveTransform(rect, dst)
warped = cv2.warpPerspective(image, transformation, (max_width, max_height))
return warped
def align_images(im1, im2):
im1_gra = cv2.cvtColor(im1, cv2.COLOR_BGR2GRAY)
im2_gray = cv2.cvtColor(im2, cv2.COLOR_BGR2GRAY)
orb = cv2.ORB_create(500)
keypoints1, descriptors1 = orb.detectAndCompute(im1_gra, None)
keypoints2, descriptors2 = orb.detectAndCompute(im2_gray, None)
matcher = cv2.DescriptorMatcher_create(cv2.DESCRIPTOR_MATCHER_BRUTEFORCE_HAMMING)
matches = matcher.match(descriptors1, descriptors2, None)
matches.sort(key=lambda x: x.distance, reverse=False)
num_good_matches = int(len(matches) * 0.15)
matches = matches[:num_good_matches]
im_matches = cv2.drawMatches(im1, keypoints1, im2, keypoints2, matches, None)
cv2.imwrite("matches.jpg", im_matches)
points1 = np.zeros((len(matches), 2), dtype=np.float32)
points2 = np.zeros((len(matches), 2), dtype=np.float32)
for i, match in enumerate(matches):
points1[i, :] = keypoints1[match.queryIdx].pt
points2[i, :] = keypoints2[match.trainIdx].pt
h, mask = cv2.findHomography(points1, points2, cv2.RANSAC)
height, width, channels = im2.shape
im1_reg = cv2.warpPerspective(im1, h, (width, height))
return im1_reg, h
if __name__ == '__main__':
image = cv2.imread("example.jpg")
ratio = image.shape[0] / 500.0
orig = image.copy()
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
gray = cv2.GaussianBlur(gray, (5, 5), 0)
edged = cv2.Canny(gray, 75, 200)
cnts = cv2.findContours(edged.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
cnts = imutils.grab_contours(cnts)
cnts = sorted(cnts, key=cv2.contourArea, reverse=True)[:5]
for c in cnts:
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.02 * peri, True)
if len(approx) == 4:
screenCnt = approx
break
cv2.drawContours(image, [screenCnt], -1, (0, 255, 0), 2)
warped = four_point_transform(orig, screenCnt.reshape(4, 2) * ratio)
cv2.imwrite("before.jpg", warped)
# cv2.imshow("Original", imutils.resize(orig, height=650))
# cv2.imshow("Scanned", imutils.resize(warped, height=650))
# cv2.waitKey(0)
ref_filename = "mask.jpg"
im_reference = cv2.imread(ref_filename, cv2.IMREAD_COLOR)
warped, h = align_images(warped, im_reference)
print("Estimated homography : \n", h)
out_filename = "aligned.jpg"
cv2.imwrite(out_filename, warped)
|
