File size: 8,313 Bytes
7615afe
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
from scipy.interpolate import interp1d, PchipInterpolator

import numpy as np
from PIL import Image
import cv2
import torch


def sift_match(
    img1, img2,
    thr=0.5, 
    topk=5, method="max_dist",
    output_path="sift_matches.png",
):
    
    assert method in ["max_dist", "random", "max_score", "max_score_even"]

    # img1 and img2 are PIL images
    # small threshold means less points

    # 1. to cv2 grayscale image
    img1_rgb = np.array(img1).copy()
    img2_rgb = np.array(img2).copy()
    img1 = cv2.cvtColor(np.array(img1), cv2.COLOR_RGB2BGR)
    img1 = cv2.cvtColor(img1, cv2.COLOR_BGR2GRAY)
    img2 = cv2.cvtColor(np.array(img2), cv2.COLOR_RGB2BGR)
    img2 = cv2.cvtColor(img2, cv2.COLOR_BGR2GRAY)

    # 2. use sift to extract keypoints and descriptors
    # Initiate SIFT detector
    sift = cv2.SIFT_create()
    # find the keypoints and descriptors with SIFT
    kp1, des1 = sift.detectAndCompute(img1, None)
    kp2, des2 = sift.detectAndCompute(img2, None)
    # BFMatcher with default params
    bf = cv2.BFMatcher()
    # bf = cv2.BFMatcher(cv2.NORM_L2, crossCheck=True)
    # bf = cv2.BFMatcher(cv2.NORM_HAMMING, crossCheck=True)
    matches = bf.knnMatch(des1, des2, k=2)

    # Apply ratio test
    good = []
    point_list = []
    distance_list = []

    if method in ['max_score', 'max_score_even']:
        matches = sorted(matches, key=lambda x: x[0].distance / x[1].distance)

        anchor_points_list = []
        for m, n in matches[:topk]:
            print(m.distance / n.distance)

            # check evenly distributed
            if method == 'max_score_even':
                to_close = False
                for anchor_point in anchor_points_list:
                    pt1 = kp1[m.queryIdx].pt
                    dist = np.linalg.norm(np.array(pt1) - np.array(anchor_point))
                    if dist < 50:
                        to_close = True
                        break
                if to_close:
                    continue

            good.append([m])

            pt1 = kp1[m.queryIdx].pt
            pt2 = kp2[m.trainIdx].pt
            dist = np.linalg.norm(np.array(pt1) - np.array(pt2))
            distance_list.append(dist)

            anchor_points_list.append(pt1)

            pt1 = torch.tensor(pt1)
            pt2 = torch.tensor(pt2)
            pt = torch.stack([pt1, pt2])  # (2, 2)
            point_list.append(pt)

    if method in ['max_dist', 'random']:
        for m, n in matches:
            if m.distance < thr * n.distance:
                good.append([m])

                pt1 = kp1[m.queryIdx].pt
                pt2 = kp2[m.trainIdx].pt
                dist = np.linalg.norm(np.array(pt1) - np.array(pt2))
                distance_list.append(dist)

                pt1 = torch.tensor(pt1)
                pt2 = torch.tensor(pt2)
                pt = torch.stack([pt1, pt2])  # (2, 2)
                point_list.append(pt)

        distance_list = np.array(distance_list)
        # only keep the points with the largest topk distance
        idx = np.argsort(distance_list)
        if method == "max_dist":
            idx = idx[-topk:]
        elif method == "random":
            topk = min(topk, len(idx))
            idx = np.random.choice(idx, topk, replace=False)
        elif method == "max_score":
            import pdb; pdb.set_trace()
            raise NotImplementedError
            # idx = np.argsort(distance_list)[:topk]
        else:
            raise ValueError(f"Unknown method {method}")

        point_list = [point_list[i] for i in idx]
        good = [good[i] for i in idx]

    # # cv2.drawMatchesKnn expects list of lists as matches.
    # draw_params = dict(
    #     matchColor=(255, 0, 0),
    #     singlePointColor=None,
    #     flags=2,
    # )
    # img3 = cv2.drawMatchesKnn(img1, kp1, img2, kp2, good, None, **draw_params)


    # # manually draw the matches, the images are put in horizontal
    # img3 = np.concatenate([img1_rgb, img2_rgb], axis=1)  # (h, 2w, 3)
    # for m in good:
    #     pt1 = kp1[m[0].queryIdx].pt
    #     pt2 = kp2[m[0].trainIdx].pt
    #     pt1 = (int(pt1[0]), int(pt1[1]))
    #     pt2 = (int(pt2[0]) + img1_rgb.shape[1], int(pt2[1]))
    #     cv2.line(img3, pt1, pt2, (255, 0, 0), 1)

    # manually draw the matches, the images are put in vertical. with 10 pixels margin
    margin = 10
    img3 = np.zeros((img1_rgb.shape[0] + img2_rgb.shape[0] + margin, max(img1_rgb.shape[1], img2_rgb.shape[1]), 3), dtype=np.uint8)
    # the margin is white
    img3[:, :] = 255
    img3[:img1_rgb.shape[0], :img1_rgb.shape[1]] = img1_rgb
    img3[img1_rgb.shape[0] + margin:, :img2_rgb.shape[1]] = img2_rgb
    # create a color list of 6 different colors
    color_list = [(255, 0, 0), (0, 255, 0), (0, 0, 255), (255, 255, 0), (0, 255, 255), (255, 0, 255)]
    for color_idx, m in enumerate(good):
        pt1 = kp1[m[0].queryIdx].pt
        pt2 = kp2[m[0].trainIdx].pt
        pt1 = (int(pt1[0]), int(pt1[1]))
        pt2 = (int(pt2[0]), int(pt2[1]) + img1_rgb.shape[0] + margin)
        # cv2.line(img3, pt1, pt2, (255, 0, 0), 1)
        # avoid the zigzag artifact in line
        # random_color = tuple(np.random.randint(0, 255, 3).tolist())
        color = color_list[color_idx % len(color_list)]
        cv2.line(img3, pt1, pt2, color, 1, lineType=cv2.LINE_AA)
        # add a empty circle to both start and end points
        cv2.circle(img3, pt1, 3, color, lineType=cv2.LINE_AA)
        cv2.circle(img3, pt2, 3, color, lineType=cv2.LINE_AA)

    Image.fromarray(img3).save(output_path)
    print(f"Save the sift matches to {output_path}")

    # (f, topk, 2), f=2 (before interpolation)
    if len(point_list) == 0:
        return None

    point_list = torch.stack(point_list)
    point_list = point_list.permute(1, 0, 2)

    return point_list


def interpolate_trajectory(points_torch, num_frames, t=None):
    # points:(f, topk, 2), f=2 (before interpolation)

    num_points = points_torch.shape[1]
    points_torch = points_torch.permute(1, 0, 2)  # (topk, f, 2)

    points_list = []
    for i in range(num_points):
        # points:(f, 2)
        points = points_torch[i].cpu().numpy()

        x = [point[0] for point in points]
        y = [point[1] for point in points]

        if t is None:
            t = np.linspace(0, 1, len(points))

        # fx = interp1d(t, x, kind='cubic')
        # fy = interp1d(t, y, kind='cubic')
        fx = PchipInterpolator(t, x)
        fy = PchipInterpolator(t, y)

        new_t = np.linspace(0, 1, num_frames)

        new_x = fx(new_t)
        new_y = fy(new_t)
        new_points = list(zip(new_x, new_y))

        points_list.append(new_points)

    points = torch.tensor(points_list)  # (topk, num_frames, 2)
    points = points.permute(1, 0, 2)  # (num_frames, topk, 2)

    return points


# diffusion feature matching
def point_tracking(
    F0,
    F1,
    handle_points,
    handle_points_init,
    track_dist=5,
):
    # handle_points: (num_points, 2)
    # NOTE: 
    # 1. all row and col are reversed 
    # 2. handle_points in (y, x), not (x, y)

    # reverse row and col
    handle_points = torch.stack([handle_points[:, 1], handle_points[:, 0]], dim=-1)
    handle_points_init = torch.stack([handle_points_init[:, 1], handle_points_init[:, 0]], dim=-1)

    with torch.no_grad():
        _, _, max_r, max_c = F0.shape

        for i in range(len(handle_points)):
            pi0, pi = handle_points_init[i], handle_points[i]
            f0 = F0[:, :, int(pi0[0]), int(pi0[1])]

            r1, r2 = max(0, int(pi[0]) - track_dist), min(max_r, int(pi[0]) + track_dist + 1)
            c1, c2 = max(0, int(pi[1]) - track_dist), min(max_c, int(pi[1]) + track_dist + 1)
            F1_neighbor = F1[:, :, r1:r2, c1:c2]
            all_dist = (f0.unsqueeze(dim=-1).unsqueeze(dim=-1) - F1_neighbor).abs().sum(dim=1)
            all_dist = all_dist.squeeze(dim=0)
            row, col = divmod(all_dist.argmin().item(), all_dist.shape[-1])
            # handle_points[i][0] = pi[0] - track_dist + row
            # handle_points[i][1] = pi[1] - track_dist + col
            handle_points[i][0] = r1 + row
            handle_points[i][1] = c1 + col

        handle_points = torch.stack([handle_points[:, 1], handle_points[:, 0]], dim=-1)  # (num_points, 2)

        return handle_points