File size: 6,136 Bytes
a80d6bb
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import logging
import os
import cv2
import torch
from copy import deepcopy
import torch.nn.functional as F
from torchvision.transforms import ToTensor
import math

from alnet import ALNet
from soft_detect import DKD
import time

configs = {
    'alike-t': {'c1': 8, 'c2': 16, 'c3': 32, 'c4': 64, 'dim': 64, 'single_head': True, 'radius': 2,
                'model_path': os.path.join(os.path.split(__file__)[0], 'models', 'alike-t.pth')},
    'alike-s': {'c1': 8, 'c2': 16, 'c3': 48, 'c4': 96, 'dim': 96, 'single_head': True, 'radius': 2,
                'model_path': os.path.join(os.path.split(__file__)[0], 'models', 'alike-s.pth')},
    'alike-n': {'c1': 16, 'c2': 32, 'c3': 64, 'c4': 128, 'dim': 128, 'single_head': True, 'radius': 2,
                'model_path': os.path.join(os.path.split(__file__)[0], 'models', 'alike-n.pth')},
    'alike-l': {'c1': 32, 'c2': 64, 'c3': 128, 'c4': 128, 'dim': 128, 'single_head': False, 'radius': 2,
                'model_path': os.path.join(os.path.split(__file__)[0], 'models', 'alike-l.pth')},
}


class ALike(ALNet):
    def __init__(self,
                 # ================================== feature encoder
                 c1: int = 32, c2: int = 64, c3: int = 128, c4: int = 128, dim: int = 128,
                 single_head: bool = False,
                 # ================================== detect parameters
                 radius: int = 2,
                 top_k: int = 500, scores_th: float = 0.5,
                 n_limit: int = 5000,
                 device: str = 'cpu',
                 model_path: str = ''
                 ):
        super().__init__(c1, c2, c3, c4, dim, single_head)
        self.radius = radius
        self.top_k = top_k
        self.n_limit = n_limit
        self.scores_th = scores_th
        self.dkd = DKD(radius=self.radius, top_k=self.top_k,
                       scores_th=self.scores_th, n_limit=self.n_limit)
        self.device = device

        if model_path != '':
            state_dict = torch.load(model_path, self.device)
            self.load_state_dict(state_dict)
            self.to(self.device)
            self.eval()
            logging.info(f'Loaded model parameters from {model_path}')
            logging.info(
                f"Number of model parameters: {sum(p.numel() for p in self.parameters() if p.requires_grad) / 1e3}KB")

    def extract_dense_map(self, image, ret_dict=False):
        # ====================================================
        # check image size, should be integer multiples of 2^5
        # if it is not a integer multiples of 2^5, padding zeros
        device = image.device
        b, c, h, w = image.shape
        h_ = math.ceil(h / 32) * 32 if h % 32 != 0 else h
        w_ = math.ceil(w / 32) * 32 if w % 32 != 0 else w
        if h_ != h:
            h_padding = torch.zeros(b, c, h_ - h, w, device=device)
            image = torch.cat([image, h_padding], dim=2)
        if w_ != w:
            w_padding = torch.zeros(b, c, h_, w_ - w, device=device)
            image = torch.cat([image, w_padding], dim=3)
        # ====================================================

        scores_map, descriptor_map = super().forward(image)

        # ====================================================
        if h_ != h or w_ != w:
            descriptor_map = descriptor_map[:, :, :h, :w]
            scores_map = scores_map[:, :, :h, :w]  # Bx1xHxW
        # ====================================================

        # BxCxHxW
        descriptor_map = torch.nn.functional.normalize(descriptor_map, p=2, dim=1)

        if ret_dict:
            return {'descriptor_map': descriptor_map, 'scores_map': scores_map, }
        else:
            return descriptor_map, scores_map

    def forward(self, img, image_size_max=99999, sort=False, sub_pixel=False):
        """
        :param img: np.array HxWx3, RGB
        :param image_size_max: maximum image size, otherwise, the image will be resized
        :param sort: sort keypoints by scores
        :param sub_pixel: whether to use sub-pixel accuracy
        :return: a dictionary with 'keypoints', 'descriptors', 'scores', and 'time'
        """
        H, W, three = img.shape
        assert three == 3, "input image shape should be [HxWx3]"

        # ==================== image size constraint
        image = deepcopy(img)
        max_hw = max(H, W)
        if max_hw > image_size_max:
            ratio = float(image_size_max / max_hw)
            image = cv2.resize(image, dsize=None, fx=ratio, fy=ratio)

        # ==================== convert image to tensor
        image = torch.from_numpy(image).to(self.device).to(torch.float32).permute(2, 0, 1)[None] / 255.0

        # ==================== extract keypoints
        start = time.time()

        with torch.no_grad():
            descriptor_map, scores_map = self.extract_dense_map(image)
            keypoints, descriptors, scores, _ = self.dkd(scores_map, descriptor_map,
                                                         sub_pixel=sub_pixel)
            keypoints, descriptors, scores = keypoints[0], descriptors[0], scores[0]
            keypoints = (keypoints + 1) / 2 * keypoints.new_tensor([[W - 1, H - 1]])

        if sort:
            indices = torch.argsort(scores, descending=True)
            keypoints = keypoints[indices]
            descriptors = descriptors[indices]
            scores = scores[indices]

        end = time.time()

        return {'keypoints': keypoints.cpu().numpy(),
                'descriptors': descriptors.cpu().numpy(),
                'scores': scores.cpu().numpy(),
                'scores_map': scores_map.cpu().numpy(),
                'time': end - start, }


if __name__ == '__main__':
    import numpy as np
    from thop import profile

    net = ALike(c1=32, c2=64, c3=128, c4=128, dim=128, single_head=False)

    image = np.random.random((640, 480, 3)).astype(np.float32)
    flops, params = profile(net, inputs=(image, 9999, False), verbose=False)
    print('{:<30}  {:<8} GFLops'.format('Computational complexity: ', flops / 1e9))
    print('{:<30}  {:<8} KB'.format('Number of parameters: ', params / 1e3))