File size: 10,875 Bytes
c2a846f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F

from models.submodules import Encoder, ConvGRU, UpSampleBN, UpSampleGN, RayReLU, \
                                convex_upsampling, get_unfold, get_prediction_head, \
                                INPUT_CHANNELS_DICT
from utils.rotation import axis_angle_to_matrix


class Decoder(nn.Module):
    def __init__(self, output_dims, B=5, NF=2048, BN=False, downsample_ratio=8):
        super(Decoder, self).__init__()
        input_channels = INPUT_CHANNELS_DICT[B]
        output_dim, feature_dim, hidden_dim = output_dims
        features = bottleneck_features = NF
        self.downsample_ratio = downsample_ratio

        UpSample = UpSampleBN if BN else UpSampleGN 
        self.conv2 = nn.Conv2d(bottleneck_features + 2, features, kernel_size=1, stride=1, padding=0)
        self.up1 = UpSample(skip_input=features // 1 + input_channels[1] + 2, output_features=features // 2, align_corners=False)
        self.up2 = UpSample(skip_input=features // 2 + input_channels[2] + 2, output_features=features // 4, align_corners=False)

        # prediction heads
        i_dim = features // 4
        h_dim = 128
        self.normal_head = get_prediction_head(i_dim+2, h_dim, output_dim)
        self.feature_head = get_prediction_head(i_dim+2, h_dim, feature_dim)
        self.hidden_head = get_prediction_head(i_dim+2, h_dim, hidden_dim)

    def forward(self, features, uvs):
        _, _, x_block2, x_block3, x_block4 = features[4], features[5], features[6], features[8], features[11]
        uv_32, uv_16, uv_8 = uvs

        x_d0 = self.conv2(torch.cat([x_block4, uv_32], dim=1))
        x_d1 = self.up1(x_d0, torch.cat([x_block3, uv_16], dim=1))
        x_feat = self.up2(x_d1, torch.cat([x_block2, uv_8], dim=1))
        x_feat = torch.cat([x_feat, uv_8], dim=1)

        normal = self.normal_head(x_feat)
        normal = F.normalize(normal, dim=1)
        f = self.feature_head(x_feat)
        h = self.hidden_head(x_feat)
        return normal, f, h


class DSINE(nn.Module):
    def __init__(self):
        super(DSINE, self).__init__()
        self.downsample_ratio = 8
        self.ps = 5           # patch size
        self.num_iter = 5     # num iterations

        # define encoder
        self.encoder = Encoder(B=5, pretrained=True)

        # define decoder
        self.output_dim = output_dim = 3
        self.feature_dim = feature_dim = 64
        self.hidden_dim = hidden_dim = 64
        self.decoder = Decoder([output_dim, feature_dim, hidden_dim], B=5, NF=2048, BN=False)

        # ray direction-based ReLU
        self.ray_relu = RayReLU(eps=1e-2)

        # pixel_coords (1, 3, H, W)
        # NOTE: this is set to some arbitrarily high number, 
        # if your input is 2000+ pixels wide/tall, increase these values
        h = 2000
        w = 2000
        pixel_coords = np.ones((3, h, w)).astype(np.float32)
        x_range = np.concatenate([np.arange(w).reshape(1, w)] * h, axis=0)
        y_range = np.concatenate([np.arange(h).reshape(h, 1)] * w, axis=1)
        pixel_coords[0, :, :] = x_range + 0.5
        pixel_coords[1, :, :] = y_range + 0.5
        self.pixel_coords = torch.from_numpy(pixel_coords).unsqueeze(0)

        # define ConvGRU cell
        self.gru = ConvGRU(hidden_dim=hidden_dim, input_dim=feature_dim+2, ks=self.ps)

        # padding used during NRN
        self.pad = (self.ps - 1) // 2

        # prediction heads
        self.prob_head = get_prediction_head(self.hidden_dim+2, 64, self.ps*self.ps)   # weights assigned for each nghbr pixel 
        self.xy_head = get_prediction_head(self.hidden_dim+2, 64, self.ps*self.ps*2)   # rotation axis for each nghbr pixel
        self.angle_head = get_prediction_head(self.hidden_dim+2, 64, self.ps*self.ps)  # rotation angle for each nghbr pixel

        # prediction heads - weights used for upsampling the coarse resolution output
        self.up_prob_head = get_prediction_head(self.hidden_dim+2, 64, 9 * self.downsample_ratio * self.downsample_ratio)

    def get_ray(self, intrins, H, W, orig_H, orig_W, return_uv=False):
        B, _, _ = intrins.shape
        fu = intrins[:, 0, 0][:,None,None] * (W / orig_W)
        cu = intrins[:, 0, 2][:,None,None] * (W / orig_W)
        fv = intrins[:, 1, 1][:,None,None] * (H / orig_H)
        cv = intrins[:, 1, 2][:,None,None] * (H / orig_H)

        # (B, 2, H, W)
        ray = self.pixel_coords[:, :, :H, :W].repeat(B, 1, 1, 1)
        ray[:, 0, :, :] = (ray[:, 0, :, :] - cu) / fu
        ray[:, 1, :, :] = (ray[:, 1, :, :] - cv) / fv

        if return_uv:
            return ray[:, :2, :, :]
        else:
            return F.normalize(ray, dim=1)

    def upsample(self, h, pred_norm, uv_8):
        up_mask = self.up_prob_head(torch.cat([h, uv_8], dim=1))
        up_pred_norm = convex_upsampling(pred_norm, up_mask, self.downsample_ratio)
        up_pred_norm = F.normalize(up_pred_norm, dim=1)
        return up_pred_norm

    def refine(self, h, feat_map, pred_norm, intrins, orig_H, orig_W, uv_8, ray_8):
        B, C, H, W = pred_norm.shape
        fu = intrins[:, 0, 0][:,None,None,None] * (W / orig_W)  # (B, 1, 1, 1)
        cu = intrins[:, 0, 2][:,None,None,None] * (W / orig_W)
        fv = intrins[:, 1, 1][:,None,None,None] * (H / orig_H)
        cv = intrins[:, 1, 2][:,None,None,None] * (H / orig_H)

        h_new = self.gru(h, feat_map)

        # get nghbr prob (B, 1, ps*ps, h, w)
        nghbr_prob = self.prob_head(torch.cat([h_new, uv_8], dim=1)).unsqueeze(1)
        nghbr_prob = torch.sigmoid(nghbr_prob)

        # get nghbr normals (B, 3, ps*ps, h, w)
        nghbr_normals = get_unfold(pred_norm, ps=self.ps, pad=self.pad)

        # get nghbr xy (B, 2, ps*ps, h, w)
        nghbr_xys = self.xy_head(torch.cat([h_new, uv_8], dim=1))
        nghbr_xs, nghbr_ys = torch.split(nghbr_xys, [self.ps*self.ps, self.ps*self.ps], dim=1)
        nghbr_xys = torch.cat([nghbr_xs.unsqueeze(1), nghbr_ys.unsqueeze(1)], dim=1)        
        nghbr_xys = F.normalize(nghbr_xys, dim=1)

        # get nghbr theta (B, 1, ps*ps, h, w)
        nghbr_angle = self.angle_head(torch.cat([h_new, uv_8], dim=1)).unsqueeze(1)
        nghbr_angle = torch.sigmoid(nghbr_angle) * np.pi

        # get nghbr pixel coord (1, 3, ps*ps, h, w)
        nghbr_pixel_coord = get_unfold(self.pixel_coords[:, :, :H, :W], ps=self.ps, pad=self.pad)

        # nghbr axes (B, 3, ps*ps, h, w)
        nghbr_axes = torch.zeros_like(nghbr_normals)

        du_over_fu = nghbr_xys[:, 0, ...] / fu                                      # (B, ps*ps, h, w)
        dv_over_fv = nghbr_xys[:, 1, ...] / fv                                      # (B, ps*ps, h, w)

        term_u = (nghbr_pixel_coord[:, 0, ...] + nghbr_xys[:, 0, ...] - cu) / fu    # (B, ps*ps, h, w)
        term_v = (nghbr_pixel_coord[:, 1, ...] + nghbr_xys[:, 1, ...] - cv) / fv    # (B, ps*ps, h, w)

        nx = nghbr_normals[:, 0, ...]                                               # (B, ps*ps, h, w)
        ny = nghbr_normals[:, 1, ...]                                               # (B, ps*ps, h, w)
        nz = nghbr_normals[:, 2, ...]                                               # (B, ps*ps, h, w)

        nghbr_delta_z_num = - (du_over_fu * nx + dv_over_fv * ny)
        nghbr_delta_z_denom = (term_u * nx + term_v * ny + nz)
        nghbr_delta_z_denom[torch.abs(nghbr_delta_z_denom) < 1e-8] = 1e-8 * torch.sign(nghbr_delta_z_denom[torch.abs(nghbr_delta_z_denom) < 1e-8])
        nghbr_delta_z = nghbr_delta_z_num / nghbr_delta_z_denom

        nghbr_axes[:, 0, ...] = du_over_fu + nghbr_delta_z * term_u
        nghbr_axes[:, 1, ...] = dv_over_fv + nghbr_delta_z * term_v
        nghbr_axes[:, 2, ...] = nghbr_delta_z
        nghbr_axes = F.normalize(nghbr_axes, dim=1)                                 # (B, 3, ps*ps, h, w)

        # make sure axes are all valid
        invalid = torch.sum(torch.logical_or(torch.isnan(nghbr_axes), torch.isinf(nghbr_axes)).float(), dim=1) > 0.5    # (B, ps*ps, h, w)
        nghbr_axes[:, 0, ...][invalid] = 0.0
        nghbr_axes[:, 1, ...][invalid] = 0.0
        nghbr_axes[:, 2, ...][invalid] = 0.0

        # nghbr_axes_angle (B, 3, ps*ps, h, w)
        nghbr_axes_angle = nghbr_axes * nghbr_angle
        nghbr_axes_angle = nghbr_axes_angle.permute(0, 2, 3, 4, 1)  # (B, ps*ps, h, w, 3)
        nghbr_R = axis_angle_to_matrix(nghbr_axes_angle)            # (B, ps*ps, h, w, 3, 3)

        # (B, 3, ps*ps, h, w)
        nghbr_normals_rot = torch.bmm(
            nghbr_R.reshape(B * self.ps * self.ps * H * W, 3, 3),
            nghbr_normals.permute(0, 2, 3, 4, 1).reshape(B * self.ps * self.ps * H * W, 3).unsqueeze(-1)
        ).reshape(B, self.ps*self.ps, H, W, 3, 1).squeeze(-1).permute(0, 4, 1, 2, 3)        # (B, 3, ps*ps, h, w)
        nghbr_normals_rot = F.normalize(nghbr_normals_rot, dim=1)

        # ray ReLU
        nghbr_normals_rot = torch.cat([
            self.ray_relu(nghbr_normals_rot[:, :, i, :, :], ray_8).unsqueeze(2) 
            for i in range(nghbr_normals_rot.size(2))
            ], dim=2)

        # (B, 1, ps*ps, h, w) * (B, 3, ps*ps, h, w)
        pred_norm = torch.sum(nghbr_prob * nghbr_normals_rot, dim=2)    # (B, C, H, W)
        pred_norm = F.normalize(pred_norm, dim=1)
    
        up_mask = self.up_prob_head(torch.cat([h_new, uv_8], dim=1))
        up_pred_norm = convex_upsampling(pred_norm, up_mask, self.downsample_ratio)
        up_pred_norm = F.normalize(up_pred_norm, dim=1)

        return h_new, pred_norm, up_pred_norm

    
    def forward(self, img, intrins=None):
        # Step 1. encoder
        features = self.encoder(img)

        # Step 2. get uv encoding
        B, _, orig_H, orig_W = img.shape
        intrins[:, 0, 2] += 0.5
        intrins[:, 1, 2] += 0.5
        uv_32 = self.get_ray(intrins, orig_H//32, orig_W//32, orig_H, orig_W, return_uv=True)
        uv_16 = self.get_ray(intrins, orig_H//16, orig_W//16, orig_H, orig_W, return_uv=True)
        uv_8 = self.get_ray(intrins, orig_H//8, orig_W//8, orig_H, orig_W, return_uv=True)
        ray_8 = self.get_ray(intrins, orig_H//8, orig_W//8, orig_H, orig_W)

        # Step 3. decoder - initial prediction
        pred_norm, feat_map, h = self.decoder(features, uvs=(uv_32, uv_16, uv_8))
        pred_norm = self.ray_relu(pred_norm, ray_8)

        # Step 4. add ray direction encoding
        feat_map = torch.cat([feat_map, uv_8], dim=1)

        # iterative refinement
        up_pred_norm = self.upsample(h, pred_norm, uv_8)
        pred_list = [up_pred_norm]
        for i in range(self.num_iter):
            h, pred_norm, up_pred_norm = self.refine(h, feat_map, 
                                                     pred_norm.detach(), 
                                                     intrins, orig_H, orig_W, uv_8, ray_8)
            pred_list.append(up_pred_norm)
        return pred_list