Spaces:
Nymbo
/
Running on Zero

File size: 9,103 Bytes
938e515
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright (c) Facebook, Inc. and its affiliates.
import math
from typing import Any, List
import torch
from torch import nn
from torch.nn import functional as F

from detectron2.config import CfgNode
from detectron2.structures import Instances

from .. import DensePoseConfidenceModelConfig, DensePoseUVConfidenceType
from .chart import DensePoseChartLoss
from .registry import DENSEPOSE_LOSS_REGISTRY
from .utils import BilinearInterpolationHelper, LossDict


@DENSEPOSE_LOSS_REGISTRY.register()
class DensePoseChartWithConfidenceLoss(DensePoseChartLoss):
    """ """

    def __init__(self, cfg: CfgNode):
        super().__init__(cfg)
        self.confidence_model_cfg = DensePoseConfidenceModelConfig.from_cfg(cfg)
        if self.confidence_model_cfg.uv_confidence.type == DensePoseUVConfidenceType.IID_ISO:
            self.uv_loss_with_confidences = IIDIsotropicGaussianUVLoss(
                self.confidence_model_cfg.uv_confidence.epsilon
            )
        elif self.confidence_model_cfg.uv_confidence.type == DensePoseUVConfidenceType.INDEP_ANISO:
            self.uv_loss_with_confidences = IndepAnisotropicGaussianUVLoss(
                self.confidence_model_cfg.uv_confidence.epsilon
            )

    def produce_fake_densepose_losses_uv(self, densepose_predictor_outputs: Any) -> LossDict:
        """
        Overrides fake losses for fine segmentation and U/V coordinates to
        include computation graphs for additional confidence parameters.
        These are used when no suitable ground truth data was found in a batch.
        The loss has a value 0 and is primarily used to construct the computation graph,
        so that `DistributedDataParallel` has similar graphs on all GPUs and can
        perform reduction properly.

        Args:
            densepose_predictor_outputs: DensePose predictor outputs, an object
                of a dataclass that is assumed to have the following attributes:
             * fine_segm - fine segmentation estimates, tensor of shape [N, C, S, S]
             * u - U coordinate estimates per fine labels, tensor of shape [N, C, S, S]
             * v - V coordinate estimates per fine labels, tensor of shape [N, C, S, S]
        Return:
            dict: str -> tensor: dict of losses with the following entries:
             * `loss_densepose_U`: has value 0
             * `loss_densepose_V`: has value 0
             * `loss_densepose_I`: has value 0
        """
        conf_type = self.confidence_model_cfg.uv_confidence.type
        if self.confidence_model_cfg.uv_confidence.enabled:
            loss_uv = (
                densepose_predictor_outputs.u.sum() + densepose_predictor_outputs.v.sum()
            ) * 0
            if conf_type == DensePoseUVConfidenceType.IID_ISO:
                loss_uv += densepose_predictor_outputs.sigma_2.sum() * 0
            elif conf_type == DensePoseUVConfidenceType.INDEP_ANISO:
                loss_uv += (
                    densepose_predictor_outputs.sigma_2.sum()
                    + densepose_predictor_outputs.kappa_u.sum()
                    + densepose_predictor_outputs.kappa_v.sum()
                ) * 0
            return {"loss_densepose_UV": loss_uv}
        else:
            return super().produce_fake_densepose_losses_uv(densepose_predictor_outputs)

    def produce_densepose_losses_uv(
        self,
        proposals_with_gt: List[Instances],
        densepose_predictor_outputs: Any,
        packed_annotations: Any,
        interpolator: BilinearInterpolationHelper,
        j_valid_fg: torch.Tensor,
    ) -> LossDict:
        conf_type = self.confidence_model_cfg.uv_confidence.type
        if self.confidence_model_cfg.uv_confidence.enabled:
            u_gt = packed_annotations.u_gt[j_valid_fg]
            u_est = interpolator.extract_at_points(densepose_predictor_outputs.u)[j_valid_fg]
            v_gt = packed_annotations.v_gt[j_valid_fg]
            v_est = interpolator.extract_at_points(densepose_predictor_outputs.v)[j_valid_fg]
            sigma_2_est = interpolator.extract_at_points(densepose_predictor_outputs.sigma_2)[
                j_valid_fg
            ]
            if conf_type == DensePoseUVConfidenceType.IID_ISO:
                return {
                    "loss_densepose_UV": (
                        self.uv_loss_with_confidences(u_est, v_est, sigma_2_est, u_gt, v_gt)
                        * self.w_points
                    )
                }
            elif conf_type in [DensePoseUVConfidenceType.INDEP_ANISO]:
                kappa_u_est = interpolator.extract_at_points(densepose_predictor_outputs.kappa_u)[
                    j_valid_fg
                ]
                kappa_v_est = interpolator.extract_at_points(densepose_predictor_outputs.kappa_v)[
                    j_valid_fg
                ]
                return {
                    "loss_densepose_UV": (
                        self.uv_loss_with_confidences(
                            u_est, v_est, sigma_2_est, kappa_u_est, kappa_v_est, u_gt, v_gt
                        )
                        * self.w_points
                    )
                }
        return super().produce_densepose_losses_uv(
            proposals_with_gt,
            densepose_predictor_outputs,
            packed_annotations,
            interpolator,
            j_valid_fg,
        )


class IIDIsotropicGaussianUVLoss(nn.Module):
    """
    Loss for the case of iid residuals with isotropic covariance:
    $Sigma_i = sigma_i^2 I$
    The loss (negative log likelihood) is then:
    $1/2 sum_{i=1}^n (log(2 pi) + 2 log sigma_i^2 + ||delta_i||^2 / sigma_i^2)$,
    where $delta_i=(u - u', v - v')$ is a 2D vector containing UV coordinates
    difference between estimated and ground truth UV values
    For details, see:
    N. Neverova, D. Novotny, A. Vedaldi "Correlated Uncertainty for Learning
    Dense Correspondences from Noisy Labels", p. 918--926, in Proc. NIPS 2019
    """

    def __init__(self, sigma_lower_bound: float):
        super(IIDIsotropicGaussianUVLoss, self).__init__()
        self.sigma_lower_bound = sigma_lower_bound
        self.log2pi = math.log(2 * math.pi)

    def forward(
        self,
        u: torch.Tensor,
        v: torch.Tensor,
        sigma_u: torch.Tensor,
        target_u: torch.Tensor,
        target_v: torch.Tensor,
    ):
        # compute $\sigma_i^2$
        # use sigma_lower_bound to avoid degenerate solution for variance
        # (sigma -> 0)
        sigma2 = F.softplus(sigma_u) + self.sigma_lower_bound
        # compute \|delta_i\|^2
        # pyre-fixme[58]: `**` is not supported for operand types `Tensor` and `int`.
        delta_t_delta = (u - target_u) ** 2 + (v - target_v) ** 2
        # the total loss from the formula above:
        loss = 0.5 * (self.log2pi + 2 * torch.log(sigma2) + delta_t_delta / sigma2)
        return loss.sum()


class IndepAnisotropicGaussianUVLoss(nn.Module):
    """
    Loss for the case of independent residuals with anisotropic covariances:
    $Sigma_i = sigma_i^2 I + r_i r_i^T$
    The loss (negative log likelihood) is then:
    $1/2 sum_{i=1}^n (log(2 pi)
      + log sigma_i^2 (sigma_i^2 + ||r_i||^2)
      + ||delta_i||^2 / sigma_i^2
      - <delta_i, r_i>^2 / (sigma_i^2 * (sigma_i^2 + ||r_i||^2)))$,
    where $delta_i=(u - u', v - v')$ is a 2D vector containing UV coordinates
    difference between estimated and ground truth UV values
    For details, see:
    N. Neverova, D. Novotny, A. Vedaldi "Correlated Uncertainty for Learning
    Dense Correspondences from Noisy Labels", p. 918--926, in Proc. NIPS 2019
    """

    def __init__(self, sigma_lower_bound: float):
        super(IndepAnisotropicGaussianUVLoss, self).__init__()
        self.sigma_lower_bound = sigma_lower_bound
        self.log2pi = math.log(2 * math.pi)

    def forward(
        self,
        u: torch.Tensor,
        v: torch.Tensor,
        sigma_u: torch.Tensor,
        kappa_u_est: torch.Tensor,
        kappa_v_est: torch.Tensor,
        target_u: torch.Tensor,
        target_v: torch.Tensor,
    ):
        # compute $\sigma_i^2$
        sigma2 = F.softplus(sigma_u) + self.sigma_lower_bound
        # compute \|r_i\|^2
        # pyre-fixme[58]: `**` is not supported for operand types `Tensor` and `int`.
        r_sqnorm2 = kappa_u_est**2 + kappa_v_est**2
        delta_u = u - target_u
        delta_v = v - target_v
        # compute \|delta_i\|^2
        # pyre-fixme[58]: `**` is not supported for operand types `Tensor` and `int`.
        delta_sqnorm = delta_u**2 + delta_v**2
        delta_u_r_u = delta_u * kappa_u_est
        delta_v_r_v = delta_v * kappa_v_est
        # compute the scalar product <delta_i, r_i>
        delta_r = delta_u_r_u + delta_v_r_v
        # compute squared scalar product <delta_i, r_i>^2
        # pyre-fixme[58]: `**` is not supported for operand types `Tensor` and `int`.
        delta_r_sqnorm = delta_r**2
        denom2 = sigma2 * (sigma2 + r_sqnorm2)
        loss = 0.5 * (
            self.log2pi + torch.log(denom2) + delta_sqnorm / sigma2 - delta_r_sqnorm / denom2
        )
        return loss.sum()