File size: 9,433 Bytes
01664b3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
241
242
243
244
# Copyright (c) Facebook, Inc. and its affiliates.
import logging
from typing import Callable, Dict, List, Optional, Tuple, Union

import fvcore.nn.weight_init as weight_init
from torch import nn
from torch.nn import functional as F

from detectron2.config import configurable
from detectron2.layers import Conv2d, ShapeSpec, get_norm
from detectron2.modeling import SEM_SEG_HEADS_REGISTRY

from ..transformer_decoder.maskformer_transformer_decoder import StandardTransformerDecoder
from ..pixel_decoder.fpn import build_pixel_decoder


@SEM_SEG_HEADS_REGISTRY.register()
class PerPixelBaselineHead(nn.Module):

    _version = 2

    def _load_from_state_dict(
        self, state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs
    ):
        version = local_metadata.get("version", None)
        if version is None or version < 2:
            logger = logging.getLogger(__name__)
            # Do not warn if train from scratch
            scratch = True
            logger = logging.getLogger(__name__)
            for k in list(state_dict.keys()):
                newk = k
                if "sem_seg_head" in k and not k.startswith(prefix + "predictor"):
                    newk = k.replace(prefix, prefix + "pixel_decoder.")
                    # logger.warning(f"{k} ==> {newk}")
                if newk != k:
                    state_dict[newk] = state_dict[k]
                    del state_dict[k]
                    scratch = False

            if not scratch:
                logger.warning(
                    f"Weight format of {self.__class__.__name__} have changed! "
                    "Please upgrade your models. Applying automatic conversion now ..."
                )

    @configurable
    def __init__(
        self,
        input_shape: Dict[str, ShapeSpec],
        *,
        num_classes: int,
        pixel_decoder: nn.Module,
        loss_weight: float = 1.0,
        ignore_value: int = -1,
    ):
        """
        NOTE: this interface is experimental.
        Args:
            input_shape: shapes (channels and stride) of the input features
            num_classes: number of classes to predict
            pixel_decoder: the pixel decoder module
            loss_weight: loss weight
            ignore_value: category id to be ignored during training.
        """
        super().__init__()
        input_shape = sorted(input_shape.items(), key=lambda x: x[1].stride)
        self.in_features = [k for k, v in input_shape]
        feature_strides = [v.stride for k, v in input_shape]
        feature_channels = [v.channels for k, v in input_shape]

        self.ignore_value = ignore_value
        self.common_stride = 4
        self.loss_weight = loss_weight

        self.pixel_decoder = pixel_decoder
        self.predictor = Conv2d(
            self.pixel_decoder.mask_dim, num_classes, kernel_size=1, stride=1, padding=0
        )
        weight_init.c2_msra_fill(self.predictor)

    @classmethod
    def from_config(cls, cfg, input_shape: Dict[str, ShapeSpec]):
        return {
            "input_shape": {
                k: v for k, v in input_shape.items() if k in cfg.MODEL.SEM_SEG_HEAD.IN_FEATURES
            },
            "ignore_value": cfg.MODEL.SEM_SEG_HEAD.IGNORE_VALUE,
            "num_classes": cfg.MODEL.SEM_SEG_HEAD.NUM_CLASSES,
            "pixel_decoder": build_pixel_decoder(cfg, input_shape),
            "loss_weight": cfg.MODEL.SEM_SEG_HEAD.LOSS_WEIGHT,
        }

    def forward(self, features, targets=None):
        """
        Returns:
            In training, returns (None, dict of losses)
            In inference, returns (CxHxW logits, {})
        """
        x = self.layers(features)
        if self.training:
            return None, self.losses(x, targets)
        else:
            x = F.interpolate(
                x, scale_factor=self.common_stride, mode="bilinear", align_corners=False
            )
            return x, {}

    def layers(self, features):
        x, _, _ = self.pixel_decoder.forward_features(features)
        x = self.predictor(x)
        return x

    def losses(self, predictions, targets):
        predictions = predictions.float()  # https://github.com/pytorch/pytorch/issues/48163
        predictions = F.interpolate(
            predictions, scale_factor=self.common_stride, mode="bilinear", align_corners=False
        )
        loss = F.cross_entropy(
            predictions, targets, reduction="mean", ignore_index=self.ignore_value
        )
        losses = {"loss_sem_seg": loss * self.loss_weight}
        return losses


@SEM_SEG_HEADS_REGISTRY.register()
class PerPixelBaselinePlusHead(PerPixelBaselineHead):
    def _load_from_state_dict(
        self, state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs
    ):
        version = local_metadata.get("version", None)
        if version is None or version < 2:
            # Do not warn if train from scratch
            scratch = True
            logger = logging.getLogger(__name__)
            for k in list(state_dict.keys()):
                newk = k
                if "sem_seg_head" in k and not k.startswith(prefix + "predictor"):
                    newk = k.replace(prefix, prefix + "pixel_decoder.")
                    logger.debug(f"{k} ==> {newk}")
                if newk != k:
                    state_dict[newk] = state_dict[k]
                    del state_dict[k]
                    scratch = False

            if not scratch:
                logger.warning(
                    f"Weight format of {self.__class__.__name__} have changed! "
                    "Please upgrade your models. Applying automatic conversion now ..."
                )

    @configurable
    def __init__(
        self,
        input_shape: Dict[str, ShapeSpec],
        *,
        # extra parameters
        transformer_predictor: nn.Module,
        transformer_in_feature: str,
        deep_supervision: bool,
        # inherit parameters
        num_classes: int,
        pixel_decoder: nn.Module,
        loss_weight: float = 1.0,
        ignore_value: int = -1,
    ):
        """
        NOTE: this interface is experimental.
        Args:
            input_shape: shapes (channels and stride) of the input features
            transformer_predictor: the transformer decoder that makes prediction
            transformer_in_feature: input feature name to the transformer_predictor
            deep_supervision: whether or not to add supervision to the output of
                every transformer decoder layer
            num_classes: number of classes to predict
            pixel_decoder: the pixel decoder module
            loss_weight: loss weight
            ignore_value: category id to be ignored during training.
        """
        super().__init__(
            input_shape,
            num_classes=num_classes,
            pixel_decoder=pixel_decoder,
            loss_weight=loss_weight,
            ignore_value=ignore_value,
        )

        del self.predictor

        self.predictor = transformer_predictor
        self.transformer_in_feature = transformer_in_feature
        self.deep_supervision = deep_supervision

    @classmethod
    def from_config(cls, cfg, input_shape: Dict[str, ShapeSpec]):
        ret = super().from_config(cfg, input_shape)
        ret["transformer_in_feature"] = cfg.MODEL.MASK_FORMER.TRANSFORMER_IN_FEATURE
        if cfg.MODEL.MASK_FORMER.TRANSFORMER_IN_FEATURE == "transformer_encoder":
            in_channels = cfg.MODEL.SEM_SEG_HEAD.CONVS_DIM
        else:
            in_channels = input_shape[ret["transformer_in_feature"]].channels
        ret["transformer_predictor"] = StandardTransformerDecoder(
            cfg, in_channels, mask_classification=False
        )
        ret["deep_supervision"] = cfg.MODEL.MASK_FORMER.DEEP_SUPERVISION
        return ret

    def forward(self, features, targets=None):
        """
        Returns:
            In training, returns (None, dict of losses)
            In inference, returns (CxHxW logits, {})
        """
        x, aux_outputs = self.layers(features)
        if self.training:
            if self.deep_supervision:
                losses = self.losses(x, targets)
                for i, aux_output in enumerate(aux_outputs):
                    losses["loss_sem_seg" + f"_{i}"] = self.losses(
                        aux_output["pred_masks"], targets
                    )["loss_sem_seg"]
                return None, losses
            else:
                return None, self.losses(x, targets)
        else:
            x = F.interpolate(
                x, scale_factor=self.common_stride, mode="bilinear", align_corners=False
            )
            return x, {}

    def layers(self, features):
        mask_features, transformer_encoder_features, _ = self.pixel_decoder.forward_features(features)
        if self.transformer_in_feature == "transformer_encoder":
            assert (
                transformer_encoder_features is not None
            ), "Please use the TransformerEncoderPixelDecoder."
            predictions = self.predictor(transformer_encoder_features, mask_features)
        else:
            predictions = self.predictor(features[self.transformer_in_feature], mask_features)
        if self.deep_supervision:
            return predictions["pred_masks"], predictions["aux_outputs"]
        else:
            return predictions["pred_masks"], None