File size: 5,114 Bytes
9bf4bd7
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright (c) OpenMMLab. All rights reserved.
from typing import Dict, Sequence, Tuple, Union

import torch
import torch.nn.functional as F

from mmocr.registry import MODELS
from mmocr.structures import TextDetDataSample
from . import PANModuleLoss


@MODELS.register_module()
class PSEModuleLoss(PANModuleLoss):
    """The class for implementing PSENet loss. This is partially adapted from
    https://github.com/whai362/PSENet.

    PSENet: `Shape Robust Text Detection with
    Progressive Scale Expansion Network <https://arxiv.org/abs/1806.02559>`_.

    Args:
        weight_text (float): The weight of text loss. Defaults to 0.7.
        weight_kernel (float): The weight of text kernel. Defaults to 0.3.
        loss_text (dict): Loss type for text. Defaults to
            dict('MaskedSquareDiceLoss').
        loss_kernel (dict): Loss type for kernel. Defaults to
            dict('MaskedSquareDiceLoss').
        ohem_ratio (int or float): The negative/positive ratio in ohem.
            Defaults to 3.
        reduction (str): The way to reduce the loss. Defaults to 'mean'.
            Options are 'mean' and 'sum'.
        kernel_sample_type (str): The way to sample kernel. Defaults to
            adaptive. Options are 'adaptive' and 'hard'.
        shrink_ratio (tuple): The ratio for shirinking text instances.
            Defaults to (1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4).
        max_shrink_dist (int or float): The maximum shrinking distance.
            Defaults to 20.
    """

    def __init__(
        self,
        weight_text: float = 0.7,
        weight_kernel: float = 0.3,
        loss_text: Dict = dict(type='MaskedSquareDiceLoss'),
        loss_kernel: Dict = dict(type='MaskedSquareDiceLoss'),
        ohem_ratio: Union[int, float] = 3,
        reduction: str = 'mean',
        kernel_sample_type: str = 'adaptive',
        shrink_ratio: Tuple[float] = (1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4),
        max_shrink_dist: Union[int, float] = 20,
    ) -> None:
        super().__init__()
        assert reduction in ['mean', 'sum'
                             ], "reduction must be either of ['mean','sum']"
        assert kernel_sample_type in [
            'adaptive', 'hard'
        ], "kernel_sample_type must be either of ['hard', 'adaptive']"
        self.weight_text = weight_text
        self.weight_kernel = weight_kernel
        self.ohem_ratio = ohem_ratio
        self.reduction = reduction
        self.shrink_ratio = shrink_ratio
        self.kernel_sample_type = kernel_sample_type
        self.max_shrink_dist = max_shrink_dist
        self.loss_text = MODELS.build(loss_text)
        self.loss_kernel = MODELS.build(loss_kernel)

    def forward(self, preds: torch.Tensor,
                data_samples: Sequence[TextDetDataSample]) -> Dict:
        """Compute PSENet loss.

        Args:
            preds (torch.Tensor): Raw predictions from model with
                shape :math:`(N, C, H, W)`.
            data_samples (list[TextDetDataSample]): The data samples.

        Returns:
            dict: The dict for pse losses with loss_text, loss_kernel,
            loss_aggregation and loss_discrimination.
        """
        losses = []

        gt_kernels, gt_masks = self.get_targets(data_samples)
        target_size = gt_kernels.size()[2:]
        preds = F.interpolate(preds, size=target_size, mode='bilinear')
        pred_texts = preds[:, 0, :, :]
        pred_kernels = preds[:, 1:, :, :]

        gt_kernels = gt_kernels.to(preds.device)
        gt_kernels[gt_kernels <= 0.5] = 0
        gt_kernels[gt_kernels > 0.5] = 1
        gt_masks = gt_masks.to(preds.device)

        # compute text loss
        sampled_mask = self._ohem_batch(pred_texts.detach(), gt_kernels[0],
                                        gt_masks)
        loss_texts = self.loss_text(pred_texts.sigmoid(), gt_kernels[0],
                                    sampled_mask)
        losses.append(self.weight_text * loss_texts)

        # compute kernel loss
        if self.kernel_sample_type == 'hard':
            sampled_masks_kernel = (gt_kernels[0] >
                                    0.5).float() * gt_masks.float()
        elif self.kernel_sample_type == 'adaptive':
            sampled_masks_kernel = (pred_texts > 0).float() * (
                gt_masks.float())
        else:
            raise NotImplementedError

        num_kernel = pred_kernels.shape[1]
        assert num_kernel == len(gt_kernels) - 1
        loss_list = []
        for idx in range(num_kernel):
            loss_kernels = self.loss_kernel(
                pred_kernels[:, idx, :, :].sigmoid(), gt_kernels[1 + idx],
                sampled_masks_kernel)
            loss_list.append(loss_kernels)

        losses.append(self.weight_kernel * sum(loss_list) / len(loss_list))

        if self.reduction == 'mean':
            losses = [item.mean() for item in losses]
        elif self.reduction == 'sum':
            losses = [item.sum() for item in losses]
        else:
            raise NotImplementedError

        results = dict(loss_text=losses[0], loss_kernel=losses[1])
        return results