mmocr/projects/ABCNet/abcnet/model/abcnet_det_module_loss.py

360 lines
15 KiB
Python

# Copyright (c) OpenMMLab. All rights reserved.
from typing import Dict, List, Tuple
import torch
from mmdet.models.task_modules.prior_generators import MlvlPointGenerator
from mmdet.models.utils import multi_apply
from mmdet.utils import reduce_mean
from torch import Tensor
from mmocr.models.textdet.module_losses.base import BaseTextDetModuleLoss
from mmocr.registry import MODELS, TASK_UTILS
from mmocr.structures import TextDetDataSample
from mmocr.utils import ConfigType, DetSampleList, RangeType
from ..utils import poly2bezier
INF = 1e8
@MODELS.register_module()
class ABCNetDetModuleLoss(BaseTextDetModuleLoss):
# TODO add docs
def __init__(
self,
num_classes: int = 1,
bbox_coder: ConfigType = dict(type='mmdet.DistancePointBBoxCoder'),
regress_ranges: RangeType = ((-1, 64), (64, 128), (128, 256),
(256, 512), (512, INF)),
strides: List[int] = (8, 16, 32, 64, 128),
center_sampling: bool = True,
center_sample_radius: float = 1.5,
norm_on_bbox: bool = True,
loss_cls: ConfigType = dict(
type='mmdet.FocalLoss',
use_sigmoid=True,
gamma=2.0,
alpha=0.25,
loss_weight=1.0),
loss_bbox: ConfigType = dict(type='mmdet.GIoULoss', loss_weight=1.0),
loss_centerness: ConfigType = dict(
type='mmdet.CrossEntropyLoss', use_sigmoid=True, loss_weight=1.0),
loss_bezier: ConfigType = dict(
type='mmdet.SmoothL1Loss', reduction='mean', loss_weight=1.0)
) -> None:
super().__init__()
self.num_classes = num_classes
self.strides = strides
self.prior_generator = MlvlPointGenerator(strides)
self.regress_ranges = regress_ranges
self.center_sampling = center_sampling
self.center_sample_radius = center_sample_radius
self.norm_on_bbox = norm_on_bbox
self.loss_centerness = MODELS.build(loss_centerness)
self.loss_cls = MODELS.build(loss_cls)
self.loss_bbox = MODELS.build(loss_bbox)
self.loss_bezier = MODELS.build(loss_bezier)
self.bbox_coder = TASK_UTILS.build(bbox_coder)
use_sigmoid_cls = loss_cls.get('use_sigmoid', False)
if use_sigmoid_cls:
self.cls_out_channels = num_classes
else:
self.cls_out_channels = num_classes + 1
def forward(self, inputs: Tuple[Tensor],
data_samples: DetSampleList) -> Dict:
"""Compute ABCNet loss.
Args:
inputs (tuple(tensor)): Raw predictions from model, containing
``cls_scores``, ``bbox_preds``, ``beizer_preds`` and
``centernesses``.
Each is a tensor of shape :math:`(N, H, W)`.
data_samples (list[TextDetDataSample]): The data samples.
Returns:
dict: The dict for abcnet-det losses with loss_cls, loss_bbox,
loss_centerness and loss_bezier.
"""
cls_scores, bbox_preds, centernesses, beizer_preds = inputs
assert len(cls_scores) == len(bbox_preds) == len(centernesses) == len(
beizer_preds)
featmap_sizes = [featmap.size()[-2:] for featmap in cls_scores]
all_level_points = self.prior_generator.grid_priors(
featmap_sizes,
dtype=bbox_preds[0].dtype,
device=bbox_preds[0].device)
labels, bbox_targets, bezier_targets = self.get_targets(
all_level_points, data_samples)
num_imgs = cls_scores[0].size(0)
# flatten cls_scores, bbox_preds and centerness
flatten_cls_scores = [
cls_score.permute(0, 2, 3, 1).reshape(-1, self.cls_out_channels)
for cls_score in cls_scores
]
flatten_bbox_preds = [
bbox_pred.permute(0, 2, 3, 1).reshape(-1, 4)
for bbox_pred in bbox_preds
]
flatten_centerness = [
centerness.permute(0, 2, 3, 1).reshape(-1)
for centerness in centernesses
]
flatten_bezier_preds = [
bezier_pred.permute(0, 2, 3, 1).reshape(-1, 16)
for bezier_pred in beizer_preds
]
flatten_cls_scores = torch.cat(flatten_cls_scores)
flatten_bbox_preds = torch.cat(flatten_bbox_preds)
flatten_centerness = torch.cat(flatten_centerness)
flatten_bezier_preds = torch.cat(flatten_bezier_preds)
flatten_labels = torch.cat(labels)
flatten_bbox_targets = torch.cat(bbox_targets)
flatten_bezier_targets = torch.cat(bezier_targets)
# repeat points to align with bbox_preds
flatten_points = torch.cat(
[points.repeat(num_imgs, 1) for points in all_level_points])
# FG cat_id: [0, num_classes -1], BG cat_id: num_classes
bg_class_ind = self.num_classes
pos_inds = ((flatten_labels >= 0)
& (flatten_labels < bg_class_ind)).nonzero().reshape(-1)
num_pos = torch.tensor(
len(pos_inds), dtype=torch.float, device=bbox_preds[0].device)
num_pos = max(reduce_mean(num_pos), 1.0)
loss_cls = self.loss_cls(
flatten_cls_scores, flatten_labels, avg_factor=num_pos)
pos_bbox_preds = flatten_bbox_preds[pos_inds]
pos_centerness = flatten_centerness[pos_inds]
pos_bezier_preds = flatten_bezier_preds[pos_inds]
pos_bbox_targets = flatten_bbox_targets[pos_inds]
pos_centerness_targets = self.centerness_target(pos_bbox_targets)
pos_bezier_targets = flatten_bezier_targets[pos_inds]
# centerness weighted iou loss
centerness_denorm = max(
reduce_mean(pos_centerness_targets.sum().detach()), 1e-6)
if len(pos_inds) > 0:
pos_points = flatten_points[pos_inds]
pos_decoded_bbox_preds = self.bbox_coder.decode(
pos_points, pos_bbox_preds)
pos_decoded_target_preds = self.bbox_coder.decode(
pos_points, pos_bbox_targets)
loss_bbox = self.loss_bbox(
pos_decoded_bbox_preds,
pos_decoded_target_preds,
weight=pos_centerness_targets,
avg_factor=centerness_denorm)
loss_centerness = self.loss_centerness(
pos_centerness, pos_centerness_targets, avg_factor=num_pos)
loss_bezier = self.loss_bezier(
pos_bezier_preds,
pos_bezier_targets,
weight=pos_centerness_targets[:, None],
avg_factor=centerness_denorm)
else:
loss_bbox = pos_bbox_preds.sum()
loss_centerness = pos_centerness.sum()
loss_bezier = pos_bezier_preds.sum()
return dict(
loss_cls=loss_cls,
loss_bbox=loss_bbox,
loss_centerness=loss_centerness,
loss_bezier=loss_bezier)
def get_targets(self, points: List[Tensor], data_samples: DetSampleList
) -> Tuple[List[Tensor], List[Tensor]]:
"""Compute regression, classification and centerness targets for points
in multiple images.
Args:
points (list[Tensor]): Points of each fpn level, each has shape
(num_points, 2).
data_samples: Batch of data samples. Each data sample contains
a gt_instance, which usually includes bboxes and labels
attributes.
Returns:
tuple: Targets of each level.
- concat_lvl_labels (list[Tensor]): Labels of each level.
- concat_lvl_bbox_targets (list[Tensor]): BBox targets of each \
level.
"""
assert len(points) == len(self.regress_ranges)
num_levels = len(points)
# expand regress ranges to align with points
expanded_regress_ranges = [
points[i].new_tensor(self.regress_ranges[i])[None].expand_as(
points[i]) for i in range(num_levels)
]
# concat all levels points and regress ranges
concat_regress_ranges = torch.cat(expanded_regress_ranges, dim=0)
concat_points = torch.cat(points, dim=0)
# the number of points per img, per lvl
num_points = [center.size(0) for center in points]
# get labels and bbox_targets of each image
labels_list, bbox_targets_list, bezier_targets_list = multi_apply(
self._get_targets_single,
data_samples,
points=concat_points,
regress_ranges=concat_regress_ranges,
num_points_per_lvl=num_points)
# split to per img, per level
labels_list = [labels.split(num_points, 0) for labels in labels_list]
bbox_targets_list = [
bbox_targets.split(num_points, 0)
for bbox_targets in bbox_targets_list
]
bezier_targets_list = [
bezier_targets.split(num_points, 0)
for bezier_targets in bezier_targets_list
]
# concat per level image
concat_lvl_labels = []
concat_lvl_bbox_targets = []
concat_lvl_bezier_targets = []
for i in range(num_levels):
concat_lvl_labels.append(
torch.cat([labels[i] for labels in labels_list]))
bbox_targets = torch.cat(
[bbox_targets[i] for bbox_targets in bbox_targets_list])
bezier_targets = torch.cat(
[bezier_targets[i] for bezier_targets in bezier_targets_list])
if self.norm_on_bbox:
bbox_targets = bbox_targets / self.strides[i]
bezier_targets = bezier_targets / self.strides[i]
concat_lvl_bbox_targets.append(bbox_targets)
concat_lvl_bezier_targets.append(bezier_targets)
return (concat_lvl_labels, concat_lvl_bbox_targets,
concat_lvl_bezier_targets)
def _get_targets_single(self, data_sample: TextDetDataSample,
points: Tensor, regress_ranges: Tensor,
num_points_per_lvl: List[int]
) -> Tuple[Tensor, Tensor, Tensor]:
"""Compute regression and classification targets for a single image."""
num_points = points.size(0)
gt_instances = data_sample.gt_instances
gt_instances = gt_instances[~gt_instances.ignored]
num_gts = len(gt_instances)
gt_bboxes = gt_instances.bboxes
gt_labels = gt_instances.labels
data_sample.gt_instances = gt_instances
polygons = gt_instances.polygons
beziers = gt_bboxes.new([poly2bezier(poly) for poly in polygons])
gt_instances.beziers = beziers
if num_gts == 0:
return gt_labels.new_full((num_points,), self.num_classes), \
gt_bboxes.new_zeros((num_points, 4)), \
gt_bboxes.new_zeros((num_points, 16))
areas = (gt_bboxes[:, 2] - gt_bboxes[:, 0]) * (
gt_bboxes[:, 3] - gt_bboxes[:, 1])
# TODO: figure out why these two are different
# areas = areas[None].expand(num_points, num_gts)
areas = areas[None].repeat(num_points, 1)
regress_ranges = regress_ranges[:, None, :].expand(
num_points, num_gts, 2)
gt_bboxes = gt_bboxes[None].expand(num_points, num_gts, 4)
xs, ys = points[:, 0], points[:, 1]
xs = xs[:, None].expand(num_points, num_gts)
ys = ys[:, None].expand(num_points, num_gts)
left = xs - gt_bboxes[..., 0]
right = gt_bboxes[..., 2] - xs
top = ys - gt_bboxes[..., 1]
bottom = gt_bboxes[..., 3] - ys
bbox_targets = torch.stack((left, top, right, bottom), -1)
beziers = beziers.reshape(-1, 8,
2)[None].expand(num_points, num_gts, 8, 2)
beziers_left = beziers[..., 0] - xs[..., None]
beziers_right = beziers[..., 1] - ys[..., None]
bezier_targets = torch.stack((beziers_left, beziers_right), dim=-1)
bezier_targets = bezier_targets.view(num_points, num_gts, 16)
if self.center_sampling:
# condition1: inside a `center bbox`
radius = self.center_sample_radius
center_xs = (gt_bboxes[..., 0] + gt_bboxes[..., 2]) / 2
center_ys = (gt_bboxes[..., 1] + gt_bboxes[..., 3]) / 2
center_gts = torch.zeros_like(gt_bboxes)
stride = center_xs.new_zeros(center_xs.shape)
# project the points on current lvl back to the `original` sizes
lvl_begin = 0
for lvl_idx, num_points_lvl in enumerate(num_points_per_lvl):
lvl_end = lvl_begin + num_points_lvl
stride[lvl_begin:lvl_end] = self.strides[lvl_idx] * radius
lvl_begin = lvl_end
x_mins = center_xs - stride
y_mins = center_ys - stride
x_maxs = center_xs + stride
y_maxs = center_ys + stride
center_gts[..., 0] = torch.where(x_mins > gt_bboxes[..., 0],
x_mins, gt_bboxes[..., 0])
center_gts[..., 1] = torch.where(y_mins > gt_bboxes[..., 1],
y_mins, gt_bboxes[..., 1])
center_gts[..., 2] = torch.where(x_maxs > gt_bboxes[..., 2],
gt_bboxes[..., 2], x_maxs)
center_gts[..., 3] = torch.where(y_maxs > gt_bboxes[..., 3],
gt_bboxes[..., 3], y_maxs)
cb_dist_left = xs - center_gts[..., 0]
cb_dist_right = center_gts[..., 2] - xs
cb_dist_top = ys - center_gts[..., 1]
cb_dist_bottom = center_gts[..., 3] - ys
center_bbox = torch.stack(
(cb_dist_left, cb_dist_top, cb_dist_right, cb_dist_bottom), -1)
inside_gt_bbox_mask = center_bbox.min(-1)[0] > 0
else:
# condition1: inside a gt bbox
inside_gt_bbox_mask = bbox_targets.min(-1)[0] > 0
# condition2: limit the regression range for each location
max_regress_distance = bbox_targets.max(-1)[0]
inside_regress_range = (
(max_regress_distance >= regress_ranges[..., 0])
& (max_regress_distance <= regress_ranges[..., 1]))
# if there are still more than one objects for a location,
# we choose the one with minimal area
areas[inside_gt_bbox_mask == 0] = INF
areas[inside_regress_range == 0] = INF
min_area, min_area_inds = areas.min(dim=1)
labels = gt_labels[min_area_inds]
labels[min_area == INF] = self.num_classes # set as BG
bbox_targets = bbox_targets[range(num_points), min_area_inds]
bezier_targets = bezier_targets[range(num_points), min_area_inds]
return labels, bbox_targets, bezier_targets
def centerness_target(self, pos_bbox_targets: Tensor) -> Tensor:
"""Compute centerness targets.
Args:
pos_bbox_targets (Tensor): BBox targets of positive bboxes in shape
(num_pos, 4)
Returns:
Tensor: Centerness target.
"""
# only calculate pos centerness targets, otherwise there may be nan
left_right = pos_bbox_targets[:, [0, 2]]
top_bottom = pos_bbox_targets[:, [1, 3]]
if len(left_right) == 0:
centerness_targets = left_right[..., 0]
else:
centerness_targets = (
left_right.min(dim=-1)[0] / left_right.max(dim=-1)[0]) * (
top_bottom.min(dim=-1)[0] / top_bottom.max(dim=-1)[0])
return torch.sqrt(centerness_targets)