import warnings
import torch
from mmdet.core import bbox2result
from ..builder import DETECTORS, build_backbone, build_head, build_neck
from .base import BaseDetector
[docs]@DETECTORS.register_module()
class SingleStageDetector(BaseDetector):
"""Base class for single-stage detectors.
Single-stage detectors directly and densely predict bounding boxes on the
output features of the backbone+neck.
"""
def __init__(self,
backbone,
neck=None,
bbox_head=None,
train_cfg=None,
test_cfg=None,
pretrained=None,
init_cfg=None):
super(SingleStageDetector, self).__init__(init_cfg)
if pretrained:
warnings.warn('DeprecationWarning: pretrained is deprecated, '
'please use "init_cfg" instead')
backbone.pretrained = pretrained
self.backbone = build_backbone(backbone)
if neck is not None:
self.neck = build_neck(neck)
bbox_head.update(train_cfg=train_cfg)
bbox_head.update(test_cfg=test_cfg)
self.bbox_head = build_head(bbox_head)
self.train_cfg = train_cfg
self.test_cfg = test_cfg
[docs] def forward_dummy(self, img):
"""Used for computing network flops.
See `mmdetection/tools/analysis_tools/get_flops.py`
"""
x = self.extract_feat(img)
outs = self.bbox_head(x)
return outs
[docs] def forward_train(self,
img,
img_metas,
gt_bboxes,
gt_labels,
gt_bboxes_ignore=None):
"""
Args:
img (Tensor): Input images of shape (N, C, H, W).
Typically these should be mean centered and std scaled.
img_metas (list[dict]): A List of image info dict where each dict
has: 'img_shape', 'scale_factor', 'flip', and may also contain
'filename', 'ori_shape', 'pad_shape', and 'img_norm_cfg'.
For details on the values of these keys see
:class:`mmdet.datasets.pipelines.Collect`.
gt_bboxes (list[Tensor]): Each item are the truth boxes for each
image in [tl_x, tl_y, br_x, br_y] format.
gt_labels (list[Tensor]): Class indices corresponding to each box
gt_bboxes_ignore (None | list[Tensor]): Specify which bounding
boxes can be ignored when computing the loss.
Returns:
dict[str, Tensor]: A dictionary of loss components.
"""
super(SingleStageDetector, self).forward_train(img, img_metas)
x = self.extract_feat(img)
losses = self.bbox_head.forward_train(x, img_metas, gt_bboxes,
gt_labels, gt_bboxes_ignore)
return losses
[docs] def simple_test(self, img, img_metas, rescale=False):
"""Test function without test-time augmentation.
Args:
img (torch.Tensor): Images with shape (N, C, H, W).
img_metas (list[dict]): List of image information.
rescale (bool, optional): Whether to rescale the results.
Defaults to False.
Returns:
list[list[np.ndarray]]: BBox results of each image and classes.
The outer list corresponds to each image. The inner list
corresponds to each class.
"""
feat = self.extract_feat(img)
results_list = self.bbox_head.simple_test(
feat, img_metas, rescale=rescale)
bbox_results = [
bbox2result(det_bboxes, det_labels, self.bbox_head.num_classes)
for det_bboxes, det_labels in results_list
]
return bbox_results
[docs] def aug_test(self, imgs, img_metas, rescale=False):
"""Test function with test time augmentation.
Args:
imgs (list[Tensor]): the outer list indicates test-time
augmentations and inner Tensor should have a shape NxCxHxW,
which contains all images in the batch.
img_metas (list[list[dict]]): the outer list indicates test-time
augs (multiscale, flip, etc.) and the inner list indicates
images in a batch. each dict has image information.
rescale (bool, optional): Whether to rescale the results.
Defaults to False.
Returns:
list[list[np.ndarray]]: BBox results of each image and classes.
The outer list corresponds to each image. The inner list
corresponds to each class.
"""
assert hasattr(self.bbox_head, 'aug_test'), \
f'{self.bbox_head.__class__.__name__}' \
' does not support test-time augmentation'
feats = self.extract_feats(imgs)
results_list = self.bbox_head.aug_test(
feats, img_metas, rescale=rescale)
bbox_results = [
bbox2result(det_bboxes, det_labels, self.bbox_head.num_classes)
for det_bboxes, det_labels in results_list
]
return bbox_results
[docs] def onnx_export(self, img, img_metas):
"""Test function without test time augmentation.
Args:
img (torch.Tensor): input images.
img_metas (list[dict]): List of image information.
Returns:
tuple[Tensor, Tensor]: dets of shape [N, num_det, 5]
and class labels of shape [N, num_det].
"""
x = self.extract_feat(img)
outs = self.bbox_head(x)
# get origin input shape to support onnx dynamic shape
# get shape as tensor
img_shape = torch._shape_as_tensor(img)[2:]
img_metas[0]['img_shape_for_onnx'] = img_shape
# get pad input shape to support onnx dynamic shape for exporting
# `CornerNet` and `CentripetalNet`, which 'pad_shape' is used
# for inference
img_metas[0]['pad_shape_for_onnx'] = img_shape
# TODO:move all onnx related code in bbox_head to onnx_export function
det_bboxes, det_labels = self.bbox_head.get_bboxes(*outs, img_metas)
return det_bboxes, det_labels