import warnings
import torch
from ..builder import DETECTORS
from .single_stage import SingleStageDetector
[docs]@DETECTORS.register_module()
class DETR(SingleStageDetector):
r"""Implementation of `DETR: End-to-End Object Detection with
Transformers <https://arxiv.org/pdf/2005.12872>`_"""
def __init__(self,
backbone,
bbox_head,
train_cfg=None,
test_cfg=None,
pretrained=None,
init_cfg=None):
super(DETR, self).__init__(backbone, None, bbox_head, train_cfg,
test_cfg, pretrained, init_cfg)
# over-write `forward_dummy` because:
# the forward of bbox_head requires img_metas
[docs] def forward_dummy(self, img):
"""Used for computing network flops.
See `mmdetection/tools/analysis_tools/get_flops.py`
"""
warnings.warn('Warning! MultiheadAttention in DETR does not '
'support flops computation! Do not use the '
'results in your papers!')
batch_size, _, height, width = img.shape
dummy_img_metas = [
dict(
batch_input_shape=(height, width),
img_shape=(height, width, 3)) for _ in range(batch_size)
]
x = self.extract_feat(img)
outs = self.bbox_head(x, dummy_img_metas)
return outs
# over-write `onnx_export` because:
# (1) the forward of bbox_head requires img_metas
# (2) the different behavior (e.g. construction of `masks`) between
# torch and ONNX model, during the forward of bbox_head
[docs] def onnx_export(self, img, img_metas):
"""Test function for exporting to ONNX, 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)
# forward of this head requires img_metas
outs = self.bbox_head.forward_onnx(x, img_metas)
# get shape as tensor
img_shape = torch._shape_as_tensor(img)[2:]
img_metas[0]['img_shape_for_onnx'] = img_shape
det_bboxes, det_labels = self.bbox_head.onnx_export(*outs, img_metas)
return det_bboxes, det_labels