import mmcv
from mmdet.core import bbox_mapping, tensor2imgs
from ..builder import DETECTORS, build_backbone, build_head, build_neck
from .base import BaseDetector
from .test_mixins import RPNTestMixin
[docs]@DETECTORS.register_module()
class RPN(BaseDetector, RPNTestMixin):
def __init__(self,
backbone,
neck,
rpn_head,
train_cfg,
test_cfg,
pretrained=None):
super(RPN, self).__init__()
self.backbone = build_backbone(backbone)
self.neck = build_neck(neck) if neck is not None else None
rpn_train_cfg = train_cfg.rpn if train_cfg is not None else None
rpn_head.update(train_cfg=rpn_train_cfg)
rpn_head.update(test_cfg=test_cfg.rpn)
self.rpn_head = build_head(rpn_head)
self.train_cfg = train_cfg
self.test_cfg = test_cfg
self.init_weights(pretrained=pretrained)
def init_weights(self, pretrained=None):
super(RPN, self).init_weights(pretrained)
self.backbone.init_weights(pretrained=pretrained)
if self.with_neck:
self.neck.init_weights()
self.rpn_head.init_weights()
def extract_feat(self, img):
x = self.backbone(img)
if self.with_neck:
x = self.neck(x)
return x
def forward_dummy(self, img):
x = self.extract_feat(img)
rpn_outs = self.rpn_head(x)
return rpn_outs
[docs] def forward_train(self,
img,
img_metas,
gt_bboxes=None,
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_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.
"""
if self.train_cfg.rpn.get('debug', False):
self.rpn_head.debug_imgs = tensor2imgs(img)
x = self.extract_feat(img)
rpn_outs = self.rpn_head(x)
rpn_loss_inputs = rpn_outs + (gt_bboxes, img_metas)
losses = self.rpn_head.loss(
*rpn_loss_inputs, gt_bboxes_ignore=gt_bboxes_ignore)
return losses
def simple_test(self, img, img_metas, rescale=False):
x = self.extract_feat(img)
proposal_list = self.simple_test_rpn(x, img_metas)
if rescale:
for proposals, meta in zip(proposal_list, img_metas):
proposals[:, :4] /= proposals.new_tensor(meta['scale_factor'])
# TODO: remove this restriction
return proposal_list[0].cpu().numpy()
def aug_test(self, imgs, img_metas, rescale=False):
proposal_list = self.aug_test_rpn(
self.extract_feats(imgs), img_metas, self.test_cfg.rpn)
if not rescale:
for proposals, img_meta in zip(proposal_list, img_metas[0]):
img_shape = img_meta['img_shape']
scale_factor = img_meta['scale_factor']
flip = img_meta['flip']
flip_direction = img_meta['flip_direction']
proposals[:, :4] = bbox_mapping(proposals[:, :4], img_shape,
scale_factor, flip,
flip_direction)
# TODO: remove this restriction
return proposal_list[0].cpu().numpy()
[docs] def show_result(self, data, result, dataset=None, top_k=20):
"""Show RPN proposals on the image.
Although we assume batch size is 1, this method supports arbitrary
batch size.
"""
img_tensor = data['img'][0]
img_metas = data['img_metas'][0].data[0]
imgs = tensor2imgs(img_tensor, **img_metas[0]['img_norm_cfg'])
assert len(imgs) == len(img_metas)
for img, img_meta in zip(imgs, img_metas):
h, w, _ = img_meta['img_shape']
img_show = img[:h, :w, :]
mmcv.imshow_bboxes(img_show, result, top_k=top_k)