from __future__ import division import torch import torch.nn as nn from mmdet.core import (bbox2result, bbox2roi, bbox_mapping, build_assigner, build_sampler, merge_aug_bboxes, merge_aug_masks, multiclass_nms) from .. import builder from ..registry import DETECTORS from .base import BaseDetector from .test_mixins import RPNTestMixin @DETECTORS.register_module class CascadeRCNN(BaseDetector, RPNTestMixin): def __init__(self, num_stages, backbone, neck=None, shared_head=None, rpn_head=None, bbox_roi_extractor=None, bbox_head=None, mask_roi_extractor=None, mask_head=None, train_cfg=None, test_cfg=None, pretrained=None): assert bbox_roi_extractor is not None assert bbox_head is not None super(CascadeRCNN, self).__init__() self.num_stages = num_stages self.backbone = builder.build_backbone(backbone) if neck is not None: self.neck = builder.build_neck(neck) if rpn_head is not None: self.rpn_head = builder.build_head(rpn_head) if shared_head is not None: self.shared_head = builder.build_shared_head(shared_head) if bbox_head is not None: self.bbox_roi_extractor = nn.ModuleList() self.bbox_head = nn.ModuleList() if not isinstance(bbox_roi_extractor, list): bbox_roi_extractor = [ bbox_roi_extractor for _ in range(num_stages) ] if not isinstance(bbox_head, list): bbox_head = [bbox_head for _ in range(num_stages)] assert len(bbox_roi_extractor) == len(bbox_head) == self.num_stages for roi_extractor, head in zip(bbox_roi_extractor, bbox_head): self.bbox_roi_extractor.append( builder.build_roi_extractor(roi_extractor)) self.bbox_head.append(builder.build_head(head)) if mask_head is not None: self.mask_head = nn.ModuleList() if not isinstance(mask_head, list): mask_head = [mask_head for _ in range(num_stages)] assert len(mask_head) == self.num_stages for head in mask_head: self.mask_head.append(builder.build_head(head)) if mask_roi_extractor is not None: self.share_roi_extractor = False self.mask_roi_extractor = nn.ModuleList() if not isinstance(mask_roi_extractor, list): mask_roi_extractor = [ mask_roi_extractor for _ in range(num_stages) ] assert len(mask_roi_extractor) == self.num_stages for roi_extractor in mask_roi_extractor: self.mask_roi_extractor.append( builder.build_roi_extractor(roi_extractor)) else: self.share_roi_extractor = True self.mask_roi_extractor = self.bbox_roi_extractor self.train_cfg = train_cfg self.test_cfg = test_cfg self.init_weights(pretrained=pretrained) @property def with_rpn(self): return hasattr(self, 'rpn_head') and self.rpn_head is not None def init_weights(self, pretrained=None): super(CascadeRCNN, self).init_weights(pretrained) self.backbone.init_weights(pretrained=pretrained) if self.with_neck: if isinstance(self.neck, nn.Sequential): for m in self.neck: m.init_weights() else: self.neck.init_weights() if self.with_rpn: self.rpn_head.init_weights() if self.with_shared_head: self.shared_head.init_weights(pretrained=pretrained) for i in range(self.num_stages): if self.with_bbox: self.bbox_roi_extractor[i].init_weights() self.bbox_head[i].init_weights() if self.with_mask: if not self.share_roi_extractor: self.mask_roi_extractor[i].init_weights() self.mask_head[i].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): outs = () # backbone x = self.extract_feat(img) # rpn if self.with_rpn: rpn_outs = self.rpn_head(x) outs = outs + (rpn_outs, ) proposals = torch.randn(1000, 4).cuda() # bbox heads rois = bbox2roi([proposals]) if self.with_bbox: for i in range(self.num_stages): bbox_feats = self.bbox_roi_extractor[i]( x[:self.bbox_roi_extractor[i].num_inputs], rois) if self.with_shared_head: bbox_feats = self.shared_head(bbox_feats) cls_score, bbox_pred = self.bbox_head[i](bbox_feats) outs = outs + (cls_score, bbox_pred) # mask heads if self.with_mask: mask_rois = rois[:100] for i in range(self.num_stages): mask_feats = self.mask_roi_extractor[i]( x[:self.mask_roi_extractor[i].num_inputs], mask_rois) if self.with_shared_head: mask_feats = self.shared_head(mask_feats) mask_pred = self.mask_head[i](mask_feats) outs = outs + (mask_pred, ) return outs def forward_train(self, img, img_meta, gt_bboxes, gt_labels, gt_bboxes_ignore=None, gt_masks=None, proposals=None): """ Args: img (Tensor): of shape (N, C, H, W) encoding input images. Typically these should be mean centered and std scaled. img_meta (list[dict]): list of image info dict where each dict has: 'img_shape', 'scale_factor', 'flip', and my also contain 'filename', 'ori_shape', 'pad_shape', and 'img_norm_cfg'. For details on the values of these keys see `mmdet/datasets/pipelines/formatting.py: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. gt_masks (None | Tensor) : true segmentation masks for each box used if the architecture supports a segmentation task. proposals : override rpn proposals with custom proposals. Use when `with_rpn` is False. Returns: dict[str, Tensor]: a dictionary of loss components """ x = self.extract_feat(img) losses = dict() if self.with_rpn: rpn_outs = self.rpn_head(x) rpn_loss_inputs = rpn_outs + (gt_bboxes, img_meta, self.train_cfg.rpn) rpn_losses = self.rpn_head.loss( *rpn_loss_inputs, gt_bboxes_ignore=gt_bboxes_ignore) losses.update(rpn_losses) proposal_cfg = self.train_cfg.get('rpn_proposal', self.test_cfg.rpn) proposal_inputs = rpn_outs + (img_meta, proposal_cfg) proposal_list = self.rpn_head.get_bboxes(*proposal_inputs) else: proposal_list = proposals for i in range(self.num_stages): self.current_stage = i rcnn_train_cfg = self.train_cfg.rcnn[i] lw = self.train_cfg.stage_loss_weights[i] # assign gts and sample proposals sampling_results = [] if self.with_bbox or self.with_mask: bbox_assigner = build_assigner(rcnn_train_cfg.assigner) bbox_sampler = build_sampler( rcnn_train_cfg.sampler, context=self) num_imgs = img.size(0) if gt_bboxes_ignore is None: gt_bboxes_ignore = [None for _ in range(num_imgs)] for j in range(num_imgs): assign_result = bbox_assigner.assign( proposal_list[j], gt_bboxes[j], gt_bboxes_ignore[j], gt_labels[j]) sampling_result = bbox_sampler.sample( assign_result, proposal_list[j], gt_bboxes[j], gt_labels[j], feats=[lvl_feat[j][None] for lvl_feat in x]) sampling_results.append(sampling_result) # bbox head forward and loss bbox_roi_extractor = self.bbox_roi_extractor[i] bbox_head = self.bbox_head[i] rois = bbox2roi([res.bboxes for res in sampling_results]) if len(rois) == 0: # If there are no predicted and/or truth boxes, then we cannot # compute head / mask losses continue bbox_feats = bbox_roi_extractor(x[:bbox_roi_extractor.num_inputs], rois) if self.with_shared_head: bbox_feats = self.shared_head(bbox_feats) cls_score, bbox_pred = bbox_head(bbox_feats) bbox_targets = bbox_head.get_target(sampling_results, gt_bboxes, gt_labels, rcnn_train_cfg) loss_bbox = bbox_head.loss(cls_score, bbox_pred, *bbox_targets) for name, value in loss_bbox.items(): losses['s{}.{}'.format(i, name)] = ( value * lw if 'loss' in name else value) # mask head forward and loss if self.with_mask: if not self.share_roi_extractor: mask_roi_extractor = self.mask_roi_extractor[i] pos_rois = bbox2roi( [res.pos_bboxes for res in sampling_results]) mask_feats = mask_roi_extractor( x[:mask_roi_extractor.num_inputs], pos_rois) if self.with_shared_head: mask_feats = self.shared_head(mask_feats) else: # reuse positive bbox feats pos_inds = [] device = bbox_feats.device for res in sampling_results: pos_inds.append( torch.ones( res.pos_bboxes.shape[0], device=device, dtype=torch.uint8)) pos_inds.append( torch.zeros( res.neg_bboxes.shape[0], device=device, dtype=torch.uint8)) pos_inds = torch.cat(pos_inds) mask_feats = bbox_feats[pos_inds] mask_head = self.mask_head[i] mask_pred = mask_head(mask_feats) mask_targets = mask_head.get_target(sampling_results, gt_masks, rcnn_train_cfg) pos_labels = torch.cat( [res.pos_gt_labels for res in sampling_results]) loss_mask = mask_head.loss(mask_pred, mask_targets, pos_labels) for name, value in loss_mask.items(): losses['s{}.{}'.format(i, name)] = ( value * lw if 'loss' in name else value) # refine bboxes if i < self.num_stages - 1: pos_is_gts = [res.pos_is_gt for res in sampling_results] roi_labels = bbox_targets[0] # bbox_targets is a tuple with torch.no_grad(): proposal_list = bbox_head.refine_bboxes( rois, roi_labels, bbox_pred, pos_is_gts, img_meta) return losses def simple_test(self, img, img_meta, proposals=None, rescale=False): """Run inference on a single image. Args: img (Tensor): must be in shape (N, C, H, W) img_meta (list[dict]): a list with one dictionary element. See `mmdet/datasets/pipelines/formatting.py:Collect` for details of meta dicts. proposals : if specified overrides rpn proposals rescale (bool): if True returns boxes in original image space Returns: dict: results """ x = self.extract_feat(img) proposal_list = self.simple_test_rpn( x, img_meta, self.test_cfg.rpn) if proposals is None else proposals img_shape = img_meta[0]['img_shape'] ori_shape = img_meta[0]['ori_shape'] scale_factor = img_meta[0]['scale_factor'] # "ms" in variable names means multi-stage ms_bbox_result = {} ms_segm_result = {} ms_scores = [] rcnn_test_cfg = self.test_cfg.rcnn rois = bbox2roi(proposal_list) for i in range(self.num_stages): bbox_roi_extractor = self.bbox_roi_extractor[i] bbox_head = self.bbox_head[i] bbox_feats = bbox_roi_extractor( x[:len(bbox_roi_extractor.featmap_strides)], rois) if self.with_shared_head: bbox_feats = self.shared_head(bbox_feats) cls_score, bbox_pred = bbox_head(bbox_feats) ms_scores.append(cls_score) if i < self.num_stages - 1: bbox_label = cls_score.argmax(dim=1) rois = bbox_head.regress_by_class(rois, bbox_label, bbox_pred, img_meta[0]) cls_score = sum(ms_scores) / self.num_stages det_bboxes, det_labels = self.bbox_head[-1].get_det_bboxes( rois, cls_score, bbox_pred, img_shape, scale_factor, rescale=rescale, cfg=rcnn_test_cfg) bbox_result = bbox2result(det_bboxes, det_labels, self.bbox_head[-1].num_classes) ms_bbox_result['ensemble'] = bbox_result if self.with_mask: if det_bboxes.shape[0] == 0: mask_classes = self.mask_head[-1].num_classes - 1 segm_result = [[] for _ in range(mask_classes)] else: if isinstance(scale_factor, float): # aspect ratio fixed _bboxes = ( det_bboxes[:, :4] * scale_factor if rescale else det_bboxes) else: _bboxes = ( det_bboxes[:, :4] * torch.from_numpy(scale_factor).to(det_bboxes.device) if rescale else det_bboxes) mask_rois = bbox2roi([_bboxes]) aug_masks = [] for i in range(self.num_stages): mask_roi_extractor = self.mask_roi_extractor[i] mask_feats = mask_roi_extractor( x[:len(mask_roi_extractor.featmap_strides)], mask_rois) if self.with_shared_head: mask_feats = self.shared_head(mask_feats) mask_pred = self.mask_head[i](mask_feats) aug_masks.append(mask_pred.sigmoid().cpu().numpy()) merged_masks = merge_aug_masks(aug_masks, [img_meta] * self.num_stages, self.test_cfg.rcnn) segm_result = self.mask_head[-1].get_seg_masks( merged_masks, _bboxes, det_labels, rcnn_test_cfg, ori_shape, scale_factor, rescale) ms_segm_result['ensemble'] = segm_result if self.with_mask: results = (ms_bbox_result['ensemble'], ms_segm_result['ensemble']) else: results = ms_bbox_result['ensemble'] return results def aug_test(self, imgs, img_metas, proposals=None, rescale=False): """Test with augmentations. If rescale is False, then returned bboxes and masks will fit the scale of imgs[0]. """ # recompute feats to save memory proposal_list = self.aug_test_rpn( self.extract_feats(imgs), img_metas, self.test_cfg.rpn) rcnn_test_cfg = self.test_cfg.rcnn aug_bboxes = [] aug_scores = [] for x, img_meta in zip(self.extract_feats(imgs), img_metas): # only one image in the batch img_shape = img_meta[0]['img_shape'] scale_factor = img_meta[0]['scale_factor'] flip = img_meta[0]['flip'] proposals = bbox_mapping(proposal_list[0][:, :4], img_shape, scale_factor, flip) # "ms" in variable names means multi-stage ms_scores = [] rois = bbox2roi([proposals]) for i in range(self.num_stages): bbox_roi_extractor = self.bbox_roi_extractor[i] bbox_head = self.bbox_head[i] bbox_feats = bbox_roi_extractor( x[:len(bbox_roi_extractor.featmap_strides)], rois) if self.with_shared_head: bbox_feats = self.shared_head(bbox_feats) cls_score, bbox_pred = bbox_head(bbox_feats) ms_scores.append(cls_score) if i < self.num_stages - 1: bbox_label = cls_score.argmax(dim=1) rois = bbox_head.regress_by_class(rois, bbox_label, bbox_pred, img_meta[0]) cls_score = sum(ms_scores) / float(len(ms_scores)) bboxes, scores = self.bbox_head[-1].get_det_bboxes( rois, cls_score, bbox_pred, img_shape, scale_factor, rescale=False, cfg=None) aug_bboxes.append(bboxes) aug_scores.append(scores) # after merging, bboxes will be rescaled to the original image size merged_bboxes, merged_scores = merge_aug_bboxes( aug_bboxes, aug_scores, img_metas, rcnn_test_cfg) det_bboxes, det_labels = multiclass_nms(merged_bboxes, merged_scores, rcnn_test_cfg.score_thr, rcnn_test_cfg.nms, rcnn_test_cfg.max_per_img) bbox_result = bbox2result(det_bboxes, det_labels, self.bbox_head[-1].num_classes) if self.with_mask: if det_bboxes.shape[0] == 0: segm_result = [[] for _ in range(self.mask_head[-1].num_classes - 1)] else: aug_masks = [] aug_img_metas = [] for x, img_meta in zip(self.extract_feats(imgs), img_metas): img_shape = img_meta[0]['img_shape'] scale_factor = img_meta[0]['scale_factor'] flip = img_meta[0]['flip'] _bboxes = bbox_mapping(det_bboxes[:, :4], img_shape, scale_factor, flip) mask_rois = bbox2roi([_bboxes]) for i in range(self.num_stages): mask_feats = self.mask_roi_extractor[i]( x[:len(self.mask_roi_extractor[i].featmap_strides )], mask_rois) if self.with_shared_head: mask_feats = self.shared_head(mask_feats) mask_pred = self.mask_head[i](mask_feats) aug_masks.append(mask_pred.sigmoid().cpu().numpy()) aug_img_metas.append(img_meta) merged_masks = merge_aug_masks(aug_masks, aug_img_metas, self.test_cfg.rcnn) ori_shape = img_metas[0][0]['ori_shape'] segm_result = self.mask_head[-1].get_seg_masks( merged_masks, det_bboxes, det_labels, rcnn_test_cfg, ori_shape, scale_factor=1.0, rescale=False) return bbox_result, segm_result else: return bbox_result def show_result(self, data, result, **kwargs): if self.with_mask: ms_bbox_result, ms_segm_result = result if isinstance(ms_bbox_result, dict): result = (ms_bbox_result['ensemble'], ms_segm_result['ensemble']) else: if isinstance(result, dict): result = result['ensemble'] super(CascadeRCNN, self).show_result(data, result, **kwargs)