[Dygraph]Add cascade (#1859)

* add cascade mask

* add cascade rcnn

* update code

* remove comments

configs/_base_/models/cascade_mask_rcnn_r50_fpn.yml

+architecture: CascadeRCNN
+pretrain_weights: https://paddle-imagenet-models-name.bj.bcebos.com/ResNet50_cos_pretrained.tar
+weights: output/cascade_mask_rcnn_r50_fpn_1x_coco/model_final
+load_static_weights: True
+roi_stages: 3
+
+# Model Achitecture
+CascadeRCNN:
+  # model anchor info flow
+  anchor: Anchor
+  proposal: Proposal
+  mask: Mask
+  # model feat info flow
+  backbone: ResNet
+  neck: FPN
+  rpn_head: RPNHead
+  bbox_head: BBoxHead
+  mask_head: MaskHead
+  # post process
+  bbox_post_process: BBoxPostProcess
+  mask_post_process: MaskPostProcess
+
+ResNet:
+  # index 0 stands for res2
+  depth: 50
+  norm_type: bn
+  freeze_at: 0
+  return_idx: [0,1,2,3]
+  num_stages: 4
+
+FPN:
+  in_channels: [256, 512, 1024, 2048]
+  out_channel: 256
+  min_level: 0
+  max_level: 4
+  spatial_scale: [0.25, 0.125, 0.0625, 0.03125]
+
+RPNHead:
+  rpn_feat:
+    name: RPNFeat
+    feat_in: 256
+    feat_out: 256
+  anchor_per_position: 3
+  rpn_channel: 256
+
+Anchor:
+  anchor_generator:
+    name: AnchorGeneratorRPN
+    aspect_ratios: [0.5, 1.0, 2.0]
+    anchor_start_size: 32
+    stride: [4., 4.]
+  anchor_target_generator:
+    name: AnchorTargetGeneratorRPN
+    batch_size_per_im: 256
+    fg_fraction: 0.5
+    negative_overlap: 0.3
+    positive_overlap: 0.7
+    straddle_thresh: 0.0
+
+Proposal:
+  proposal_generator:
+    name: ProposalGenerator
+    min_size: 0.0
+    nms_thresh: 0.7
+    train_pre_nms_top_n: 2000
+    train_post_nms_top_n: 2000
+    infer_pre_nms_top_n: 1000
+    infer_post_nms_top_n: 1000
+  proposal_target_generator:
+    name: ProposalTargetGenerator
+    batch_size_per_im: 512
+    bbox_reg_weights: [0.1, 0.1, 0.2, 0.2]
+    bg_thresh_hi: [0.5, 0.6, 0.7]
+    bg_thresh_lo: [0.0, 0.0, 0.0]
+    fg_thresh: [0.5, 0.6, 0.7]
+    fg_fraction: 0.25
+    is_cls_agnostic: true
+
+BBoxHead:
+  bbox_feat:
+    name: BBoxFeat
+    roi_extractor:
+      name: RoIAlign
+      resolution: 7
+      sampling_ratio: 2
+    head_feat:
+      name: TwoFCHead
+      in_dim: 256
+      mlp_dim: 1024
+  in_feat: 1024
+  cls_agnostic: true
+
+BBoxPostProcess:
+  decode:
+    name: RCNNBox
+    num_classes: 81
+    batch_size: 1
+  nms:
+    name: MultiClassNMS
+    keep_top_k: 100
+    score_threshold: 0.05
+    nms_threshold: 0.5
+
+Mask:
+  mask_target_generator:
+    name: MaskTargetGenerator
+    mask_resolution: 28
+
+MaskHead:
+  mask_feat:
+    name: MaskFeat
+    num_convs: 4
+    feat_in: 256
+    feat_out: 256
+    mask_roi_extractor:
+      name: RoIAlign
+      resolution: 14
+      sampling_ratio: 2
+    share_bbox_feat: False
+  feat_in: 256
+
+
+MaskPostProcess:
+  mask_resolution: 28

configs/_base_/models/cascade_rcnn_r50_fpn.yml

+architecture: CascadeRCNN
+pretrain_weights: https://paddle-imagenet-models-name.bj.bcebos.com/ResNet50_cos_pretrained.tar
+weights: output/cascade_rcnn_r50_fpn_1x_coco/model_final
+load_static_weights: True
+roi_stages: 3
+
+# Model Achitecture
+CascadeRCNN:
+  # model anchor info flow
+  anchor: Anchor
+  proposal: Proposal
+  # model feat info flow
+  backbone: ResNet
+  neck: FPN
+  rpn_head: RPNHead
+  bbox_head: BBoxHead
+  # post process
+  bbox_post_process: BBoxPostProcess
+
+ResNet:
+  # index 0 stands for res2
+  depth: 50
+  norm_type: bn
+  freeze_at: 0
+  return_idx: [0,1,2,3]
+  num_stages: 4
+
+FPN:
+  in_channels: [256, 512, 1024, 2048]
+  out_channel: 256
+  min_level: 0
+  max_level: 4
+  spatial_scale: [0.25, 0.125, 0.0625, 0.03125]
+
+RPNHead:
+  rpn_feat:
+    name: RPNFeat
+    feat_in: 256
+    feat_out: 256
+  anchor_per_position: 3
+  rpn_channel: 256
+
+Anchor:
+  anchor_generator:
+    name: AnchorGeneratorRPN
+    aspect_ratios: [0.5, 1.0, 2.0]
+    anchor_start_size: 32
+    stride: [4., 4.]
+  anchor_target_generator:
+    name: AnchorTargetGeneratorRPN
+    batch_size_per_im: 256
+    fg_fraction: 0.5
+    negative_overlap: 0.3
+    positive_overlap: 0.7
+    straddle_thresh: 0.0
+
+Proposal:
+  proposal_generator:
+    name: ProposalGenerator
+    min_size: 0.0
+    nms_thresh: 0.7
+    train_pre_nms_top_n: 2000
+    train_post_nms_top_n: 2000
+    infer_pre_nms_top_n: 1000
+    infer_post_nms_top_n: 1000
+  proposal_target_generator:
+    name: ProposalTargetGenerator
+    batch_size_per_im: 512
+    bbox_reg_weights: [0.1, 0.1, 0.2, 0.2]
+    bg_thresh_hi: [0.5, 0.6, 0.7]
+    bg_thresh_lo: [0.0, 0.0, 0.0]
+    fg_thresh: [0.5, 0.6, 0.7]
+    fg_fraction: 0.25
+    is_cls_agnostic: true
+
+BBoxHead:
+  bbox_feat:
+    name: BBoxFeat
+    roi_extractor:
+      name: RoIAlign
+      resolution: 7
+      sampling_ratio: 2
+    head_feat:
+      name: TwoFCHead
+      in_dim: 256
+      mlp_dim: 1024
+  in_feat: 1024
+  cls_agnostic: true
+
+BBoxPostProcess:
+  decode:
+    name: RCNNBox
+    num_classes: 81
+    batch_size: 1
+  nms:
+    name: MultiClassNMS
+    keep_top_k: 100
+    score_threshold: 0.05
+    nms_threshold: 0.5

configs/_base_/models/faster_rcnn_r50.yml

@@ -59,7 +59,7 @@ Proposal:
   proposal_target_generator:
     name: ProposalTargetGenerator
     batch_size_per_im: 512
-    bbox_reg_weights: [[0.1, 0.1, 0.2, 0.2],]
+    bbox_reg_weights: [0.1, 0.1, 0.2, 0.2]
     bg_thresh_hi: [0.5,]
     bg_thresh_lo: [0.0,]
     fg_thresh: [0.5,]

configs/_base_/models/faster_rcnn_r50_fpn.yml

@@ -66,7 +66,7 @@ Proposal:
   proposal_target_generator:
     name: ProposalTargetGenerator
     batch_size_per_im: 512
-    bbox_reg_weights: [[0.1, 0.1, 0.2, 0.2],]
+    bbox_reg_weights: [0.1, 0.1, 0.2, 0.2]
     bg_thresh_hi: [0.5,]
     bg_thresh_lo: [0.0,]
     fg_thresh: [0.5,]

configs/_base_/models/mask_rcnn_r50.yml

@@ -60,7 +60,7 @@ Proposal:
   proposal_target_generator:
     name: ProposalTargetGenerator
     batch_size_per_im: 512
-    bbox_reg_weights: [[0.1, 0.1, 0.2, 0.2],]
+    bbox_reg_weights: [0.1, 0.1, 0.2, 0.2]
     bg_thresh_hi: [0.5,]
     bg_thresh_lo: [0.0,]
     fg_thresh: [0.5,]

configs/_base_/models/mask_rcnn_r50_fpn.yml

@@ -68,7 +68,7 @@ Proposal:
   proposal_target_generator:
     name: ProposalTargetGenerator
     batch_size_per_im: 512
-    bbox_reg_weights: [[0.1, 0.1, 0.2, 0.2],]
+    bbox_reg_weights: [0.1, 0.1, 0.2, 0.2]
     bg_thresh_hi: [0.5,]
     bg_thresh_lo: [0.0,]
     fg_thresh: [0.5,]

configs/_base_/readers/faster_fpn_reader.yml

@@ -4,7 +4,6 @@ TrainReader:
     fields: ['image', 'im_info', 'im_id', 'gt_bbox', 'gt_class', 'is_crowd']
   sample_transforms:
   - DecodeImage: {to_rgb: true}
-  # check
   - RandomFlipImage: {prob: 0.5}
   - NormalizeImage: {is_channel_first: false, is_scale: true, mean: [0.485,0.456,0.406], std: [0.229, 0.224,0.225]}
   - ResizeImage: {target_size: 800, max_size: 1333, interp: 1, use_cv2: true}

configs/_base_/runtime.yml

 use_gpu: true
 log_iter: 20
 save_dir: output
-snapshot_epoch: 2
+snapshot_epoch: 1

configs/cascade_mask_rcnn_r50_fpn_1x_coco.yml

+_BASE_: [
+  './_base_/models/cascade_mask_rcnn_r50_fpn.yml',
+  './_base_/optimizers/rcnn_1x.yml',
+  './_base_/datasets/coco.yml',
+  './_base_/readers/mask_fpn_reader.yml',
+  './_base_/runtime.yml',
+]

configs/cascade_rcnn_r50_fpn_1x_coco.yml

+_BASE_: [
+  './_base_/models/cascade_rcnn_r50_fpn.yml',
+  './_base_/optimizers/rcnn_1x.yml',
+  './_base_/datasets/coco.yml',
+  './_base_/readers/faster_fpn_reader.yml',
+  './_base_/runtime.yml',
+]

ppdet/modeling/architecture/cascade_rcnn.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved. 
+#   
+# Licensed under the Apache License, Version 2.0 (the "License");   
+# you may not use this file except in compliance with the License.  
+# You may obtain a copy of the License at   
+#   
+#     http://www.apache.org/licenses/LICENSE-2.0    
+#   
+# Unless required by applicable law or agreed to in writing, software   
+# distributed under the License is distributed on an "AS IS" BASIS, 
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  
+# See the License for the specific language governing permissions and   
+# limitations under the License.
+
 from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
-from paddle import fluid
+import paddle
 from ppdet.core.workspace import register
 from .meta_arch import BaseArch
 
@@ -12,115 +26,149 @@ __all__ = ['CascadeRCNN']
 @register
 class CascadeRCNN(BaseArch):
     __category__ = 'architecture'
-    __shared__ = ['num_stages']
+    __shared__ = ['roi_stages']
     __inject__ = [
         'anchor',
         'proposal',
         'mask',
         'backbone',
+        'neck',
         'rpn_head',
         'bbox_head',
         'mask_head',
+        'bbox_post_process',
+        'mask_post_process',
     ]
 
     def __init__(self,
                  anchor,
                  proposal,
-                 mask,
                  backbone,
                  rpn_head,
                  bbox_head,
-                 mask_head,
-                 num_stages=3,
-                 *args,
-                 **kwargs):
-        super(CascadeRCNN, self).__init__(*args, **kwargs)
+                 bbox_post_process,
+                 neck=None,
+                 mask=None,
+                 mask_head=None,
+                 mask_post_process=None,
+                 roi_stages=3):
+        super(CascadeRCNN, self).__init__()
         self.anchor = anchor
         self.proposal = proposal
-        self.mask = mask
         self.backbone = backbone
         self.rpn_head = rpn_head
         self.bbox_head = bbox_head
+        self.bbox_post_process = bbox_post_process
+        self.neck = neck
+        self.mask = mask
         self.mask_head = mask_head
-        self.num_stages = num_stages
+        self.mask_post_process = mask_post_process
+        self.roi_stages = roi_stages
+        self.with_mask = mask is not None
 
     def model_arch(self, ):
         # Backbone
-        bb_out = self.backbone(self.gbd)
-        self.gbd.update(bb_out)
+        body_feats = self.backbone(self.inputs)
+
+        # Neck
+        if self.neck is not None:
+            body_feats, spatial_scale = self.neck(body_feats)
 
         # RPN
-        rpn_head_out = self.rpn_head(self.gbd)
-        self.gbd.update(rpn_head_out)
+        # rpn_head returns two list: rpn_feat, rpn_head_out 
+        # each element in rpn_feats contains rpn feature on each level,
+        # and the length is 1 when the neck is not applied.
+        # each element in rpn_head_out contains (rpn_rois_score, rpn_rois_delta)
+        rpn_feat, self.rpn_head_out = self.rpn_head(self.inputs, body_feats)
 
         # Anchor
-        anchor_out = self.anchor(self.gbd)
-        self.gbd.update(anchor_out)
-
-        self.gbd['stage'] = 0
-        for i in range(self.num_stages):
-            self.gbd.update_v('stage', i)
+        # anchor_out returns a list,
+        # each element contains (anchor, anchor_var)
+        self.anchor_out = self.anchor(rpn_feat)
+
+        # Proposal RoI
+        # compute targets here when training
+        rois = None
+        bbox_head_out = None
+        max_overlap = None
+        self.bbox_head_list = []
+        rois_list = []
+        for i in range(self.roi_stages):
             # Proposal BBox
-            proposal_out = self.proposal(self.gbd)
-            self.gbd.update({"proposal_" + str(i): proposal_out})
-
+            rois = self.proposal(
+                self.inputs,
+                self.rpn_head_out,
+                self.anchor_out,
+                i,
+                rois,
+                bbox_head_out,
+                max_overlap=max_overlap)
+            rois_list.append(rois)
+            max_overlap = self.proposal.get_max_overlap()
             # BBox Head
-            bbox_head_out = self.bbox_head(self.gbd)
-            self.gbd.update({'bbox_head_' + str(i): bbox_head_out})
-
-            refine_bbox_out = self.proposal.refine_bbox(self.gbd)
-            self.gbd['proposal_' + str(i)].update(refine_bbox_out)
-
-        if self.gbd['mode'] == 'infer':
-            bbox_out = self.proposal.post_process(self.gbd)
-            self.gbd.update(bbox_out)
-
-        # Mask 
-        mask_out = self.mask(self.gbd)
-        self.gbd.update(mask_out)
-
+            bbox_feat, bbox_head_out, _ = self.bbox_head(body_feats, rois,
+                                                         spatial_scale, i)
+            self.bbox_head_list.append(bbox_head_out)
+
+        if self.inputs['mode'] == 'infer':
+            bbox_pred, bboxes = self.bbox_head.get_cascade_prediction(
+                self.bbox_head_list, rois_list)
+            self.bboxes = self.bbox_post_process(
+                bbox_pred,
+                bboxes,
+                self.inputs['im_shape'],
+                self.inputs['scale_factor'],
+                var_weight=3.)
+
+        if self.with_mask:
+            rois = rois_list[-1]
+            rois_has_mask_int32 = None
+            if self.inputs['mode'] == 'train':
+                bbox_targets = self.proposal.get_targets()[-1]
+                self.bboxes, rois_has_mask_int32 = self.mask(self.inputs, rois,
+                                                             bbox_targets)
             # Mask Head 
-        mask_head_out = self.mask_head(self.gbd)
-        self.gbd.update(mask_head_out)
-
-        if self.gbd['mode'] == 'infer':
-            mask_out = self.mask.post_process(self.gbd)
-            self.gbd.update(mask_out)
+            self.mask_head_out = self.mask_head(
+                self.inputs, body_feats, self.bboxes, bbox_feat,
+                rois_has_mask_int32, spatial_scale)
 
     def get_loss(self, ):
-        outs = {}
-        losses = []
-
-        rpn_cls_loss, rpn_reg_loss = self.rpn_head.get_loss(self.gbd)
-        outs['loss_rpn_cls'] = rpn_cls_loss
-        outs['loss_rpn_reg'] = rpn_reg_loss
-        losses.extend([rpn_cls_loss, rpn_reg_loss])
-
-        bbox_cls_loss_list = []
-        bbox_reg_loss_list = []
-        for i in range(self.num_stages):
-            self.gbd.update_v('stage', i)
-            bbox_cls_loss, bbox_reg_loss = self.bbox_head.get_loss(self.gbd)
-            bbox_cls_loss_list.append(bbox_cls_loss)
-            bbox_reg_loss_list.append(bbox_reg_loss)
-            outs['loss_bbox_cls_' + str(i)] = bbox_cls_loss
-            outs['loss_bbox_reg_' + str(i)] = bbox_reg_loss
-        losses.extend(bbox_cls_loss_list)
-        losses.extend(bbox_reg_loss_list)
-
-        mask_loss = self.mask_head.get_loss(self.gbd)
-        outs['mask_loss'] = mask_loss
-        losses.append(mask_loss)
-
-        loss = fluid.layers.sum(losses)
-        outs['loss'] = loss
-        return outs
-
-    def get_pred(self, ):
-        outs = {
-            'bbox': self.gbd['predicted_bbox'].numpy(),
-            'bbox_nums': self.gbd['predicted_bbox_nums'].numpy(),
-            'mask': self.gbd['predicted_mask'].numpy(),
-            'im_id': self.gbd['im_id'].numpy(),
+        loss = {}
+
+        # RPN loss
+        rpn_loss_inputs = self.anchor.generate_loss_inputs(
+            self.inputs, self.rpn_head_out, self.anchor_out)
+        loss_rpn = self.rpn_head.get_loss(rpn_loss_inputs)
+        loss.update(loss_rpn)
+
+        # BBox loss
+        bbox_targets_list = self.proposal.get_targets()
+        loss_bbox = self.bbox_head.get_loss(self.bbox_head_list,
+                                            bbox_targets_list)
+        loss.update(loss_bbox)
+
+        if self.with_mask:
+            # Mask loss
+            mask_targets = self.mask.get_targets()
+            loss_mask = self.mask_head.get_loss(self.mask_head_out,
+                                                mask_targets)
+            loss.update(loss_mask)
+
+        total_loss = paddle.add_n(list(loss.values()))
+        loss.update({'loss': total_loss})
+        return loss
+
+    def get_pred(self, return_numpy=True):
+        bbox, bbox_num = self.bboxes
+        output = {
+            'bbox': bbox.numpy(),
+            'bbox_num': bbox_num.numpy(),
+            'im_id': self.inputs['im_id'].numpy(),
         }
-        return inputs
+
+        if self.with_mask:
+            mask = self.mask_post_process(self.bboxes, self.mask_head_out,
+                                          self.inputs['im_shape'],
+                                          self.inputs['scale_factor'])
+            output.update(mask)
+        return output

ppdet/modeling/architecture/faster_rcnn.py

@@ -86,7 +86,7 @@ class FasterRCNN(BaseArch):
 
         # BBox loss
         bbox_targets = self.proposal.get_targets()
-        loss_bbox = self.bbox_head.get_loss(self.bbox_head_out, bbox_targets)
+        loss_bbox = self.bbox_head.get_loss([self.bbox_head_out], bbox_targets)
         loss.update(loss_bbox)
         total_loss = paddle.add_n(list(loss.values()))
         loss.update({'loss': total_loss})

ppdet/modeling/architecture/mask_rcnn.py

@@ -121,7 +121,7 @@ class MaskRCNN(BaseArch):
 
         # BBox loss
         bbox_targets = self.proposal.get_targets()
-        loss_bbox = self.bbox_head.get_loss(self.bbox_head_out, bbox_targets)
+        loss_bbox = self.bbox_head.get_loss([self.bbox_head_out], bbox_targets)
         loss.update(loss_bbox)
 
         # Mask loss

ppdet/modeling/backbone/resnet.py

@@ -166,16 +166,16 @@ class BottleNeck(nn.Layer):
             name=conv_name3)
 
     def forward(self, inputs):
-        if self.shortcut:
-            short = inputs
-        else:
-            short = self.short(inputs)
 
         out = self.branch2a(inputs)
         out = self.branch2b(out)
         out = self.branch2c(out)
+        if self.shortcut:
+            short = inputs
+        else:
+            short = self.short(inputs)
 
-        out = paddle.add(x=short, y=out)
+        out = paddle.add(x=out, y=short)
         out = F.relu(out)
 
         return out

ppdet/modeling/bbox.py

@@ -127,7 +127,12 @@ class Proposal(object):
             rois_num_per_level=rpn_rois_num_list)
         return rois_collect, rois_num_collect
 
-    def generate_proposal_target(self, inputs, rois, rois_num, stage=0):
+    def generate_proposal_target(self,
+                                 inputs,
+                                 rois,
+                                 rois_num,
+                                 stage=0,
+                                 max_overlap=None):
         outs = self.proposal_target_generator(
             rpn_rois=rois,
             rpn_rois_num=rois_num,
@@ -135,32 +140,36 @@ class Proposal(object):
             is_crowd=inputs['is_crowd'],
             gt_boxes=inputs['gt_bbox'],
             im_info=inputs['im_info'],
-            stage=stage)
+            stage=stage,
+            max_overlap=max_overlap)
         rois = outs[0]
-        rois_num = outs[-1]
+        max_overlap = outs[-1]
+        rois_num = outs[-2]
         targets = {
             'labels_int32': outs[1],
             'bbox_targets': outs[2],
             'bbox_inside_weights': outs[3],
             'bbox_outside_weights': outs[4]
         }
-        return rois, rois_num, targets
+        return rois, rois_num, targets, max_overlap
 
-    def refine_bbox(self, rois, bbox_delta, stage=0):
-        out_dim = bbox_delta.shape[1] / 4
-        bbox_delta_r = fluid.layers.reshape(bbox_delta, (-1, out_dim, 4))
-        bbox_delta_s = fluid.layers.slice(
+    def refine_bbox(self, roi, bbox_delta, stage=1):
+        out_dim = bbox_delta.shape[1] // 4
+        bbox_delta_r = paddle.reshape(bbox_delta, (-1, out_dim, 4))
+        bbox_delta_s = paddle.slice(
             bbox_delta_r, axes=[1], starts=[1], ends=[2])
 
+        reg_weights = [
+            i / stage for i in self.proposal_target_generator.bbox_reg_weights
+        ]
         refined_bbox = ops.box_coder(
-            prior_box=rois,
-            prior_box_var=self.proposal_target_generator.bbox_reg_weights[
-                stage],
+            prior_box=roi,
+            prior_box_var=reg_weights,
             target_box=bbox_delta_s,
             code_type='decode_center_size',
             box_normalized=False,
             axis=1)
-        refined_bbox = fluid.layers.reshape(refined_bbox, shape=[-1, 4])
+        refined_bbox = paddle.reshape(refined_bbox, shape=[-1, 4])
         return refined_bbox
 
     def __call__(self,
@@ -169,30 +178,26 @@ class Proposal(object):
                  anchor_out,
                  stage=0,
                  proposal_out=None,
-                 bbox_head_outs=None,
-                 refined=False):
-        if refined:
-            assert proposal_out is not None, "If proposal has been refined, proposal_out should not be None."
-            return proposal_out
+                 bbox_head_out=None,
+                 max_overlap=None):
         if stage == 0:
             roi, rois_num = self.generate_proposal(inputs, rpn_head_out,
                                                    anchor_out)
-            self.proposals_list = []
             self.targets_list = []
+            self.max_overlap = None
 
         else:
-            bbox_delta = bbox_head_outs[stage][0]
-            roi = self.refine_bbox(proposal_out[0], bbox_delta, stage - 1)
+            bbox_delta = bbox_head_out[1]
+            roi = self.refine_bbox(proposal_out[0], bbox_delta, stage)
             rois_num = proposal_out[1]
         if inputs['mode'] == 'train':
-            roi, rois_num, targets = self.generate_proposal_target(
-                inputs, roi, rois_num, stage)
+            roi, rois_num, targets, self.max_overlap = self.generate_proposal_target(
+                inputs, roi, rois_num, stage, self.max_overlap)
             self.targets_list.append(targets)
-        self.proposals_list.append((roi, rois_num))
         return roi, rois_num
 
     def get_targets(self):
         return self.targets_list
 
-    def get_proposals(self):
-        return self.proposals_list
+    def get_max_overlap(self):
+        return self.max_overlap

ppdet/modeling/head/bbox_head.py

@@ -29,39 +29,42 @@ from ..backbone.resnet import Blocks
 @register
 class TwoFCHead(nn.Layer):
 
-    __shared__ = ['num_stages']
+    __shared__ = ['roi_stages']
 
-    def __init__(self, in_dim=256, mlp_dim=1024, resolution=7, num_stages=1):
+    def __init__(self, in_dim=256, mlp_dim=1024, resolution=7, roi_stages=1):
         super(TwoFCHead, self).__init__()
         self.in_dim = in_dim
         self.mlp_dim = mlp_dim
-        self.num_stages = num_stages
+        self.roi_stages = roi_stages
         fan = in_dim * resolution * resolution
         self.fc6_list = []
         self.fc6_relu_list = []
         self.fc7_list = []
         self.fc7_relu_list = []
-        for stage in range(num_stages):
+        for stage in range(roi_stages):
             fc6_name = 'fc6_{}'.format(stage)
             fc7_name = 'fc7_{}'.format(stage)
+            lr_factor = 2**stage
             fc6 = self.add_sublayer(
                 fc6_name,
                 nn.Linear(
                     in_dim * resolution * resolution,
                     mlp_dim,
                     weight_attr=ParamAttr(
+                        learning_rate=lr_factor,
                         initializer=XavierUniform(fan_out=fan)),
                     bias_attr=ParamAttr(
-                        learning_rate=2., regularizer=L2Decay(0.))))
+                        learning_rate=2. * lr_factor, regularizer=L2Decay(0.))))
             fc6_relu = self.add_sublayer(fc6_name + 'act', ReLU())
             fc7 = self.add_sublayer(
                 fc7_name,
                 nn.Linear(
                     mlp_dim,
                     mlp_dim,
-                    weight_attr=ParamAttr(initializer=XavierUniform()),
+                    weight_attr=ParamAttr(
+                        learning_rate=lr_factor, initializer=XavierUniform()),
                     bias_attr=ParamAttr(
-                        learning_rate=2., regularizer=L2Decay(0.))))
+                        learning_rate=2. * lr_factor, regularizer=L2Decay(0.))))
             fc7_relu = self.add_sublayer(fc7_name + 'act', ReLU())
             self.fc6_list.append(fc6)
             self.fc6_relu_list.append(fc6_relu)
@@ -102,16 +105,17 @@ class BBoxFeat(nn.Layer):
         super(BBoxFeat, self).__init__()
         self.roi_extractor = roi_extractor
         self.head_feat = head_feat
+        self.rois_feat_list = []
 
     def forward(self, body_feats, rois, spatial_scale, stage=0):
         rois_feat = self.roi_extractor(body_feats, rois, spatial_scale)
         bbox_feat = self.head_feat(rois_feat, stage)
-        return bbox_feat, self.head_feat
+        return rois_feat, bbox_feat
 
 
 @register
 class BBoxHead(nn.Layer):
-    __shared__ = ['num_classes', 'num_stages']
+    __shared__ = ['num_classes', 'roi_stages']
     __inject__ = ['bbox_feat']
 
     def __init__(self,
@@ -119,49 +123,65 @@ class BBoxHead(nn.Layer):
                  in_feat=1024,
                  num_classes=81,
                  cls_agnostic=False,
-                 num_stages=1,
+                 roi_stages=1,
                  with_pool=False,
                  score_stage=[0, 1, 2],
                  delta_stage=[2]):
         super(BBoxHead, self).__init__()
         self.num_classes = num_classes
+        self.cls_agnostic = cls_agnostic
         self.delta_dim = 2 if cls_agnostic else num_classes
         self.bbox_feat = bbox_feat
-        self.num_stages = num_stages
+        self.roi_stages = roi_stages
         self.bbox_score_list = []
         self.bbox_delta_list = []
+        self.roi_feat_list = [[] for i in range(roi_stages)]
         self.with_pool = with_pool
         self.score_stage = score_stage
         self.delta_stage = delta_stage
-        for stage in range(num_stages):
+        for stage in range(roi_stages):
             score_name = 'bbox_score_{}'.format(stage)
             delta_name = 'bbox_delta_{}'.format(stage)
+            lr_factor = 2**stage
             bbox_score = self.add_sublayer(
                 score_name,
                 nn.Linear(
                     in_feat,
                     1 * self.num_classes,
-                    weight_attr=ParamAttr(initializer=Normal(
+                    weight_attr=ParamAttr(
+                        learning_rate=lr_factor,
+                        initializer=Normal(
                             mean=0.0, std=0.01)),
                     bias_attr=ParamAttr(
-                        learning_rate=2., regularizer=L2Decay(0.))))
+                        learning_rate=2. * lr_factor, regularizer=L2Decay(0.))))
 
             bbox_delta = self.add_sublayer(
                 delta_name,
                 nn.Linear(
                     in_feat,
                     4 * self.delta_dim,
-                    weight_attr=ParamAttr(initializer=Normal(
+                    weight_attr=ParamAttr(
+                        learning_rate=lr_factor,
+                        initializer=Normal(
                             mean=0.0, std=0.001)),
                     bias_attr=ParamAttr(
-                        learning_rate=2., regularizer=L2Decay(0.))))
+                        learning_rate=2. * lr_factor, regularizer=L2Decay(0.))))
             self.bbox_score_list.append(bbox_score)
             self.bbox_delta_list.append(bbox_delta)
 
-    def forward(self, body_feats, rois, spatial_scale, stage=0):
-        bbox_feat, head_feat_func = self.bbox_feat(body_feats, rois,
+    def forward(self,
+                body_feats=None,
+                rois=None,
+                spatial_scale=None,
+                stage=0,
+                roi_stage=-1):
+        if rois is not None:
+            rois_feat, bbox_feat = self.bbox_feat(body_feats, rois,
                                                   spatial_scale, stage)
-        bbox_head_out = []
+            self.roi_feat_list[stage] = rois_feat
+        else:
+            rois_feat = self.roi_feat_list[roi_stage]
+            bbox_feat = self.bbox_feat.head_feat(rois_feat, stage)
         if self.with_pool:
             bbox_feat_ = F.adaptive_avg_pool2d(bbox_feat, output_size=1)
             bbox_feat_ = paddle.squeeze(bbox_feat_, axis=[2, 3])
@@ -170,8 +190,8 @@ class BBoxHead(nn.Layer):
         else:
             scores = self.bbox_score_list[stage](bbox_feat)
             deltas = self.bbox_delta_list[stage](bbox_feat)
-        bbox_head_out.append((scores, deltas))
-        return bbox_feat, bbox_head_out, head_feat_func
+        bbox_head_out = (scores, deltas)
+        return bbox_feat, bbox_head_out, self.bbox_feat.head_feat
 
     def _get_head_loss(self, score, delta, target):
         # bbox cls  
@@ -198,25 +218,33 @@ class BBoxHead(nn.Layer):
             reg_name = 'loss_bbox_reg_{}'.format(lvl)
             loss_bbox_cls, loss_bbox_reg = self._get_head_loss(score, delta,
                                                                target)
-            loss_bbox[cls_name] = loss_bbox_cls
-            loss_bbox[reg_name] = loss_bbox_reg
+            loss_weight = 1. / 2**lvl
+            loss_bbox[cls_name] = loss_bbox_cls * loss_weight
+            loss_bbox[reg_name] = loss_bbox_reg * loss_weight
         return loss_bbox
 
     def get_prediction(self, bbox_head_out, rois):
-        if len(bbox_head_out) == 1:
         proposal, proposal_num = rois
-            score, delta = bbox_head_out[0]
+        score, delta = bbox_head_out
         bbox_prob = F.softmax(score)
         delta = paddle.reshape(delta, (-1, self.delta_dim, 4))
-        else:
-            num_stage = len(rois)
+        bbox_pred = (delta, bbox_prob)
+        return bbox_pred, rois
+
+    def get_cascade_prediction(self, bbox_head_out, rois):
         proposal_list = []
         prob_list = []
         delta_list = []
-            for stage, (proposals, bboxhead) in zip(rois, bboxheads):
+        for stage in range(len(rois)):
+            proposals = rois[stage]
+            bboxhead = bbox_head_out[stage]
             score, delta = bboxhead
             proposal, proposal_num = proposals
             if stage in self.score_stage:
+                if stage < 2:
+                    _, head_out, _ = self(stage=stage, roi_stage=-1)
+                    score = head_out[0]
+
                 bbox_prob = F.softmax(score)
                 prob_list.append(bbox_prob)
             if stage in self.delta_stage:
@@ -225,7 +253,7 @@ class BBoxHead(nn.Layer):
         bbox_prob = paddle.mean(paddle.stack(prob_list), axis=0)
         delta = paddle.mean(paddle.stack(delta_list), axis=0)
         proposal = paddle.mean(paddle.stack(proposal_list), axis=0)
-            delta = paddle.reshape(delta, (-1, self.out_dim, 4))
+        delta = paddle.reshape(delta, (-1, self.delta_dim, 4))
         if self.cls_agnostic:
             N, C, M = delta.shape
             delta = delta[:, 1:2, :]

ppdet/modeling/head/mask_head.py

@@ -158,6 +158,7 @@ class MaskHead(Layer):
                      stage=0,
                      bbox_head_feat_func=None):
         bbox, bbox_num = bboxes
+
         if bbox.shape[0] == 0:
             mask_head_out = bbox
         else:

ppdet/modeling/layers.py

@@ -176,11 +176,10 @@ class ProposalTargetGenerator(object):
                  fg_thresh=[.5, ],
                  bg_thresh_hi=[.5, ],
                  bg_thresh_lo=[0., ],
-                 bbox_reg_weights=[[0.1, 0.1, 0.2, 0.2]],
+                 bbox_reg_weights=[0.1, 0.1, 0.2, 0.2],
                  num_classes=81,
                  use_random=True,
-                 is_cls_agnostic=False,
-                 is_cascade_rcnn=False):
+                 is_cls_agnostic=False):
         super(ProposalTargetGenerator, self).__init__()
         self.batch_size_per_im = batch_size_per_im
         self.fg_fraction = fg_fraction
@@ -191,7 +190,6 @@ class ProposalTargetGenerator(object):
         self.num_classes = num_classes
         self.use_random = use_random
         self.is_cls_agnostic = is_cls_agnostic
-        self.is_cascade_rcnn = is_cascade_rcnn
 
     def __call__(self,
                  rpn_rois,
@@ -200,19 +198,25 @@ class ProposalTargetGenerator(object):
                  is_crowd,
                  gt_boxes,
                  im_info,
-                 stage=0):
+                 stage=0,
+                 max_overlap=None):
         rpn_rois = rpn_rois.numpy()
         rpn_rois_num = rpn_rois_num.numpy()
         gt_classes = gt_classes.numpy()
         gt_boxes = gt_boxes.numpy()
         is_crowd = is_crowd.numpy()
         im_info = im_info.numpy()
+        max_overlap = max_overlap if max_overlap is None else max_overlap.numpy(
+        )
+        reg_weights = [i / (stage + 1) for i in self.bbox_reg_weights]
+        is_cascade = True if stage > 0 else False
+        num_classes = 2 if is_cascade else self.num_classes
         outs = generate_proposal_target(
             rpn_rois, rpn_rois_num, gt_classes, is_crowd, gt_boxes, im_info,
             self.batch_size_per_im, self.fg_fraction, self.fg_thresh[stage],
-            self.bg_thresh_hi[stage], self.bg_thresh_lo[stage],
-            self.bbox_reg_weights[stage], self.num_classes, self.use_random,
-            self.is_cls_agnostic, self.is_cascade_rcnn)
+            self.bg_thresh_hi[stage], self.bg_thresh_lo[stage], reg_weights,
+            num_classes, self.use_random, self.is_cls_agnostic, is_cascade,
+            max_overlap)
         outs = [to_tensor(v) for v in outs]
         for v in outs:
             v.stop_gradient = True
@@ -268,7 +272,12 @@ class RCNNBox(object):
         self.box_normalized = box_normalized
         self.axis = axis
 
-    def __call__(self, bbox_head_out, rois, im_shape, scale_factor):
+    def __call__(self,
+                 bbox_head_out,
+                 rois,
+                 im_shape,
+                 scale_factor,
+                 var_weight=1.):
         bbox_pred, cls_prob = bbox_head_out
         roi, rois_num = rois
         origin_shape = im_shape / scale_factor
@@ -287,9 +296,10 @@ class RCNNBox(object):
         origin_shape = paddle.concat(origin_shape_list)
 
         bbox = roi / scale
+        prior_box_var = [i / var_weight for i in self.prior_box_var]
         bbox = ops.box_coder(
             prior_box=bbox,
-            prior_box_var=self.prior_box_var,
+            prior_box_var=prior_box_var,
             target_box=bbox_pred,
             code_type=self.code_type,
             box_normalized=self.box_normalized,

ppdet/modeling/post_process.py

@@ -16,8 +16,14 @@ class BBoxPostProcess(object):
         self.decode = decode
         self.nms = nms
 
-    def __call__(self, head_out, rois, im_shape, scale_factor=None):
-        bboxes, score = self.decode(head_out, rois, im_shape, scale_factor)
+    def __call__(self,
+                 head_out,
+                 rois,
+                 im_shape,
+                 scale_factor=None,
+                 var_weight=1.):
+        bboxes, score = self.decode(head_out, rois, im_shape, scale_factor,
+                                    var_weight)
         bbox_pred, bbox_num, _ = self.nms(bboxes, score)
         return bbox_pred, bbox_num
 

ppdet/py_op/bbox.py

@@ -72,7 +72,7 @@ def expand_bbox(bboxes, scale):
     w_half *= scale
     h_half *= scale
 
-    bboxes_exp = np.zeros(bboxes.shape)
+    bboxes_exp = np.zeros(bboxes.shape, dtype=np.float32)
     bboxes_exp[:, 0] = x_c - w_half
     bboxes_exp[:, 2] = x_c + w_half
     bboxes_exp[:, 1] = y_c - h_half
@@ -107,18 +107,20 @@ def bbox_overlaps(bboxes1, bboxes2):
     area1 = w1 * h1
     area2 = w2 * h2
 
-    overlaps = np.zeros((bboxes1.shape[0], bboxes2.shape[0]))
-    for ind1 in range(bboxes1.shape[0]):
-        for ind2 in range(bboxes2.shape[0]):
-            inter_x1 = np.maximum(bboxes1[ind1, 0], bboxes2[ind2, 0])
-            inter_y1 = np.maximum(bboxes1[ind1, 1], bboxes2[ind2, 1])
-            inter_x2 = np.minimum(bboxes1[ind1, 2], bboxes2[ind2, 2])
-            inter_y2 = np.minimum(bboxes1[ind1, 3], bboxes2[ind2, 3])
-            inter_w = np.maximum(inter_x2 - inter_x1 + 1, 0)
-            inter_h = np.maximum(inter_y2 - inter_y1 + 1, 0)
+    boxes1_x1, boxes1_y1, boxes1_x2, boxes1_y2 = np.split(bboxes1, 4, axis=1)
+    boxes2_x1, boxes2_y1, boxes2_x2, boxes2_y2 = np.split(bboxes2, 4, axis=1)
+
+    all_pairs_min_ymax = np.minimum(boxes1_y2, np.transpose(boxes2_y2))
+    all_pairs_max_ymin = np.maximum(boxes1_y1, np.transpose(boxes2_y1))
+    inter_h = np.maximum(all_pairs_min_ymax - all_pairs_max_ymin + 1, 0.)
+    all_pairs_min_xmax = np.minimum(boxes1_x2, np.transpose(boxes2_x2))
+    all_pairs_max_xmin = np.maximum(boxes1_x1, np.transpose(boxes2_x1))
+    inter_w = np.maximum(all_pairs_min_xmax - all_pairs_max_xmin + 1, 0.)
+
     inter_area = inter_w * inter_h
-            iou = inter_area * 1.0 / (area1[ind1] + area2[ind2] - inter_area)
-            overlaps[ind1, ind2] = iou
+
+    union_area = np.expand_dims(area1, 1) + np.expand_dims(area2, 0)
+    overlaps = inter_area / (union_area - inter_area)
     return overlaps
 
 

ppdet/py_op/target.py

@@ -90,7 +90,6 @@ def generate_rpn_anchor_target(anchors,
 @jit
 def label_anchor(anchors, gt_boxes):
     iou = bbox_overlaps(anchors, gt_boxes)
-
     # every gt's anchor's index
     gt_bbox_anchor_inds = iou.argmax(axis=0)
     gt_bbox_anchor_iou = iou[gt_bbox_anchor_inds, np.arange(iou.shape[1])]
@@ -148,6 +147,16 @@ def sample_anchor(anchor_gt_bbox_iou,
     return fg_inds, bg_inds, fg_fake_inds, fake_num
 
 
+@jit
+def filter_roi(rois, max_overlap):
+    ws = rois[:, 2] - rois[:, 0] + 1
+    hs = rois[:, 3] - rois[:, 1] + 1
+    keep = np.where((ws > 0) & (hs > 0) & (max_overlap < 1))[0]
+    if len(keep) > 0:
+        return rois[keep, :]
+    return np.zeros((1, 4)).astype('float32')
+
+
 @jit
 def generate_proposal_target(rpn_rois,
                              rpn_rois_num,
@@ -164,42 +173,38 @@ def generate_proposal_target(rpn_rois,
                              class_nums=81,
                              use_random=True,
                              is_cls_agnostic=False,
-                             is_cascade_rcnn=False):
+                             is_cascade_rcnn=False,
+                             max_overlaps=None):
 
     rois = []
     tgt_labels = []
     tgt_deltas = []
     rois_inside_weights = []
     rois_outside_weights = []
+    sampled_max_overlaps = []
     new_rois_num = []
     st_num = 0
     end_num = 0
     for im_i in range(len(rpn_rois_num)):
         length = rpn_rois_num[im_i]
         end_num += length
-
         rpn_roi = rpn_rois[st_num:end_num]
+        max_overlap = max_overlaps[st_num:end_num] if is_cascade_rcnn else None
         im_scale = im_info[im_i][2]
         rpn_roi = rpn_roi / im_scale
         gt_bbox = gt_boxes[im_i]
 
         if is_cascade_rcnn:
-            rpn_roi = rpn_roi[gt_bbox.shape[0]:, :]
-        bbox = np.vstack([gt_bbox, rpn_roi])
+            rpn_roi = filter_roi(rpn_roi, max_overlap)
+        bbox = np.vstack([gt_bbox, rpn_roi]).astype('float32')
 
         # Step1: label bbox 
-        roi_gt_bbox_inds, roi_gt_bbox_iou, labels, = label_bbox(
+        roi_gt_bbox_inds, labels, max_overlap = label_bbox(
             bbox, gt_bbox, gt_classes[im_i], is_crowd[im_i])
 
         # Step2: sample bbox 
-        if is_cascade_rcnn:
-            ws = bbox[:, 2] - bbox[:, 0] + 1
-            hs = bbox[:, 3] - bbox[:, 1] + 1
-            keep = np.where((ws > 0) & (hs > 0))[0]
-            bbox = bbox[keep]
-
         fg_inds, bg_inds, fg_nums = sample_bbox(
-            roi_gt_bbox_iou, batch_size_per_im, fg_fraction, fg_thresh,
+            max_overlap, batch_size_per_im, fg_fraction, fg_thresh,
             bg_thresh_hi, bg_thresh_lo, bbox_reg_weights, class_nums,
             use_random, is_cls_agnostic, is_cascade_rcnn)
 
@@ -210,10 +215,12 @@ def generate_proposal_target(rpn_rois,
         sampled_labels[fg_nums:] = 0
 
         sampled_boxes = bbox[sampled_inds]
+        sampled_max_overlap = max_overlap[sampled_inds]
         sampled_gt_boxes = gt_bbox[roi_gt_bbox_inds[sampled_inds]]
-        sampled_gt_boxes[fg_nums:, :] = gt_bbox[0]
+        sampled_gt_boxes[fg_nums:, :] = 0
         sampled_deltas = compute_bbox_targets(sampled_boxes, sampled_gt_boxes,
                                               sampled_labels, bbox_reg_weights)
+        sampled_deltas[fg_nums:, :] = 0
         sampled_deltas, bbox_inside_weights = expand_bbox_targets(
             sampled_deltas, class_nums, is_cls_agnostic)
         bbox_outside_weights = np.array(
@@ -228,6 +235,7 @@ def generate_proposal_target(rpn_rois,
         tgt_deltas.append(sampled_deltas)
         rois_inside_weights.append(bbox_inside_weights)
         rois_outside_weights.append(bbox_outside_weights)
+        sampled_max_overlaps.append(sampled_max_overlap)
 
     rois = np.concatenate(rois, axis=0).astype(np.float32)
     tgt_labels = np.concatenate(
@@ -237,23 +245,20 @@ def generate_proposal_target(rpn_rois,
         rois_inside_weights, axis=0).astype(np.float32)
     rois_outside_weights = np.concatenate(
         rois_outside_weights, axis=0).astype(np.float32)
+    sampled_max_overlaps = np.concatenate(
+        sampled_max_overlaps, axis=0).astype(np.float32)
     new_rois_num = np.asarray(new_rois_num, np.int32)
-    return rois, tgt_labels, tgt_deltas, rois_inside_weights, rois_outside_weights, new_rois_num
+    return rois, tgt_labels, tgt_deltas, rois_inside_weights, rois_outside_weights, new_rois_num, sampled_max_overlaps
 
 
 @jit
-def label_bbox(boxes,
-               gt_boxes,
-               gt_classes,
-               is_crowd,
-               class_nums=81,
-               is_cascade_rcnn=False):
+def label_bbox(boxes, gt_boxes, gt_classes, is_crowd, class_nums=81):
 
     iou = bbox_overlaps(boxes, gt_boxes)
 
     # every roi's gt box's index  
     roi_gt_bbox_inds = np.zeros((boxes.shape[0]), dtype=np.int32)
-    roi_gt_bbox_iou = np.zeros((boxes.shape[0], class_nums))
+    roi_gt_bbox_iou = np.zeros((boxes.shape[0], class_nums), dtype=np.float32)
 
     iou_argmax = iou.argmax(axis=1)
     iou_max = iou.max(axis=1)
@@ -267,13 +272,14 @@ def label_bbox(boxes,
     crowd_ind = np.where(is_crowd)[0]
     roi_gt_bbox_iou[crowd_ind] = -1
 
+    max_overlap = roi_gt_bbox_iou.max(axis=1)
     labels = roi_gt_bbox_iou.argmax(axis=1)
 
-    return roi_gt_bbox_inds, roi_gt_bbox_iou, labels
+    return roi_gt_bbox_inds, labels, max_overlap
 
 
 @jit
-def sample_bbox(roi_gt_bbox_iou,
+def sample_bbox(max_overlap,
                 batch_size_per_im,
                 fg_fraction,
                 fg_thresh,
@@ -285,27 +291,26 @@ def sample_bbox(roi_gt_bbox_iou,
                 is_cls_agnostic=False,
                 is_cascade_rcnn=False):
 
-    roi_gt_bbox_iou_max = roi_gt_bbox_iou.max(axis=1)
     rois_per_image = int(batch_size_per_im)
     fg_rois_per_im = int(np.round(fg_fraction * rois_per_image))
 
     if is_cascade_rcnn:
-        fg_inds = np.where(roi_gt_bbox_iou_max >= fg_thresh)[0]
-        bg_inds = np.where((roi_gt_bbox_iou_max < bg_thresh_hi) & (
-            roi_gt_bbox_iou_max >= bg_thresh_lo))[0]
+        fg_inds = np.where(max_overlap >= fg_thresh)[0]
+        bg_inds = np.where((max_overlap < bg_thresh_hi) & (max_overlap >=
+                                                           bg_thresh_lo))[0]
         fg_nums = fg_inds.shape[0]
         bg_nums = bg_inds.shape[0]
     else:
         # sampe fg 
-        fg_inds = np.where(roi_gt_bbox_iou_max >= fg_thresh)[0]
+        fg_inds = np.where(max_overlap >= fg_thresh)[0]
         fg_nums = np.minimum(fg_rois_per_im, fg_inds.shape[0])
         if (fg_inds.shape[0] > fg_nums) and use_random:
             fg_inds = np.random.choice(fg_inds, size=fg_nums, replace=False)
         fg_inds = fg_inds[:fg_nums]
 
         # sample bg 
-        bg_inds = np.where((roi_gt_bbox_iou_max < bg_thresh_hi) & (
-            roi_gt_bbox_iou_max >= bg_thresh_lo))[0]
+        bg_inds = np.where((max_overlap < bg_thresh_hi) & (max_overlap >=
+                                                           bg_thresh_lo))[0]
         bg_nums = rois_per_image - fg_nums
         bg_nums = np.minimum(bg_nums, bg_inds.shape[0])
         if (bg_inds.shape[0] > bg_nums) and use_random:

tools/train.py

@@ -171,11 +171,6 @@ def run(FLAGS, cfg, place):
 
             # Model Backward
             loss = outputs['loss']
-            if ParallelEnv().nranks > 1:
-                loss = model.scale_loss(loss)
-                loss.backward()
-                model.apply_collective_grads()
-            else:
             loss.backward()
             optimizer.step()
             curr_lr = optimizer.get_lr()