Refine and fix some code for faster-rcnn. (#13135)

* Fix bug in generate_proposals_op.
* Fix data type for RoIs.
* Refine and fix rpn_target_assign_op.
* Add the missing file bbox_util.h
* Rename BoxEncoder to BoxToDelta

Author: qingqing01

paddle/fluid/operators/detection/bbox_util.h

@@ -0,0 +1,66 @@
+/* Copyright (c) 2018 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. */
+#pragma once
+#include "paddle/fluid/framework/eigen.h"
+#include "paddle/fluid/framework/tensor.h"
+
+namespace paddle {
+namespace operators {
+
+/*
+ * transform that computes target bounding-box regression deltas
+ * given proposal boxes and ground-truth boxes.
+ */
+template <typename T>
+inline void BoxToDelta(const int box_num, const framework::Tensor& ex_boxes,
+                       const framework::Tensor& gt_boxes, const T* weights,
+                       const bool normalized, framework::Tensor* box_delta) {
+  auto ex_boxes_et = framework::EigenTensor<T, 2>::From(ex_boxes);
+  auto gt_boxes_et = framework::EigenTensor<T, 2>::From(gt_boxes);
+  auto trg = framework::EigenTensor<T, 2>::From(*box_delta);
+  T ex_w, ex_h, ex_ctr_x, ex_ctr_y, gt_w, gt_h, gt_ctr_x, gt_ctr_y;
+  for (int64_t i = 0; i < box_num; ++i) {
+    ex_w = ex_boxes_et(i, 2) - ex_boxes_et(i, 0) + (normalized == false);
+    ex_h = ex_boxes_et(i, 3) - ex_boxes_et(i, 1) + (normalized == false);
+    ex_ctr_x = ex_boxes_et(i, 0) + 0.5 * ex_w;
+    ex_ctr_y = ex_boxes_et(i, 1) + 0.5 * ex_h;
+
+    gt_w = gt_boxes_et(i, 2) - gt_boxes_et(i, 0) + (normalized == false);
+    gt_h = gt_boxes_et(i, 3) - gt_boxes_et(i, 1) + (normalized == false);
+    gt_ctr_x = gt_boxes_et(i, 0) + 0.5 * gt_w;
+    gt_ctr_y = gt_boxes_et(i, 1) + 0.5 * gt_h;
+
+    trg(i, 0) = (gt_ctr_x - ex_ctr_x) / ex_w;
+    trg(i, 1) = (gt_ctr_y - ex_ctr_y) / ex_h;
+    trg(i, 2) = std::log(gt_w / ex_w);
+    trg(i, 3) = std::log(gt_h / ex_h);
+
+    if (weights) {
+      trg(i, 0) = trg(i, 0) / weights[0];
+      trg(i, 1) = trg(i, 1) / weights[1];
+      trg(i, 2) = trg(i, 2) / weights[2];
+      trg(i, 3) = trg(i, 3) / weights[3];
+    }
+  }
+}
+
+template <typename T>
+void Gather(const T* in, const int in_stride, const int* index, const int num,
+            T* out) {
+  const int stride_bytes = in_stride * sizeof(T);
+  for (int i = 0; i < num; ++i) {
+    int id = index[i];
+    memcpy(out + i * in_stride, in + id * in_stride, stride_bytes);
+  }
+}
+
+}  // namespace operators
+}  // namespace paddle

paddle/fluid/operators/detection/generate_proposal_labels_op.cc

@@ -14,6 +14,7 @@ limitations under the License. */
 #include <string>
 #include <vector>
 #include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/detection/bbox_util.h"
 #include "paddle/fluid/operators/gather.h"
 #include "paddle/fluid/operators/math/concat.h"
 #include "paddle/fluid/operators/math/math_function.h"
@@ -133,31 +134,6 @@ void BboxOverlaps(const Tensor& r_boxes, const Tensor& c_boxes,
   }
 }
 
-template <typename T>
-void BoxToDelta(int box_num, const Tensor& ex_boxes, const Tensor& gt_boxes,
-                const std::vector<float>& weights, Tensor* box_delta) {
-  auto ex_boxes_et = framework::EigenTensor<T, 2>::From(ex_boxes);
-  auto gt_boxes_et = framework::EigenTensor<T, 2>::From(gt_boxes);
-  auto box_delta_et = framework::EigenTensor<T, 2>::From(*box_delta);
-  T ex_w, ex_h, ex_ctr_x, ex_ctr_y, gt_w, gt_h, gt_ctr_x, gt_ctr_y;
-  for (int64_t i = 0; i < box_num; ++i) {
-    ex_w = ex_boxes_et(i, 2) - ex_boxes_et(i, 0) + 1;
-    ex_h = ex_boxes_et(i, 3) - ex_boxes_et(i, 1) + 1;
-    ex_ctr_x = ex_boxes_et(i, 0) + 0.5 * ex_w;
-    ex_ctr_y = ex_boxes_et(i, 1) + 0.5 * ex_h;
-
-    gt_w = gt_boxes_et(i, 2) - gt_boxes_et(i, 0) + 1;
-    gt_h = gt_boxes_et(i, 3) - gt_boxes_et(i, 1) + 1;
-    gt_ctr_x = gt_boxes_et(i, 0) + 0.5 * gt_w;
-    gt_ctr_y = gt_boxes_et(i, 1) + 0.5 * gt_h;
-
-    box_delta_et(i, 0) = (gt_ctr_x - ex_ctr_x) / ex_w / weights[0];
-    box_delta_et(i, 1) = (gt_ctr_y - ex_ctr_y) / ex_h / weights[1];
-    box_delta_et(i, 2) = log(gt_w / ex_w) / ex_w / weights[2];
-    box_delta_et(i, 3) = log(gt_h / ex_h) / ex_h / weights[3];
-  }
-}
-
 template <typename T>
 std::vector<std::vector<int>> SampleFgBgGt(
     const platform::CPUDeviceContext& context, Tensor* iou,
@@ -243,12 +219,11 @@ void GatherBoxesLabels(const platform::CPUDeviceContext& context,
                        Tensor* sampled_labels, Tensor* sampled_gts) {
   int fg_num = fg_inds.size();
   int bg_num = bg_inds.size();
-  int gt_num = fg_num + bg_num;
   Tensor fg_inds_t, bg_inds_t, gt_box_inds_t, gt_label_inds_t;
   int* fg_inds_data = fg_inds_t.mutable_data<int>({fg_num}, context.GetPlace());
   int* bg_inds_data = bg_inds_t.mutable_data<int>({bg_num}, context.GetPlace());
   int* gt_box_inds_data =
-      gt_box_inds_t.mutable_data<int>({gt_num}, context.GetPlace());
+      gt_box_inds_t.mutable_data<int>({fg_num}, context.GetPlace());
   int* gt_label_inds_data =
       gt_label_inds_t.mutable_data<int>({fg_num}, context.GetPlace());
   std::copy(fg_inds.begin(), fg_inds.end(), fg_inds_data);
@@ -303,18 +278,20 @@ std::vector<Tensor> SampleRoisForOneImage(
 
   // Gather boxes and labels
   Tensor sampled_boxes, sampled_labels, sampled_gts;
-  int boxes_num = fg_inds.size() + bg_inds.size();
+  int fg_num = fg_inds.size();
+  int bg_num = bg_inds.size();
+  int boxes_num = fg_num + bg_num;
   framework::DDim bbox_dim({boxes_num, kBoxDim});
   sampled_boxes.mutable_data<T>(bbox_dim, context.GetPlace());
   sampled_labels.mutable_data<int>({boxes_num}, context.GetPlace());
-  sampled_gts.mutable_data<T>(bbox_dim, context.GetPlace());
+  sampled_gts.mutable_data<T>({fg_num, kBoxDim}, context.GetPlace());
   GatherBoxesLabels<T>(context, boxes, *gt_boxes, *gt_classes, fg_inds, bg_inds,
                        gt_inds, &sampled_boxes, &sampled_labels, &sampled_gts);
 
   // Compute targets
   Tensor bbox_targets_single;
   bbox_targets_single.mutable_data<T>(bbox_dim, context.GetPlace());
-  BoxToDelta<T>(boxes_num, sampled_boxes, sampled_gts, bbox_reg_weights,
+  BoxToDelta<T>(fg_num, sampled_boxes, sampled_gts, nullptr, false,
                 &bbox_targets_single);
 
   // Scale rois
@@ -427,7 +404,7 @@ class GenerateProposalLabelsKernel : public framework::OpKernel<T> {
     auto rpn_rois_lod = rpn_rois->lod().back();
     auto gt_classes_lod = gt_classes->lod().back();
     auto gt_boxes_lod = gt_boxes->lod().back();
-    for (size_t i = 0; i < n; ++i) {
+    for (int i = 0; i < n; ++i) {
       Tensor rpn_rois_slice =
           rpn_rois->Slice(rpn_rois_lod[i], rpn_rois_lod[i + 1]);
       Tensor gt_classes_slice =

paddle/fluid/operators/detection/generate_proposals_op.cc

@@ -311,8 +311,7 @@ class GenerateProposalsKernel : public framework::OpKernel<T> {
 
     rpn_rois->mutable_data<T>({bbox_deltas->numel() / 4, 4},
                               context.GetPlace());
-    rpn_roi_probs->mutable_data<T>({scores->numel() / 4, 1},
-                                   context.GetPlace());
+    rpn_roi_probs->mutable_data<T>({scores->numel(), 1}, context.GetPlace());
 
     Tensor bbox_deltas_swap, scores_swap;
     bbox_deltas_swap.mutable_data<T>({num, h_bbox, w_bbox, c_bbox},
@@ -421,7 +420,7 @@ class GenerateProposalsKernel : public framework::OpKernel<T> {
     CPUGather<T>(ctx, proposals, keep, &bbox_sel);
     CPUGather<T>(ctx, scores_sel, keep, &scores_filter);
     if (nms_thresh <= 0) {
-      return std::make_pair(bbox_sel, scores_sel);
+      return std::make_pair(bbox_sel, scores_filter);
     }
 
     Tensor keep_nms = NMS<T>(ctx, &bbox_sel, &scores_filter, nms_thresh, eta);