Merge pull request #16073 from heavengate/yolov3_loss_imporve

Yolov3 loss: add mixup score and label smooth

paddle/fluid/API.spec

@@ -330,7 +330,7 @@ paddle.fluid.layers.generate_mask_labels (ArgSpec(args=['im_info', 'gt_classes',
 paddle.fluid.layers.iou_similarity (ArgSpec(args=['x', 'y', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '587845f60c5d97ffdf2dfd21da52eca1'))
 paddle.fluid.layers.box_coder (ArgSpec(args=['prior_box', 'prior_box_var', 'target_box', 'code_type', 'box_normalized', 'name', 'axis'], varargs=None, keywords=None, defaults=('encode_center_size', True, None, 0)), ('document', '032d0f4b7d8f6235ee5d91e473344f0e'))
 paddle.fluid.layers.polygon_box_transform (ArgSpec(args=['input', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '0e5ac2507723a0b5adec473f9556799b'))
-paddle.fluid.layers.yolov3_loss (ArgSpec(args=['x', 'gtbox', 'gtlabel', 'anchors', 'anchor_mask', 'class_num', 'ignore_thresh', 'downsample_ratio', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '991e934c3e09abf0edec7c9c978b4691'))
+paddle.fluid.layers.yolov3_loss (ArgSpec(args=['x', 'gtbox', 'gtlabel', 'anchors', 'anchor_mask', 'class_num', 'ignore_thresh', 'downsample_ratio', 'gtscore', 'use_label_smooth', 'name'], varargs=None, keywords=None, defaults=(None, True, None)), ('document', '57fa96922e42db8f064c3fb77f2255e8'))
 paddle.fluid.layers.box_clip (ArgSpec(args=['input', 'im_info', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '397e9e02b451d99c56e20f268fa03f2e'))
 paddle.fluid.layers.multiclass_nms (ArgSpec(args=['bboxes', 'scores', 'score_threshold', 'nms_top_k', 'keep_top_k', 'nms_threshold', 'normalized', 'nms_eta', 'background_label', 'name'], varargs=None, keywords=None, defaults=(0.3, True, 1.0, 0, None)), ('document', 'ca7d1107b6c5d2d6d8221039a220fde0'))
 paddle.fluid.layers.distribute_fpn_proposals (ArgSpec(args=['fpn_rois', 'min_level', 'max_level', 'refer_level', 'refer_scale', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '7bb011ec26bace2bc23235aa4a17647d'))

paddle/fluid/operators/detection/yolov3_loss_op.cc

@@ -10,6 +10,7 @@
    limitations under the License. */
 
 #include "paddle/fluid/operators/detection/yolov3_loss_op.h"
+#include <memory>
 #include "paddle/fluid/framework/op_registry.h"
 
 namespace paddle {
@@ -72,6 +73,18 @@ class Yolov3LossOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_GT(class_num, 0,
                       "Attr(class_num) should be an integer greater then 0.");
 
+    if (ctx->HasInput("GTScore")) {
+      auto dim_gtscore = ctx->GetInputDim("GTScore");
+      PADDLE_ENFORCE_EQ(dim_gtscore.size(), 2,
+                        "Input(GTScore) should be a 2-D tensor");
+      PADDLE_ENFORCE_EQ(
+          dim_gtscore[0], dim_gtbox[0],
+          "Input(GTBox) and Input(GTScore) dim[0] should be same");
+      PADDLE_ENFORCE_EQ(
+          dim_gtscore[1], dim_gtbox[1],
+          "Input(GTBox) and Input(GTScore) dim[1] should be same");
+    }
+
     std::vector<int64_t> dim_out({dim_x[0]});
     ctx->SetOutputDim("Loss", framework::make_ddim(dim_out));
 
@@ -112,6 +125,12 @@ class Yolov3LossOpMaker : public framework::OpProtoAndCheckerMaker {
              "This is a 2-D tensor with shape of [N, max_box_num], "
              "and each element should be an integer to indicate the "
              "box class id.");
+    AddInput("GTScore",
+             "The score of GTLabel, This is a 2-D tensor in same shape "
+             "GTLabel, and score values should in range (0, 1). This "
+             "input is for GTLabel score can be not 1.0 in image mixup "
+             "augmentation.")
+        .AsDispensable();
     AddOutput("Loss",
               "The output yolov3 loss tensor, "
               "This is a 1-D tensor with shape of [N]");
@@ -143,6 +162,9 @@ class Yolov3LossOpMaker : public framework::OpProtoAndCheckerMaker {
     AddAttr<float>("ignore_thresh",
                    "The ignore threshold to ignore confidence loss.")
         .SetDefault(0.7);
+    AddAttr<bool>("use_label_smooth",
+                  "Whether to use label smooth. Default True.")
+        .SetDefault(true);
     AddComment(R"DOC(
          This operator generates yolov3 loss based on given predict result and ground
          truth boxes.
@@ -204,6 +226,15 @@ class Yolov3LossOpMaker : public framework::OpProtoAndCheckerMaker {
          loss = (loss_{xy} + loss_{wh}) * weight_{box}
               + loss_{conf} + loss_{class}
          $$
+
+         While :attr:`use_label_smooth` is set to be :attr:`True`, the classification
+         target will be smoothed when calculating classification loss, target of 
+         positive samples will be smoothed to :math:`1.0 - 1.0 / class\_num` and target of
+         negetive samples will be smoothed to :math:`1.0 / class\_num`.
+
+         While :attr:`GTScore` is given, which means the mixup score of ground truth 
+         boxes, all losses incured by a ground truth box will be multiplied by its 
+         mixup score.
          )DOC");
   }
 };
@@ -240,6 +271,7 @@ class Yolov3LossGradMaker : public framework::SingleGradOpDescMaker {
     op->SetInput("X", Input("X"));
     op->SetInput("GTBox", Input("GTBox"));
     op->SetInput("GTLabel", Input("GTLabel"));
+    op->SetInput("GTScore", Input("GTScore"));
     op->SetInput(framework::GradVarName("Loss"), OutputGrad("Loss"));
     op->SetInput("ObjectnessMask", Output("ObjectnessMask"));
     op->SetInput("GTMatchMask", Output("GTMatchMask"));
@@ -249,6 +281,7 @@ class Yolov3LossGradMaker : public framework::SingleGradOpDescMaker {
     op->SetOutput(framework::GradVarName("X"), InputGrad("X"));
     op->SetOutput(framework::GradVarName("GTBox"), {});
     op->SetOutput(framework::GradVarName("GTLabel"), {});
+    op->SetOutput(framework::GradVarName("GTScore"), {});
     return std::unique_ptr<framework::OpDesc>(op);
   }
 };

paddle/fluid/operators/detection/yolov3_loss_op.h

@@ -37,8 +37,8 @@ static T SigmoidCrossEntropy(T x, T label) {
 }
 
 template <typename T>
-static T L2Loss(T x, T y) {
-  return 0.5 * (y - x) * (y - x);
+static T L1Loss(T x, T y) {
+  return std::abs(y - x);
 }
 
 template <typename T>
@@ -47,8 +47,8 @@ static T SigmoidCrossEntropyGrad(T x, T label) {
 }
 
 template <typename T>
-static T L2LossGrad(T x, T y) {
-  return x - y;
+static T L1LossGrad(T x, T y) {
+  return x > y ? 1.0 : -1.0;
 }
 
 static int GetMaskIndex(std::vector<int> mask, int val) {
@@ -121,47 +121,49 @@ template <typename T>
 static void CalcBoxLocationLoss(T* loss, const T* input, Box<T> gt,
                                 std::vector<int> anchors, int an_idx,
                                 int box_idx, int gi, int gj, int grid_size,
-                                int input_size, int stride) {
+                                int input_size, int stride, T score) {
   T tx = gt.x * grid_size - gi;
   T ty = gt.y * grid_size - gj;
   T tw = std::log(gt.w * input_size / anchors[2 * an_idx]);
   T th = std::log(gt.h * input_size / anchors[2 * an_idx + 1]);
 
-  T scale = (2.0 - gt.w * gt.h);
+  T scale = (2.0 - gt.w * gt.h) * score;
   loss[0] += SigmoidCrossEntropy<T>(input[box_idx], tx) * scale;
   loss[0] += SigmoidCrossEntropy<T>(input[box_idx + stride], ty) * scale;
-  loss[0] += L2Loss<T>(input[box_idx + 2 * stride], tw) * scale;
-  loss[0] += L2Loss<T>(input[box_idx + 3 * stride], th) * scale;
+  loss[0] += L1Loss<T>(input[box_idx + 2 * stride], tw) * scale;
+  loss[0] += L1Loss<T>(input[box_idx + 3 * stride], th) * scale;
 }
 
 template <typename T>
 static void CalcBoxLocationLossGrad(T* input_grad, const T loss, const T* input,
                                     Box<T> gt, std::vector<int> anchors,
                                     int an_idx, int box_idx, int gi, int gj,
-                                    int grid_size, int input_size, int stride) {
+                                    int grid_size, int input_size, int stride,
+                                    T score) {
   T tx = gt.x * grid_size - gi;
   T ty = gt.y * grid_size - gj;
   T tw = std::log(gt.w * input_size / anchors[2 * an_idx]);
   T th = std::log(gt.h * input_size / anchors[2 * an_idx + 1]);
 
-  T scale = (2.0 - gt.w * gt.h);
+  T scale = (2.0 - gt.w * gt.h) * score;
   input_grad[box_idx] =
       SigmoidCrossEntropyGrad<T>(input[box_idx], tx) * scale * loss;
   input_grad[box_idx + stride] =
       SigmoidCrossEntropyGrad<T>(input[box_idx + stride], ty) * scale * loss;
   input_grad[box_idx + 2 * stride] =
-      L2LossGrad<T>(input[box_idx + 2 * stride], tw) * scale * loss;
+      L1LossGrad<T>(input[box_idx + 2 * stride], tw) * scale * loss;
   input_grad[box_idx + 3 * stride] =
-      L2LossGrad<T>(input[box_idx + 3 * stride], th) * scale * loss;
+      L1LossGrad<T>(input[box_idx + 3 * stride], th) * scale * loss;
 }
 
 template <typename T>
 static inline void CalcLabelLoss(T* loss, const T* input, const int index,
                                  const int label, const int class_num,
-                                 const int stride) {
+                                 const int stride, const T pos, const T neg,
+                                 T score) {
   for (int i = 0; i < class_num; i++) {
     T pred = input[index + i * stride];
-    loss[0] += SigmoidCrossEntropy<T>(pred, (i == label) ? 1.0 : 0.0);
+    loss[0] += SigmoidCrossEntropy<T>(pred, (i == label) ? pos : neg) * score;
   }
 }
 
@@ -169,11 +171,13 @@ template <typename T>
 static inline void CalcLabelLossGrad(T* input_grad, const T loss,
                                      const T* input, const int index,
                                      const int label, const int class_num,
-                                     const int stride) {
+                                     const int stride, const T pos, const T neg,
+                                     T score) {
   for (int i = 0; i < class_num; i++) {
     T pred = input[index + i * stride];
     input_grad[index + i * stride] =
-        SigmoidCrossEntropyGrad<T>(pred, (i == label) ? 1.0 : 0.0) * loss;
+        SigmoidCrossEntropyGrad<T>(pred, (i == label) ? pos : neg) * score *
+        loss;
   }
 }
 
@@ -188,8 +192,8 @@ static inline void CalcObjnessLoss(T* loss, const T* input, const T* objness,
         for (int l = 0; l < w; l++) {
           T obj = objness[k * w + l];
           if (obj > 1e-5) {
-            // positive sample: obj = 1
-            loss[i] += SigmoidCrossEntropy<T>(input[k * w + l], 1.0);
+            // positive sample: obj = mixup score
+            loss[i] += SigmoidCrossEntropy<T>(input[k * w + l], 1.0) * obj;
           } else if (obj > -0.5) {
             // negetive sample: obj = 0
             loss[i] += SigmoidCrossEntropy<T>(input[k * w + l], 0.0);
@@ -215,7 +219,8 @@ static inline void CalcObjnessLossGrad(T* input_grad, const T* loss,
           T obj = objness[k * w + l];
           if (obj > 1e-5) {
             input_grad[k * w + l] =
-                SigmoidCrossEntropyGrad<T>(input[k * w + l], 1.0) * loss[i];
+                SigmoidCrossEntropyGrad<T>(input[k * w + l], 1.0) * obj *
+                loss[i];
           } else if (obj > -0.5) {
             input_grad[k * w + l] =
                 SigmoidCrossEntropyGrad<T>(input[k * w + l], 0.0) * loss[i];
@@ -252,6 +257,7 @@ class Yolov3LossKernel : public framework::OpKernel<T> {
     auto* input = ctx.Input<Tensor>("X");
     auto* gt_box = ctx.Input<Tensor>("GTBox");
     auto* gt_label = ctx.Input<Tensor>("GTLabel");
+    auto* gt_score = ctx.Input<Tensor>("GTScore");
     auto* loss = ctx.Output<Tensor>("Loss");
     auto* objness_mask = ctx.Output<Tensor>("ObjectnessMask");
     auto* gt_match_mask = ctx.Output<Tensor>("GTMatchMask");
@@ -260,6 +266,7 @@ class Yolov3LossKernel : public framework::OpKernel<T> {
     int class_num = ctx.Attr<int>("class_num");
     float ignore_thresh = ctx.Attr<float>("ignore_thresh");
     int downsample_ratio = ctx.Attr<int>("downsample_ratio");
+    bool use_label_smooth = ctx.Attr<bool>("use_label_smooth");
 
     const int n = input->dims()[0];
     const int h = input->dims()[2];
@@ -272,6 +279,13 @@ class Yolov3LossKernel : public framework::OpKernel<T> {
     const int stride = h * w;
     const int an_stride = (class_num + 5) * stride;
 
+    T label_pos = 1.0;
+    T label_neg = 0.0;
+    if (use_label_smooth) {
+      label_pos = 1.0 - 1.0 / static_cast<T>(class_num);
+      label_neg = 1.0 / static_cast<T>(class_num);
+    }
+
     const T* input_data = input->data<T>();
     const T* gt_box_data = gt_box->data<T>();
     const int* gt_label_data = gt_label->data<int>();
@@ -283,6 +297,19 @@ class Yolov3LossKernel : public framework::OpKernel<T> {
     int* gt_match_mask_data =
         gt_match_mask->mutable_data<int>({n, b}, ctx.GetPlace());
 
+    const T* gt_score_data;
+    if (!gt_score) {
+      Tensor gtscore;
+      gtscore.mutable_data<T>({n, b}, ctx.GetPlace());
+      math::SetConstant<platform::CPUDeviceContext, T>()(
+          ctx.template device_context<platform::CPUDeviceContext>(), &gtscore,
+          static_cast<T>(1.0));
+      gt_score = &gtscore;
+      gt_score_data = gtscore.data<T>();
+    } else {
+      gt_score_data = gt_score->data<T>();
+    }
+
     // calc valid gt box mask, avoid calc duplicately in following code
     Tensor gt_valid_mask;
     bool* gt_valid_mask_data =
@@ -355,19 +382,20 @@ class Yolov3LossKernel : public framework::OpKernel<T> {
         int mask_idx = GetMaskIndex(anchor_mask, best_n);
         gt_match_mask_data[i * b + t] = mask_idx;
         if (mask_idx >= 0) {
+          T score = gt_score_data[i * b + t];
           int box_idx = GetEntryIndex(i, mask_idx, gj * w + gi, mask_num,
                                       an_stride, stride, 0);
           CalcBoxLocationLoss<T>(loss_data + i, input_data, gt, anchors, best_n,
-                                 box_idx, gi, gj, h, input_size, stride);
+                                 box_idx, gi, gj, h, input_size, stride, score);
 
           int obj_idx = (i * mask_num + mask_idx) * stride + gj * w + gi;
-          obj_mask_data[obj_idx] = 1.0;
+          obj_mask_data[obj_idx] = score;
 
           int label = gt_label_data[i * b + t];
           int label_idx = GetEntryIndex(i, mask_idx, gj * w + gi, mask_num,
                                         an_stride, stride, 5);
           CalcLabelLoss<T>(loss_data + i, input_data, label_idx, label,
-                           class_num, stride);
+                           class_num, stride, label_pos, label_neg, score);
         }
       }
     }
@@ -384,6 +412,7 @@ class Yolov3LossGradKernel : public framework::OpKernel<T> {
     auto* input = ctx.Input<Tensor>("X");
     auto* gt_box = ctx.Input<Tensor>("GTBox");
     auto* gt_label = ctx.Input<Tensor>("GTLabel");
+    auto* gt_score = ctx.Input<Tensor>("GTScore");
     auto* input_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
     auto* loss_grad = ctx.Input<Tensor>(framework::GradVarName("Loss"));
     auto* objness_mask = ctx.Input<Tensor>("ObjectnessMask");
@@ -392,6 +421,7 @@ class Yolov3LossGradKernel : public framework::OpKernel<T> {
     auto anchor_mask = ctx.Attr<std::vector<int>>("anchor_mask");
     int class_num = ctx.Attr<int>("class_num");
     int downsample_ratio = ctx.Attr<int>("downsample_ratio");
+    bool use_label_smooth = ctx.Attr<bool>("use_label_smooth");
 
     const int n = input_grad->dims()[0];
     const int c = input_grad->dims()[1];
@@ -404,6 +434,13 @@ class Yolov3LossGradKernel : public framework::OpKernel<T> {
     const int stride = h * w;
     const int an_stride = (class_num + 5) * stride;
 
+    T label_pos = 1.0;
+    T label_neg = 0.0;
+    if (use_label_smooth) {
+      label_pos = 1.0 - 1.0 / static_cast<T>(class_num);
+      label_neg = 1.0 / static_cast<T>(class_num);
+    }
+
     const T* input_data = input->data<T>();
     const T* gt_box_data = gt_box->data<T>();
     const int* gt_label_data = gt_label->data<int>();
@@ -414,25 +451,41 @@ class Yolov3LossGradKernel : public framework::OpKernel<T> {
         input_grad->mutable_data<T>({n, c, h, w}, ctx.GetPlace());
     memset(input_grad_data, 0, input_grad->numel() * sizeof(T));
 
+    const T* gt_score_data;
+    if (!gt_score) {
+      Tensor gtscore;
+      gtscore.mutable_data<T>({n, b}, ctx.GetPlace());
+      math::SetConstant<platform::CPUDeviceContext, T>()(
+          ctx.template device_context<platform::CPUDeviceContext>(), &gtscore,
+          static_cast<T>(1.0));
+      gt_score = &gtscore;
+      gt_score_data = gtscore.data<T>();
+    } else {
+      gt_score_data = gt_score->data<T>();
+    }
+
     for (int i = 0; i < n; i++) {
       for (int t = 0; t < b; t++) {
         int mask_idx = gt_match_mask_data[i * b + t];
         if (mask_idx >= 0) {
+          T score = gt_score_data[i * b + t];
           Box<T> gt = GetGtBox(gt_box_data, i, b, t);
           int gi = static_cast<int>(gt.x * w);
           int gj = static_cast<int>(gt.y * h);
 
           int box_idx = GetEntryIndex(i, mask_idx, gj * w + gi, mask_num,
                                       an_stride, stride, 0);
-          CalcBoxLocationLossGrad<T>(
-              input_grad_data, loss_grad_data[i], input_data, gt, anchors,
-              anchor_mask[mask_idx], box_idx, gi, gj, h, input_size, stride);
+          CalcBoxLocationLossGrad<T>(input_grad_data, loss_grad_data[i],
+                                     input_data, gt, anchors,
+                                     anchor_mask[mask_idx], box_idx, gi, gj, h,
+                                     input_size, stride, score);
 
           int label = gt_label_data[i * b + t];
           int label_idx = GetEntryIndex(i, mask_idx, gj * w + gi, mask_num,
                                         an_stride, stride, 5);
           CalcLabelLossGrad<T>(input_grad_data, loss_grad_data[i], input_data,
-                               label_idx, label, class_num, stride);
+                               label_idx, label, class_num, stride, label_pos,
+                               label_neg, score);
         }
       }
     }

python/paddle/fluid/layers/detection.py

@@ -515,6 +515,8 @@ def yolov3_loss(x,
                 class_num,
                 ignore_thresh,
                 downsample_ratio,
+                gtscore=None,
+                use_label_smooth=True,
                 name=None):
     """
     ${comment}
@@ -533,28 +535,35 @@ def yolov3_loss(x,
         class_num (int): ${class_num_comment}
         ignore_thresh (float): ${ignore_thresh_comment}
         downsample_ratio (int): ${downsample_ratio_comment}
-        name (string): the name of yolov3 loss
+        name (string): the name of yolov3 loss. Default None.
+        gtscore (Variable): mixup score of ground truth boxes, shoud be in shape
+                            of [N, B]. Default None.
+        use_label_smooth (bool): ${use_label_smooth_comment}
 
     Returns:
-        Variable: A 1-D tensor with shape [1], the value of yolov3 loss
+        Variable: A 1-D tensor with shape [N], the value of yolov3 loss
 
     Raises:
         TypeError: Input x of yolov3_loss must be Variable
-        TypeError: Input gtbox of yolov3_loss must be Variable"
-        TypeError: Input gtlabel of yolov3_loss must be Variable"
+        TypeError: Input gtbox of yolov3_loss must be Variable
+        TypeError: Input gtlabel of yolov3_loss must be Variable
+        TypeError: Input gtscore of yolov3_loss must be None or Variable
         TypeError: Attr anchors of yolov3_loss must be list or tuple
         TypeError: Attr class_num of yolov3_loss must be an integer
         TypeError: Attr ignore_thresh of yolov3_loss must be a float number
+        TypeError: Attr use_label_smooth of yolov3_loss must be a bool value
 
     Examples:
       .. code-block:: python
 
           x = fluid.layers.data(name='x', shape=[255, 13, 13], dtype='float32')
-          gtbox = fluid.layers.data(name='gtbox', shape=[6, 5], dtype='float32')
-          gtlabel = fluid.layers.data(name='gtlabel', shape=[6, 1], dtype='int32')
+          gtbox = fluid.layers.data(name='gtbox', shape=[6, 4], dtype='float32')
+          gtlabel = fluid.layers.data(name='gtlabel', shape=[6], dtype='int32')
+          gtscore = fluid.layers.data(name='gtscore', shape=[6], dtype='float32')
           anchors = [10, 13, 16, 30, 33, 23, 30, 61, 62, 45, 59, 119, 116, 90, 156, 198, 373, 326]
           anchor_mask = [0, 1, 2]
-          loss = fluid.layers.yolov3_loss(x=x, gtbox=gtbox, gtlabel=gtlabel, anchors=anchors, 
+          loss = fluid.layers.yolov3_loss(x=x, gtbox=gtbox, gtlabel=gtlabel,
+                                          gtscore=gtscore, anchors=anchors, 
                                           anchor_mask=anchor_mask, class_num=80,
                                           ignore_thresh=0.7, downsample_ratio=32)
     """
@@ -566,6 +575,8 @@ def yolov3_loss(x,
         raise TypeError("Input gtbox of yolov3_loss must be Variable")
     if not isinstance(gtlabel, Variable):
         raise TypeError("Input gtlabel of yolov3_loss must be Variable")
+    if gtscore is not None and not isinstance(gtscore, Variable):
+        raise TypeError("Input gtscore of yolov3_loss must be Variable")
     if not isinstance(anchors, list) and not isinstance(anchors, tuple):
         raise TypeError("Attr anchors of yolov3_loss must be list or tuple")
     if not isinstance(anchor_mask, list) and not isinstance(anchor_mask, tuple):
@@ -575,6 +586,9 @@ def yolov3_loss(x,
     if not isinstance(ignore_thresh, float):
         raise TypeError(
             "Attr ignore_thresh of yolov3_loss must be a float number")
+    if not isinstance(use_label_smooth, bool):
+        raise TypeError(
+            "Attr use_label_smooth of yolov3_loss must be a bool value")
 
     if name is None:
         loss = helper.create_variable_for_type_inference(dtype=x.dtype)
@@ -585,21 +599,26 @@ def yolov3_loss(x,
     objectness_mask = helper.create_variable_for_type_inference(dtype='int32')
     gt_match_mask = helper.create_variable_for_type_inference(dtype='int32')
 
+    inputs = {
+        "X": x,
+        "GTBox": gtbox,
+        "GTLabel": gtlabel,
+    }
+    if gtscore:
+        inputs["GTScore"] = gtscore
+
     attrs = {
         "anchors": anchors,
         "anchor_mask": anchor_mask,
         "class_num": class_num,
         "ignore_thresh": ignore_thresh,
         "downsample_ratio": downsample_ratio,
+        "use_label_smooth": use_label_smooth,
     }
 
     helper.append_op(
         type='yolov3_loss',
-        inputs={
-            "X": x,
-            "GTBox": gtbox,
-            "GTLabel": gtlabel,
-        },
+        inputs=inputs,
         outputs={
             'Loss': loss,
             'ObjectnessMask': objectness_mask,

python/paddle/fluid/tests/test_detection.py

@@ -476,8 +476,16 @@ class TestYoloDetection(unittest.TestCase):
             x = layers.data(name='x', shape=[30, 7, 7], dtype='float32')
             gtbox = layers.data(name='gtbox', shape=[10, 4], dtype='float32')
             gtlabel = layers.data(name='gtlabel', shape=[10], dtype='int32')
-            loss = layers.yolov3_loss(x, gtbox, gtlabel, [10, 13, 30, 13],
-                                      [0, 1], 10, 0.7, 32)
+            gtscore = layers.data(name='gtscore', shape=[10], dtype='float32')
+            loss = layers.yolov3_loss(
+                x,
+                gtbox,
+                gtlabel, [10, 13, 30, 13], [0, 1],
+                10,
+                0.7,
+                32,
+                gtscore=gtscore,
+                use_label_smooth=False)
 
             self.assertIsNotNone(loss)
 

python/paddle/fluid/tests/unittests/test_yolov3_loss_op.py

@@ -23,8 +23,8 @@ from op_test import OpTest
 from paddle.fluid import core
 
 
-def l2loss(x, y):
-    return 0.5 * (y - x) * (y - x)
+def l1loss(x, y):
+    return abs(x - y)
 
 
 def sce(x, label):
@@ -66,7 +66,7 @@ def batch_xywh_box_iou(box1, box2):
     return inter_area / union
 
 
-def YOLOv3Loss(x, gtbox, gtlabel, attrs):
+def YOLOv3Loss(x, gtbox, gtlabel, gtscore, attrs):
     n, c, h, w = x.shape
     b = gtbox.shape[1]
     anchors = attrs['anchors']
@@ -75,21 +75,21 @@ def YOLOv3Loss(x, gtbox, gtlabel, attrs):
     mask_num = len(anchor_mask)
     class_num = attrs["class_num"]
     ignore_thresh = attrs['ignore_thresh']
-    downsample = attrs['downsample']
-    input_size = downsample * h
+    downsample_ratio = attrs['downsample_ratio']
+    use_label_smooth = attrs['use_label_smooth']
+    input_size = downsample_ratio * h
     x = x.reshape((n, mask_num, 5 + class_num, h, w)).transpose((0, 1, 3, 4, 2))
     loss = np.zeros((n)).astype('float32')
 
+    label_pos = 1.0 - 1.0 / class_num if use_label_smooth else 1.0
+    label_neg = 1.0 / class_num if use_label_smooth else 0.0
+
     pred_box = x[:, :, :, :, :4].copy()
     grid_x = np.tile(np.arange(w).reshape((1, w)), (h, 1))
     grid_y = np.tile(np.arange(h).reshape((h, 1)), (1, w))
     pred_box[:, :, :, :, 0] = (grid_x + sigmoid(pred_box[:, :, :, :, 0])) / w
     pred_box[:, :, :, :, 1] = (grid_y + sigmoid(pred_box[:, :, :, :, 1])) / h
 
-    x[:, :, :, :, 5:] = np.where(x[:, :, :, :, 5:] < -0.5, x[:, :, :, :, 5:],
-                                 np.ones_like(x[:, :, :, :, 5:]) * 1.0 /
-                                 class_num)
-
     mask_anchors = []
     for m in anchor_mask:
         mask_anchors.append((anchors[2 * m], anchors[2 * m + 1]))
@@ -138,21 +138,22 @@ def YOLOv3Loss(x, gtbox, gtlabel, attrs):
             ty = gtbox[i, j, 1] * w - gj
             tw = np.log(gtbox[i, j, 2] * input_size / mask_anchors[an_idx][0])
             th = np.log(gtbox[i, j, 3] * input_size / mask_anchors[an_idx][1])
-            scale = (2.0 - gtbox[i, j, 2] * gtbox[i, j, 3])
+            scale = (2.0 - gtbox[i, j, 2] * gtbox[i, j, 3]) * gtscore[i, j]
             loss[i] += sce(x[i, an_idx, gj, gi, 0], tx) * scale
             loss[i] += sce(x[i, an_idx, gj, gi, 1], ty) * scale
-            loss[i] += l2loss(x[i, an_idx, gj, gi, 2], tw) * scale
-            loss[i] += l2loss(x[i, an_idx, gj, gi, 3], th) * scale
+            loss[i] += l1loss(x[i, an_idx, gj, gi, 2], tw) * scale
+            loss[i] += l1loss(x[i, an_idx, gj, gi, 3], th) * scale
 
-            objness[i, an_idx * h * w + gj * w + gi] = 1.0
+            objness[i, an_idx * h * w + gj * w + gi] = gtscore[i, j]
 
             for label_idx in range(class_num):
-                loss[i] += sce(x[i, an_idx, gj, gi, 5 + label_idx],
-                               float(label_idx == gtlabel[i, j]))
+                loss[i] += sce(x[i, an_idx, gj, gi, 5 + label_idx], label_pos
+                               if label_idx == gtlabel[i, j] else
+                               label_neg) * gtscore[i, j]
 
         for j in range(mask_num * h * w):
             if objness[i, j] > 0:
-                loss[i] += sce(pred_obj[i, j], 1.0)
+                loss[i] += sce(pred_obj[i, j], 1.0) * objness[i, j]
             elif objness[i, j] == 0:
                 loss[i] += sce(pred_obj[i, j], 0.0)
 
@@ -176,7 +177,8 @@ class TestYolov3LossOp(OpTest):
             "anchor_mask": self.anchor_mask,
             "class_num": self.class_num,
             "ignore_thresh": self.ignore_thresh,
-            "downsample": self.downsample,
+            "downsample_ratio": self.downsample_ratio,
+            "use_label_smooth": self.use_label_smooth,
         }
 
         self.inputs = {
@@ -184,7 +186,14 @@ class TestYolov3LossOp(OpTest):
             'GTBox': gtbox.astype('float32'),
             'GTLabel': gtlabel.astype('int32'),
         }
-        loss, objness, gt_matches = YOLOv3Loss(x, gtbox, gtlabel, self.attrs)
+
+        gtscore = np.ones(self.gtbox_shape[:2]).astype('float32')
+        if self.gtscore:
+            gtscore = np.random.random(self.gtbox_shape[:2]).astype('float32')
+            self.inputs['GTScore'] = gtscore
+
+        loss, objness, gt_matches = YOLOv3Loss(x, gtbox, gtlabel, gtscore,
+                                               self.attrs)
         self.outputs = {
             'Loss': loss,
             'ObjectnessMask': objness,
@@ -193,24 +202,57 @@ class TestYolov3LossOp(OpTest):
 
     def test_check_output(self):
         place = core.CPUPlace()
-        self.check_output_with_place(place, atol=1e-3)
+        self.check_output_with_place(place, atol=2e-3)
 
     def test_check_grad_ignore_gtbox(self):
         place = core.CPUPlace()
-        self.check_grad_with_place(
-            place, ['X'],
-            'Loss',
-            no_grad_set=set(["GTBox", "GTLabel"]),
-            max_relative_error=0.3)
+        self.check_grad_with_place(place, ['X'], 'Loss', max_relative_error=0.2)
+
+    def initTestCase(self):
+        self.anchors = [
+            10, 13, 16, 30, 33, 23, 30, 61, 62, 45, 59, 119, 116, 90, 156, 198,
+            373, 326
+        ]
+        self.anchor_mask = [0, 1, 2]
+        self.class_num = 5
+        self.ignore_thresh = 0.7
+        self.downsample_ratio = 32
+        self.x_shape = (3, len(self.anchor_mask) * (5 + self.class_num), 5, 5)
+        self.gtbox_shape = (3, 5, 4)
+        self.gtscore = True
+        self.use_label_smooth = True
+
+
+class TestYolov3LossWithoutLabelSmooth(TestYolov3LossOp):
+    def initTestCase(self):
+        self.anchors = [
+            10, 13, 16, 30, 33, 23, 30, 61, 62, 45, 59, 119, 116, 90, 156, 198,
+            373, 326
+        ]
+        self.anchor_mask = [0, 1, 2]
+        self.class_num = 5
+        self.ignore_thresh = 0.7
+        self.downsample_ratio = 32
+        self.x_shape = (3, len(self.anchor_mask) * (5 + self.class_num), 5, 5)
+        self.gtbox_shape = (3, 5, 4)
+        self.gtscore = True
+        self.use_label_smooth = False
+
 
+class TestYolov3LossNoGTScore(TestYolov3LossOp):
     def initTestCase(self):
-        self.anchors = [10, 13, 16, 30, 33, 23]
-        self.anchor_mask = [1, 2]
+        self.anchors = [
+            10, 13, 16, 30, 33, 23, 30, 61, 62, 45, 59, 119, 116, 90, 156, 198,
+            373, 326
+        ]
+        self.anchor_mask = [0, 1, 2]
         self.class_num = 5
-        self.ignore_thresh = 0.5
-        self.downsample = 32
+        self.ignore_thresh = 0.7
+        self.downsample_ratio = 32
         self.x_shape = (3, len(self.anchor_mask) * (5 + self.class_num), 5, 5)
         self.gtbox_shape = (3, 5, 4)
+        self.gtscore = False
+        self.use_label_smooth = True
 
 
 if __name__ == "__main__":