Local response normalize. (#4426)

Add local response normalize

paddle/operators/lrn_op.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+   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. */
+
+#include "paddle/operators/lrn_op.h"
+
+namespace paddle {
+namespace operators {
+
+using framework::Tensor;
+
+class LRNOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+ protected:
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"), "Input(X) of LRNOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("Out"),
+                   "Output(Out) of LRNOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("MidOut"),
+                   "MidOut(Out) of LRNOp should not be null.");
+
+    auto x_dim = ctx->GetInputDim("X");
+    PADDLE_ENFORCE_EQ(x_dim.size(), 4, "Input(X)'rank of LRNOp should be 4.");
+
+    ctx->SetOutputDim("Out", x_dim);
+    ctx->SetOutputDim("MidOut", x_dim);
+    ctx->ShareLoD("X", /*->*/ "Out");
+  }
+};
+
+template <typename T>
+class LRNOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  LRNOpMaker(framework::OpProto* proto, framework::OpAttrChecker* op_checker)
+      : OpProtoAndCheckerMaker(proto, op_checker) {
+    AddInput("X", R"DOC(
+ (Tensor) The input of LRN operator. It must be a 4D tenor with NCHW format.
+ )DOC");
+
+    AddOutput("Out",
+              "(Tensor) The output of LRN operator, which is also the 4D "
+              "tensor with NCHW format.");
+    AddOutput("MidOut", R"Doc(
+(Tensor)Middle result of lrn op.It's computed in forward process 
+and also used in backward process.
+    )Doc");
+
+    AddAttr<int>("n", R"DOC(
+(int, default 5)n is “adjacent” kernel maps at the same spatial position.
+        )DOC")
+        .SetDefault(5)
+        .GreaterThan(0);
+
+    AddAttr<T>("k", R"DOC(
+(float, default 2.0)k is the bias.
+        )DOC")
+        .SetDefault(2.0)
+        .GreaterThan(0.0);
+
+    AddAttr<T>("alpha", R"DOC(
+(float, default 0.0001)alpha is the scale number.
+        )DOC")
+        .SetDefault(0.0001)
+        .GreaterThan(0.0);
+
+    AddAttr<T>("beta", R"DOC(
+(float, default 0.75)beta is the power number.
+        )DOC")
+        .SetDefault(0.75)
+        .GreaterThan(0.0);
+
+    AddComment(R"DOC(
+ Local Response Normalization.
+
+ This Function comes from the paper
+ "ImageNet Classification with Deep Convolutional Neural Networks".
+
+ The original formula is:
+
+                                Input(i, x, y)
+ Output(i, x, y) = ----------------------------------------------
+                                 -- upper
+                    (k + alpha * >  (Input(j, x, y))^2) ^ (beta)
+                                 -- j = lower
+
+ upper is `min(C, c + n/2)`
+ lower if `max(0, c - n/2)`
+
+ Function implementation:
+
+ inputs and outpus is NCHW format, while input.shape.ndims() is equal 4.
+ And the meaning of each dimension(0-3) is respectively batch size,
+ feature maps, rows and columns.
+
+ Input and Output in the above formula is for each map(i) of one image, and
+ Input(i, x, y), Output(i, x, y) represents an element in an image.
+
+ C is the number of feature maps of one image, and n is a hyper-parameters
+ is configured when Function is initialized. The sum in the denominator
+ is the sum of the same position in the neighboring maps.
+    )DOC");
+  }
+};
+
+class LRNOpGrad : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+ protected:
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"), "Input(X) should not be null");
+    PADDLE_ENFORCE(ctx->HasInput(framework::GradVarName("MidOut")),
+                   "Input(MidOut@GRAD) should not be null");
+    PADDLE_ENFORCE(ctx->HasInput(framework::GradVarName("Out")),
+                   "Input(Out@GRAD) should not be null");
+
+    auto x_dims = ctx->GetInputDim("X");
+    ctx->SetOutputDim(framework::GradVarName("X"), x_dims);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP(lrn, ops::LRNOp, ops::LRNOpMaker<float>, lrn_grad, ops::LRNOpGrad);
+REGISTER_OP_CPU_KERNEL(lrn, ops::LRNKernel<paddle::platform::CPUPlace, float>);
+REGISTER_OP_CPU_KERNEL(lrn_grad,
+                       ops::LRNGradKernel<paddle::platform::CPUPlace, float>);

paddle/operators/lrn_op.cu

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+   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. */
+
+#define EIGEN_USE_GPU
+#include "paddle/operators/lrn_op.h"
+
+namespace ops = paddle::operators;
+
+REGISTER_OP_GPU_KERNEL(lrn, ops::LRNKernel<paddle::platform::GPUPlace, float>);
+REGISTER_OP_GPU_KERNEL(lrn_grad,
+                       ops::LRNGradKernel<paddle::platform::GPUPlace, float>);

paddle/operators/lrn_op.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+   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/framework/eigen.h"
+#include "paddle/framework/op_registry.h"
+#include "paddle/operators/math/math_function.h"
+
+namespace paddle {
+namespace operators {
+
+template <typename Place, typename T>
+class LRNKernel : public framework::OpKernel<T> {
+ public:
+  using Tensor = framework::Tensor;
+
+  // f(x) = x * ( k + alpha * SUM((x)^2) )^(-beta)
+  // x represents inputs
+  // f(x) represents outputs
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    // input
+    const Tensor* x = ctx.Input<Tensor>("X");
+    auto x_dims = x->dims();
+
+    // NCHW
+    int N = x_dims[0];
+    int C = x_dims[1];
+    int H = x_dims[2];
+    int W = x_dims[3];
+
+    Tensor* out = ctx.Output<Tensor>("Out");
+    out->mutable_data<T>(ctx.GetPlace());
+
+    // MidOut save the intermediate result for backward
+    Tensor* mid = ctx.Output<Tensor>("MidOut");
+    mid->mutable_data<T>(ctx.GetPlace());
+
+    int n = ctx.Attr<int>("n");
+    T alpha = ctx.Attr<float>("alpha");
+    T beta = ctx.Attr<float>("beta");
+    T k = ctx.Attr<float>("k");
+
+    PADDLE_ENFORCE(n > 0, "n should >= 0");
+    PADDLE_ENFORCE(alpha >= 0.0, "alpha should >= 0.0");
+    PADDLE_ENFORCE(beta >= 0.0, "beta should >= 0.0");
+    PADDLE_ENFORCE(k >= 0.0, "k should >= 0.0");
+
+    auto x_v = framework::EigenVector<T>::Flatten(*x);
+
+    const int start = -(n - 1) / 2;
+    const int end = start + n;
+
+    auto e_mid = framework::EigenTensor<T, 4>::From(*mid);
+    e_mid.device(ctx.GetEigenDevice<Place>()) = e_mid.constant(k);
+
+    auto e_x = framework::EigenTensor<T, 4>::From(*x);
+    for (int m = 0; m < N; m++) {
+      for (int i = 0; i < C; i++) {
+        for (int c = start; c <= end; c++) {
+          int ch = i + c;
+          if (ch >= 0 && ch < C) {
+            auto s = e_mid.slice(Eigen::array<int, 4>({{m, i, 0, 0}}),
+                                 Eigen::array<int, 4>({{1, 1, H, W}}));
+
+            auto r = e_x.slice(Eigen::array<int, 4>({{m, ch, 0, 0}}),
+                               Eigen::array<int, 4>({{1, 1, H, W}}));
+
+            s.device(ctx.GetEigenDevice<Place>()) += alpha * r.square();
+          }
+        }
+      }
+    }
+
+    auto out_e = framework::EigenVector<T>::Flatten(*out);
+    out_e.device(ctx.GetEigenDevice<Place>()) =
+        x_v * e_mid.reshape(Eigen::DSizes<int, 1>(e_mid.size())).pow(-beta);
+  }
+};
+
+/**
+ * \brief Backward calculation for normalization with across maps.
+ *
+ * Function implementation:
+ *
+ * The implementation of this Function is derived from the
+ * CrossMapNormalFunc implementation.
+ *
+ * InputGrad = OutputGrad * denoms ^ (-beta)
+ *    -- upper
+ *  + > (OutputGrad * OutputValue * (-2 * alpha * beta) / MidOut) * InputValue
+ *    -- lower
+ *
+ * The data of inputs/outputs format is the same as the forward interface
+ * and is NCHW.
+ *
+ * The upper and lower is the same as forward. The logic of the sum
+ * is also the same as forward.
+ */
+template <typename Place, typename T>
+class LRNGradKernel : public framework::OpKernel<T> {
+ public:
+  using Tensor = framework::Tensor;
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    const Tensor* x = ctx.Input<Tensor>("X");
+    const Tensor* out = ctx.Input<Tensor>("Out");
+    const Tensor* out_g = ctx.Input<Tensor>(framework::GradVarName("Out"));
+    const Tensor* mid = ctx.Input<Tensor>("MidOut");
+
+    auto x_g = ctx.Output<Tensor>(framework::GradVarName("X"));
+    x_g->mutable_data<T>(ctx.GetPlace());
+
+    auto x_g_e = framework::EigenVector<T>::Flatten(*x_g);
+    x_g_e.device(ctx.GetEigenDevice<Place>()) = x_g_e.constant(0.0);
+
+    auto x_dims = x->dims();
+    int N = x_dims[0];
+    int C = x_dims[1];
+    int H = x_dims[2];
+    int W = x_dims[3];
+
+    int n = ctx.Attr<int>("n");
+    T alpha = ctx.Attr<T>("alpha");
+    T beta = ctx.Attr<T>("beta");
+    T ratio = -2 * alpha * beta;
+
+    auto e_x = framework::EigenTensor<T, 4>::From(*x);
+    auto e_x_g = framework::EigenTensor<T, 4>::From(*x_g);
+    auto e_out = framework::EigenTensor<T, 4>::From(*out);
+    auto e_out_g = framework::EigenTensor<T, 4>::From(*out_g);
+    auto e_mid = framework::EigenTensor<T, 4>::From(*mid);
+
+    const int start = -(n - 1) / 2;
+    const int end = start + n;
+    for (int m = 0; m < N; m++) {
+      for (int i = 0; i < C; i++) {
+        auto i_x = e_x.slice(Eigen::array<int, 4>({{m, i, 0, 0}}),
+                             Eigen::array<int, 4>({{1, 1, H, W}}));
+
+        auto i_x_g = e_x_g.slice(Eigen::array<int, 4>({{m, i, 0, 0}}),
+                                 Eigen::array<int, 4>({{1, 1, H, W}}));
+
+        auto i_out_g = e_out_g.slice(Eigen::array<int, 4>({{m, i, 0, 0}}),
+                                     Eigen::array<int, 4>({{1, 1, H, W}}));
+
+        auto i_mid = e_mid.slice(Eigen::array<int, 4>({{m, i, 0, 0}}),
+                                 Eigen::array<int, 4>({{1, 1, H, W}}));
+
+        i_x_g.device(ctx.GetEigenDevice<Place>()) = i_mid.pow(-beta) * i_out_g;
+        for (int c = start; c <= end; c++) {
+          int ch = i + c;
+          if (ch < 0 || ch >= C) {
+            continue;
+          }
+
+          auto c_out = e_out.slice(Eigen::array<int, 4>({{m, ch, 0, 0}}),
+                                   Eigen::array<int, 4>({{1, 1, H, W}}));
+
+          auto c_mid = e_mid.slice(Eigen::array<int, 4>({{m, ch, 0, 0}}),
+                                   Eigen::array<int, 4>({{1, 1, H, W}}));
+
+          auto c_out_g = e_out_g.slice(Eigen::array<int, 4>({{m, ch, 0, 0}}),
+                                       Eigen::array<int, 4>({{1, 1, H, W}}));
+
+          i_x_g.device(ctx.GetEigenDevice<Place>()) +=
+              ratio * c_out_g * c_out * i_x / c_mid;
+        }
+      }
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/v2/framework/tests/test_lrn_op.py

+import unittest
+import numpy as np
+from op_test import OpTest
+
+
+class TestLRNOp(OpTest):
+    def get_input(self):
+        ''' TODO(gongweibao): why it's grad diff is so large?
+        x = np.ndarray(
+            shape=(self.N, self.C, self.H, self.W), dtype=float, order='C')
+        for m in range(0, self.N):
+            for i in range(0, self.C):
+                for h in range(0, self.H):
+                    for w in range(0, self.W):
+                        x[m][i][h][w] = m * self.C * self.H * self.W +  \
+                                        i * self.H * self.W +  \
+                                        h * self.W + w + 1
+        '''
+        x = np.random.rand(self.N, self.C, self.H, self.W).astype("float32")
+        return x + 1
+
+    def get_out(self):
+        start = -(self.n - 1) / 2
+        end = start + self.n
+
+        mid = np.empty((self.N, self.C, self.H, self.W), dtype=float)
+        mid.fill(self.k)
+        for m in range(0, self.N):
+            for i in range(0, self.C):
+                for c in range(start, end + 1):
+                    ch = i + c
+                    if ch < 0 or ch >= self.C:
+                        continue
+
+                    s = mid[m][i][:][:]
+                    r = self.x[m][ch][:][:]
+                    s += np.square(r) * self.alpha
+
+        mid2 = np.power(mid, -self.beta)
+        return np.multiply(self.x, mid2), mid
+
+    def get_attrs(self):
+        attrs = {
+            'n': self.n,
+            'k': self.k,
+            'alpha': self.alpha,
+            'beta': self.beta
+        }
+        return attrs
+
+    def setUp(self):
+        self.op_type = "lrn"
+        self.N = 2
+        self.C = 3
+        self.H = 5
+        self.W = 5
+
+        self.n = 5
+        self.k = 2.0
+        self.alpha = 0.0001
+        self.beta = 0.75
+        self.x = self.get_input()
+        self.out, self.mid_out = self.get_out()
+
+        self.inputs = {'X': self.x}
+        self.outputs = {'Out': self.out, 'MidOut': self.mid_out}
+        self.attrs = self.get_attrs()
+
+    def test_check_output(self):
+        self.check_output()
+
+    def test_check_grad_normal(self):
+        self.check_grad(['X'], 'Out', max_relative_error=0.01)
+
+
+if __name__ == "__main__":
+    unittest.main()