1 files changed, 74 insertions, 0 deletions
diff --git a/tensorflow/cc/gradients/image_grad.cc b/tensorflow/cc/gradients/image_grad.cc
new file mode 100644
index 0000000000..882709e1e2
--- /dev/null
+++ b/tensorflow/cc/gradients/image_grad.cc
@@ -0,0 +1,74 @@
+/* Copyright 2018 The TensorFlow 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.
+==============================================================================*/
+
+#include <vector>
+#include "tensorflow/cc/framework/grad_op_registry.h"
+#include "tensorflow/cc/framework/gradients.h"
+#include "tensorflow/cc/ops/image_ops_internal.h"
+#include "tensorflow/cc/ops/standard_ops.h"
+
+namespace tensorflow {
+namespace ops {
+namespace {
+
+Status ResizeNearestNeighborGradHelper(const Scope& scope, const Operation& op,
+                                       const std::vector<Output>& grad_inputs,
+                                       std::vector<Output>* grad_outputs) {
+  bool align_corners;
+  TF_RETURN_IF_ERROR(
+      GetNodeAttr(op.node()->attrs(), "align_corners", &align_corners));
+  // The internal gradient implementation needs the shape of the input image.
+  // x_shape = shape(x)[1:3]
+  //         = slice(shape(x), {1}, {3 - 1})
+  auto x_shape = Slice(scope, Shape(scope, op.input(0)), {1}, {2});
+  grad_outputs->push_back(internal::ResizeNearestNeighborGrad(
+      scope, grad_inputs[0], x_shape,
+      internal::ResizeNearestNeighborGrad::AlignCorners(align_corners)));
+  grad_outputs->push_back(NoGradient());
+  return scope.status();
+}
+REGISTER_GRADIENT_OP("ResizeNearestNeighbor", ResizeNearestNeighborGradHelper);
+
+Status ResizeBilinearGradHelper(const Scope& scope, const Operation& op,
+                                const std::vector<Output>& grad_inputs,
+                                std::vector<Output>* grad_outputs) {
+  bool align_corners;
+  TF_RETURN_IF_ERROR(
+      GetNodeAttr(op.node()->attrs(), "align_corners", &align_corners));
+  grad_outputs->push_back(internal::ResizeBilinearGrad(
+      scope, grad_inputs[0], op.input(0),
+      internal::ResizeBilinearGrad::AlignCorners(align_corners)));
+  grad_outputs->push_back(NoGradient());
+  return scope.status();
+}
+REGISTER_GRADIENT_OP("ResizeBilinear", ResizeBilinearGradHelper);
+
+Status ResizeBicubicGradHelper(const Scope& scope, const Operation& op,
+                               const std::vector<Output>& grad_inputs,
+                               std::vector<Output>* grad_outputs) {
+  bool align_corners;
+  TF_RETURN_IF_ERROR(
+      GetNodeAttr(op.node()->attrs(), "align_corners", &align_corners));
+  grad_outputs->push_back(internal::ResizeBicubicGrad(
+      scope, grad_inputs[0], op.input(0),
+      internal::ResizeBicubicGrad::AlignCorners(align_corners)));
+  grad_outputs->push_back(NoGradient());
+  return scope.status();
+}
+REGISTER_GRADIENT_OP("ResizeBicubic", ResizeBicubicGradHelper);
+
+}  // anonymous namespace
+}  // namespace ops
+}  // namespace tensorflow