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Diffstat (limited to 'tesseract/src/lstm/reversed.cpp')
-rw-r--r--tesseract/src/lstm/reversed.cpp88
1 files changed, 88 insertions, 0 deletions
diff --git a/tesseract/src/lstm/reversed.cpp b/tesseract/src/lstm/reversed.cpp
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+++ b/tesseract/src/lstm/reversed.cpp
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+///////////////////////////////////////////////////////////////////////
+// File: reversed.cpp
+// Description: Runs a single network on time-reversed input, reversing output.
+// Author: Ray Smith
+//
+// (C) Copyright 2013, Google Inc.
+// 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 "reversed.h"
+
+#include <cstdio>
+
+#include "networkscratch.h"
+
+namespace tesseract {
+
+Reversed::Reversed(const std::string& name, NetworkType type) : Plumbing(name) {
+ type_ = type;
+}
+
+// Returns the shape output from the network given an input shape (which may
+// be partially unknown ie zero).
+StaticShape Reversed::OutputShape(const StaticShape& input_shape) const {
+ if (type_ == NT_XYTRANSPOSE) {
+ StaticShape x_shape(input_shape);
+ x_shape.set_width(input_shape.height());
+ x_shape.set_height(input_shape.width());
+ x_shape = stack_[0]->OutputShape(x_shape);
+ x_shape.SetShape(x_shape.batch(), x_shape.width(), x_shape.height(),
+ x_shape.depth());
+ return x_shape;
+ }
+ return stack_[0]->OutputShape(input_shape);
+}
+
+// Takes ownership of the given network to make it the reversed one.
+void Reversed::SetNetwork(Network* network) {
+ stack_.clear();
+ AddToStack(network);
+}
+
+// Runs forward propagation of activations on the input line.
+// See NetworkCpp for a detailed discussion of the arguments.
+void Reversed::Forward(bool debug, const NetworkIO& input,
+ const TransposedArray* input_transpose,
+ NetworkScratch* scratch, NetworkIO* output) {
+ NetworkScratch::IO rev_input(input, scratch);
+ ReverseData(input, rev_input);
+ NetworkScratch::IO rev_output(input, scratch);
+ stack_[0]->Forward(debug, *rev_input, nullptr, scratch, rev_output);
+ ReverseData(*rev_output, output);
+}
+
+// Runs backward propagation of errors on the deltas line.
+// See NetworkCpp for a detailed discussion of the arguments.
+bool Reversed::Backward(bool debug, const NetworkIO& fwd_deltas,
+ NetworkScratch* scratch,
+ NetworkIO* back_deltas) {
+ NetworkScratch::IO rev_input(fwd_deltas, scratch);
+ ReverseData(fwd_deltas, rev_input);
+ NetworkScratch::IO rev_output(fwd_deltas, scratch);
+ if (stack_[0]->Backward(debug, *rev_input, scratch, rev_output)) {
+ ReverseData(*rev_output, back_deltas);
+ return true;
+ }
+ return false;
+}
+
+// Copies src to *dest with the reversal according to type_.
+void Reversed::ReverseData(const NetworkIO& src, NetworkIO* dest) const {
+ if (type_ == NT_XREVERSED)
+ dest->CopyWithXReversal(src);
+ else if (type_ == NT_YREVERSED)
+ dest->CopyWithYReversal(src);
+ else
+ dest->CopyWithXYTranspose(src);
+}
+
+} // namespace tesseract.