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Diffstat (limited to 'tesseract/src/lstm/reversed.h')
-rw-r--r-- | tesseract/src/lstm/reversed.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/tesseract/src/lstm/reversed.h b/tesseract/src/lstm/reversed.h new file mode 100644 index 00000000..bcf18546 --- /dev/null +++ b/tesseract/src/lstm/reversed.h @@ -0,0 +1,91 @@ +/////////////////////////////////////////////////////////////////////// +// File: reversed.h +// Description: Runs a single network on time-reversed input, reversing output. +// Author: Ray Smith +// Created: Thu May 02 08:38:06 PST 2013 +// +// (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. +/////////////////////////////////////////////////////////////////////// + +#ifndef TESSERACT_LSTM_REVERSED_H_ +#define TESSERACT_LSTM_REVERSED_H_ + +#include "matrix.h" +#include "plumbing.h" + +namespace tesseract { + +// C++ Implementation of the Reversed class from lstm.py. +class Reversed : public Plumbing { + public: + TESS_API + explicit Reversed(const std::string& name, NetworkType type); + ~Reversed() override = default; + + // Returns the shape output from the network given an input shape (which may + // be partially unknown ie zero). + StaticShape OutputShape(const StaticShape& input_shape) const override; + + STRING spec() const override { + STRING spec(type_ == NT_XREVERSED ? "Rx" + : (type_ == NT_YREVERSED ? "Ry" : "Txy")); + // For most simple cases, we will output Rx<net> or Ry<net> where <net> is + // the network in stack_[0], but in the special case that <net> is an + // LSTM, we will just output the LSTM's spec modified to take the reversal + // into account. This is because when the user specified Lfy64, we actually + // generated TxyLfx64, and if the user specified Lrx64 we actually + // generated RxLfx64, and we want to display what the user asked for. + STRING net_spec = stack_[0]->spec(); + if (net_spec[0] == 'L') { + // Setup a from and to character according to the type of the reversal + // such that the LSTM spec gets modified to the spec that the user + // asked for + char from = 'f'; + char to = 'r'; + if (type_ == NT_XYTRANSPOSE) { + from = 'x'; + to = 'y'; + } + // Change the from char to the to char. + for (int i = 0; i < net_spec.length(); ++i) { + if (net_spec[i] == from) net_spec[i] = to; + } + return net_spec; + } + spec += net_spec; + return spec; + } + + // Takes ownership of the given network to make it the reversed one. + TESS_API + void SetNetwork(Network* network); + + // Runs forward propagation of activations on the input line. + // See Network for a detailed discussion of the arguments. + void Forward(bool debug, const NetworkIO& input, + const TransposedArray* input_transpose, + NetworkScratch* scratch, NetworkIO* output) override; + + // Runs backward propagation of errors on the deltas line. + // See Network for a detailed discussion of the arguments. + bool Backward(bool debug, const NetworkIO& fwd_deltas, + NetworkScratch* scratch, + NetworkIO* back_deltas) override; + + private: + // Copies src to *dest with the reversal according to type_. + void ReverseData(const NetworkIO& src, NetworkIO* dest) const; +}; + +} // namespace tesseract. + +#endif // TESSERACT_LSTM_REVERSED_H_ |