tesseract 4.1.1
Loading...
Searching...
No Matches
reversed.h
Go to the documentation of this file.
1
2// File: reversed.h
3// Description: Runs a single network on time-reversed input, reversing output.
4// Author: Ray Smith
5// Created: Thu May 02 08:38:06 PST 2013
6//
7// (C) Copyright 2013, Google Inc.
8// Licensed under the Apache License, Version 2.0 (the "License");
9// you may not use this file except in compliance with the License.
10// You may obtain a copy of the License at
11// http://www.apache.org/licenses/LICENSE-2.0
12// Unless required by applicable law or agreed to in writing, software
13// distributed under the License is distributed on an "AS IS" BASIS,
14// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15// See the License for the specific language governing permissions and
16// limitations under the License.
18
19#ifndef TESSERACT_LSTM_REVERSED_H_
20#define TESSERACT_LSTM_REVERSED_H_
21
22#include "matrix.h"
23#include "plumbing.h"
24
25namespace tesseract {
26
27// C++ Implementation of the Reversed class from lstm.py.
28class Reversed : public Plumbing {
29 public:
30 explicit Reversed(const STRING& name, NetworkType type);
31 ~Reversed() override = default;
32
33 // Returns the shape output from the network given an input shape (which may
34 // be partially unknown ie zero).
35 StaticShape OutputShape(const StaticShape& input_shape) const override;
36
37 STRING spec() const override {
39 : (type_ == NT_YREVERSED ? "Ry" : "Txy"));
40 // For most simple cases, we will output Rx<net> or Ry<net> where <net> is
41 // the network in stack_[0], but in the special case that <net> is an
42 // LSTM, we will just output the LSTM's spec modified to take the reversal
43 // into account. This is because when the user specified Lfy64, we actually
44 // generated TxyLfx64, and if the user specified Lrx64 we actually
45 // generated RxLfx64, and we want to display what the user asked for.
46 STRING net_spec = stack_[0]->spec();
47 if (net_spec[0] == 'L') {
48 // Setup a from and to character according to the type of the reversal
49 // such that the LSTM spec gets modified to the spec that the user
50 // asked for
51 char from = 'f';
52 char to = 'r';
53 if (type_ == NT_XYTRANSPOSE) {
54 from = 'x';
55 to = 'y';
56 }
57 // Change the from char to the to char.
58 for (int i = 0; i < net_spec.length(); ++i) {
59 if (net_spec[i] == from) net_spec[i] = to;
60 }
61 return net_spec;
62 }
63 spec += net_spec;
64 return spec;
65 }
66
67 // Takes ownership of the given network to make it the reversed one.
68 void SetNetwork(Network* network);
69
70 // Runs forward propagation of activations on the input line.
71 // See Network for a detailed discussion of the arguments.
72 void Forward(bool debug, const NetworkIO& input,
73 const TransposedArray* input_transpose,
74 NetworkScratch* scratch, NetworkIO* output) override;
75
76 // Runs backward propagation of errors on the deltas line.
77 // See Network for a detailed discussion of the arguments.
78 bool Backward(bool debug, const NetworkIO& fwd_deltas,
79 NetworkScratch* scratch,
80 NetworkIO* back_deltas) override;
81
82 private:
83 // Copies src to *dest with the reversal according to type_.
84 void ReverseData(const NetworkIO& src, NetworkIO* dest) const;
85};
86
87} // namespace tesseract.
88
89#endif // TESSERACT_LSTM_REVERSED_H_
NetworkType
Definition: network.h:43
@ NT_XREVERSED
Definition: network.h:56
@ NT_YREVERSED
Definition: network.h:57
@ NT_XYTRANSPOSE
Definition: network.h:58
Definition: strngs.h:45
int32_t length() const
Definition: strngs.cpp:189
NetworkType type_
Definition: network.h:293
const STRING & name() const
Definition: network.h:138
NetworkType type() const
Definition: network.h:112
PointerVector< Network > stack_
Definition: plumbing.h:136
void Forward(bool debug, const NetworkIO &input, const TransposedArray *input_transpose, NetworkScratch *scratch, NetworkIO *output) override
Definition: reversed.cpp:54
STRING spec() const override
Definition: reversed.h:37
~Reversed() override=default
void SetNetwork(Network *network)
Definition: reversed.cpp:47
StaticShape OutputShape(const StaticShape &input_shape) const override
Definition: reversed.cpp:33
bool Backward(bool debug, const NetworkIO &fwd_deltas, NetworkScratch *scratch, NetworkIO *back_deltas) override
Definition: reversed.cpp:66