1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
///////////////////////////////////////////////////////////////////////
// File: shapeclassifier.h
// Description: Base interface class for classifiers that return a
// shape index.
// Author: Ray Smith
//
// (C) Copyright 2011, 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_CLASSIFY_SHAPECLASSIFIER_H_
#define TESSERACT_CLASSIFY_SHAPECLASSIFIER_H_
#include <tesseract/unichar.h>
struct Pix;
namespace tesseract {
class ScrollView;
class UNICHARSET;
template <typename T> class PointerVector;
struct ShapeRating;
class ShapeTable;
class TrainingSample;
class TrainingSampleSet;
struct UnicharRating;
// Interface base class for classifiers that produce ShapeRating results.
class TESS_API ShapeClassifier {
public:
virtual ~ShapeClassifier() = default;
// Classifies the given [training] sample, writing to results.
// If page_pix is not nullptr, the overriding function may call
// sample.GetSamplePix(padding, page_pix) to get an image of the sample
// padded (with real image data) by the given padding to extract features
// from the image of the character. Other members of TrainingSample:
// features(), micro_features(), cn_feature(), geo_feature() may be used
// to get the appropriate tesseract features.
// If debug is non-zero, then various degrees of classifier dependent debug
// information is provided.
// If keep_this (a UNICHAR_ID) is >= 0, then the results should always
// contain keep_this, and (if possible) anything of intermediate confidence.
// (Used for answering "Why didn't it get that right?" questions.) It must
// be a UNICHAR_ID as the callers have no clue how to choose the best shape
// that may contain a desired answer.
// The return value is the number of classes saved in results.
// NOTE that overriding functions MUST clear and sort the results by
// descending rating unless the classifier is working with a team of such
// classifiers.
// NOTE: Neither overload of ClassifySample is pure, but at least one must
// be overridden by a classifier in order for it to do anything.
virtual int UnicharClassifySample(const TrainingSample& sample, Pix* page_pix,
int debug, UNICHAR_ID keep_this,
std::vector<UnicharRating>* results);
protected:
virtual int ClassifySample(const TrainingSample& sample, Pix* page_pix,
int debug, UNICHAR_ID keep_this,
std::vector<ShapeRating>* results);
public:
// Returns the shape that contains unichar_id that has the best result.
// If result is not nullptr, it is set with the shape_id and rating.
// Returns -1 if ClassifySample fails to provide any result containing
// unichar_id. BestShapeForUnichar does not need to be overridden if
// ClassifySample respects the keep_this rule.
virtual int BestShapeForUnichar(const TrainingSample& sample, Pix* page_pix,
UNICHAR_ID unichar_id, ShapeRating* result);
// Provides access to the ShapeTable that this classifier works with.
virtual const ShapeTable* GetShapeTable() const = 0;
// Provides access to the UNICHARSET that this classifier works with.
// Must be overridden IFF GetShapeTable() returns nullptr.
virtual const UNICHARSET& GetUnicharset() const;
// Visual debugger classifies the given sample, displays the results and
// solicits user input to display other classifications. Returns when
// the user has finished with debugging the sample.
// Probably doesn't need to be overridden if the subclass provides
// DisplayClassifyAs.
void DebugDisplay(const TrainingSample& sample, Pix* page_pix,
UNICHAR_ID unichar_id);
// Displays classification as the given unichar_id. Creates as many windows
// as it feels fit, using index as a guide for placement. Adds any created
// windows to the windows output and returns a new index that may be used
// by any subsequent classifiers. Caller waits for the user to view and
// then destroys the windows by clearing the vector.
virtual int DisplayClassifyAs(const TrainingSample& sample, Pix* page_pix,
UNICHAR_ID unichar_id, int index,
PointerVector<ScrollView>* windows);
// Prints debug information on the results. context is some introductory/title
// message.
virtual void UnicharPrintResults(
const char* context, const std::vector<UnicharRating>& results) const;
virtual void PrintResults(const char* context,
const std::vector<ShapeRating>& results) const;
protected:
// Removes any result that has all its unichars covered by a better choice,
// regardless of font.
void FilterDuplicateUnichars(std::vector<ShapeRating>* results) const;
};
} // namespace tesseract.
#endif // TESSERACT_CLASSIFY_SHAPECLASSIFIER_H_
|
GitWeb