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Diffstat (limited to 'tesseract/src/classify/shapeclassifier.h')
| -rw-r--r-- | tesseract/src/classify/shapeclassifier.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/tesseract/src/classify/shapeclassifier.h b/tesseract/src/classify/shapeclassifier.h new file mode 100644 index 00000000..776880fc --- /dev/null +++ b/tesseract/src/classify/shapeclassifier.h @@ -0,0 +1,121 @@ +/////////////////////////////////////////////////////////////////////// +// 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_ |