ocr.hpp

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#ifndef __OPENCV_TEXT_OCR_HPP__
#define __OPENCV_TEXT_OCR_HPP__
 
#include <opencv2/core.hpp>
 
#include <vector>
#include <string>
 
namespace cv
{
namespace text
{
 
 
enum
{
    OCR_LEVEL_WORD,
    OCR_LEVEL_TEXTLINE
};
 
enum page_seg_mode
{
    PSM_OSD_ONLY,
    PSM_AUTO_OSD,
    PSM_AUTO_ONLY,
    PSM_AUTO,
    PSM_SINGLE_COLUMN,
    PSM_SINGLE_BLOCK_VERT_TEXT,
    PSM_SINGLE_BLOCK,
    PSM_SINGLE_LINE,
    PSM_SINGLE_WORD,
    PSM_CIRCLE_WORD,
    PSM_SINGLE_CHAR
};
 
enum ocr_engine_mode
{
    OEM_TESSERACT_ONLY,
    OEM_CUBE_ONLY,
    OEM_TESSERACT_CUBE_COMBINED,
    OEM_DEFAULT
};
 
//base class BaseOCR declares a common API that would be used in a typical text recognition scenario
class CV_EXPORTS_W BaseOCR
{
public:
    virtual ~BaseOCR() {};
    virtual void run(Mat& image, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) = 0;
    virtual void run(Mat& image, Mat& mask, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) = 0;
};
 
class CV_EXPORTS_W OCRTesseract : public BaseOCR
{
public:
    virtual void run(Mat& image, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) CV_OVERRIDE;
 
    virtual void run(Mat& image, Mat& mask, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) CV_OVERRIDE;
 
    // aliases for scripting
    CV_WRAP String run(InputArray image, int min_confidence, int component_level=0);
 
    CV_WRAP String run(InputArray image, InputArray mask, int min_confidence, int component_level=0);
 
    CV_WRAP virtual void setWhiteList(const String& char_whitelist) = 0;
 
 
    CV_WRAP static Ptr<OCRTesseract> create(const char* datapath=NULL, const char* language=NULL,
                                    const char* char_whitelist=NULL, int oem=OEM_DEFAULT, int psmode=PSM_AUTO);
};
 
 
/* OCR HMM Decoder */
 
enum decoder_mode
{
    OCR_DECODER_VITERBI = 0 // Other algorithms may be added
};
 
/* OCR classifier type*/
enum classifier_type
{
    OCR_KNN_CLASSIFIER = 0,
    OCR_CNN_CLASSIFIER = 1
};
 
class CV_EXPORTS_W OCRHMMDecoder : public BaseOCR
{
public:
 
    class CV_EXPORTS_W ClassifierCallback
    {
    public:
        virtual ~ClassifierCallback() { }
        virtual void eval( InputArray image, std::vector<int>& out_class, std::vector<double>& out_confidence);
    };
 
public:
    virtual void run(Mat& image, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) CV_OVERRIDE;
 
    virtual void run(Mat& image, Mat& mask, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) CV_OVERRIDE;
 
    // aliases for scripting
    CV_WRAP String run(InputArray image, int min_confidence, int component_level=0);
 
    CV_WRAP String run(InputArray image, InputArray mask, int min_confidence, int component_level=0);
 
    CV_WRAP static Ptr<OCRHMMDecoder> create(const Ptr<OCRHMMDecoder::ClassifierCallback> classifier,// The character classifier with built in feature extractor
                                     const String& vocabulary,                    // The language vocabulary (chars when ASCII English text)
                                                                                       //     size() must be equal to the number of classes
                                     InputArray transition_probabilities_table,        // Table with transition probabilities between character pairs
                                                                                       //     cols == rows == vocabulary.size()
                                     InputArray emission_probabilities_table,          // Table with observation emission probabilities
                                                                                       //     cols == rows == vocabulary.size()
                                     int mode = OCR_DECODER_VITERBI);         // HMM Decoding algorithm (only Viterbi for the moment)
 
    CV_WRAP static Ptr<OCRHMMDecoder> create(const String& filename,
 
                                     const String& vocabulary,                    // The language vocabulary (chars when ASCII English text)
                                                                                       //     size() must be equal to the number of classes
                                     InputArray transition_probabilities_table,        // Table with transition probabilities between character pairs
                                                                                       //     cols == rows == vocabulary.size()
                                     InputArray emission_probabilities_table,          // Table with observation emission probabilities
                                                                                       //     cols == rows == vocabulary.size()
                                     int mode = OCR_DECODER_VITERBI,                    // HMM Decoding algorithm (only Viterbi for the moment)
 
                                     int classifier = OCR_KNN_CLASSIFIER);              // The character classifier type
protected:
 
    Ptr<OCRHMMDecoder::ClassifierCallback> classifier;
    std::string vocabulary;
    Mat transition_p;
    Mat emission_p;
    decoder_mode mode;
};
 
CV_EXPORTS_W Ptr<OCRHMMDecoder::ClassifierCallback> loadOCRHMMClassifierNM(const String& filename);
 
CV_EXPORTS_W Ptr<OCRHMMDecoder::ClassifierCallback> loadOCRHMMClassifierCNN(const String& filename);
 
CV_EXPORTS_W Ptr<OCRHMMDecoder::ClassifierCallback> loadOCRHMMClassifier(const String& filename, int classifier);
 
CV_EXPORTS void createOCRHMMTransitionsTable(std::string& vocabulary, std::vector<std::string>& lexicon, OutputArray transition_probabilities_table);
 
CV_EXPORTS_W Mat createOCRHMMTransitionsTable(const String& vocabulary, std::vector<cv::String>& lexicon);
 
 
/* OCR BeamSearch Decoder */
 
class CV_EXPORTS_W OCRBeamSearchDecoder : public BaseOCR
{
public:
 
    class CV_EXPORTS_W ClassifierCallback
    {
    public:
        virtual ~ClassifierCallback() { }
        virtual void eval( InputArray image, std::vector< std::vector<double> >& recognition_probabilities, std::vector<int>& oversegmentation );
 
        int getWindowSize() {return 0;}
        int getStepSize() {return 0;}
    };
 
public:
    virtual void run(Mat& image, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) CV_OVERRIDE;
 
    virtual void run(Mat& image, Mat& mask, std::string& output_text, std::vector<Rect>* component_rects=NULL,
                     std::vector<std::string>* component_texts=NULL, std::vector<float>* component_confidences=NULL,
                     int component_level=0) CV_OVERRIDE;
 
    // aliases for scripting
    CV_WRAP String run(InputArray image, int min_confidence, int component_level=0);
 
    CV_WRAP String run(InputArray image, InputArray mask, int min_confidence, int component_level=0);
 
    static CV_WRAP
    Ptr<OCRBeamSearchDecoder> create(const Ptr<OCRBeamSearchDecoder::ClassifierCallback> classifier,// The character classifier with built in feature extractor
                                     const std::string& vocabulary,                    // The language vocabulary (chars when ASCII English text)
                                                                                       //     size() must be equal to the number of classes
                                     InputArray transition_probabilities_table,        // Table with transition probabilities between character pairs
                                                                                       //     cols == rows == vocabulary.size()
                                     InputArray emission_probabilities_table,          // Table with observation emission probabilities
                                                                                       //     cols == rows == vocabulary.size()
                                     text::decoder_mode mode = OCR_DECODER_VITERBI,    // HMM Decoding algorithm (only Viterbi for the moment)
                                     int beam_size = 500                               // Size of the beam in Beam Search algorithm
    );
 
    static //CV_WRAP FIXIT bug in handling of Java overloads
    Ptr<OCRBeamSearchDecoder> create(const String& filename,                           // The character classifier file
                                     const String& vocabulary,                         // The language vocabulary (chars when ASCII English text)
                                                                                       //     size() must be equal to the number of classes
                                     InputArray transition_probabilities_table,        // Table with transition probabilities between character pairs
                                                                                       //     cols == rows == vocabulary.size()
                                     InputArray emission_probabilities_table,          // Table with observation emission probabilities
                                                                                       //     cols == rows == vocabulary.size()
                                     text::decoder_mode mode = OCR_DECODER_VITERBI,    // HMM Decoding algorithm (only Viterbi for the moment)
                                     int beam_size = 500                               // Size of the beam in Beam Search algorithm
    );
protected:
 
    Ptr<OCRBeamSearchDecoder::ClassifierCallback> classifier;
    std::string vocabulary;
    Mat transition_p;
    Mat emission_p;
    decoder_mode mode;
    int beam_size;
};
 
CV_EXPORTS_W Ptr<OCRBeamSearchDecoder::ClassifierCallback> loadOCRBeamSearchClassifierCNN(const String& filename);
 
 
class CV_EXPORTS OCRHolisticWordRecognizer : public BaseOCR
{
public:
    virtual void run(Mat& image,
                     std::string& output_text,
                     std::vector<Rect>* component_rects = NULL,
                     std::vector<std::string>* component_texts = NULL,
                     std::vector<float>* component_confidences = NULL,
                     int component_level = OCR_LEVEL_WORD) CV_OVERRIDE = 0;
 
    virtual void run(Mat& image,
                     Mat& mask,
                     std::string& output_text,
                     std::vector<Rect>* component_rects = NULL,
                     std::vector<std::string>* component_texts = NULL,
                     std::vector<float>* component_confidences = NULL,
                     int component_level = OCR_LEVEL_WORD) CV_OVERRIDE = 0;
 
    static Ptr<OCRHolisticWordRecognizer> create(const std::string &archFilename,
                                                 const std::string &weightsFilename,
                                                 const std::string &wordsFilename);
};
 
 
}} // cv::text::
 
 
#endif // _OPENCV_TEXT_OCR_HPP_