OpenCV  3.0.0
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cv::text::OCRHMMDecoder Class Reference

OCRHMMDecoder class provides an interface for OCR using Hidden Markov Models. More...

#include "ocr.hpp"

Inheritance diagram for cv::text::OCRHMMDecoder:
cv::text::BaseOCR

Classes

class  ClassifierCallback
 Callback with the character classifier is made a class. More...
 

Public Member Functions

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)
 Recognize text using HMM. More...
 
- Public Member Functions inherited from cv::text::BaseOCR
virtual ~BaseOCR ()
 

Static Public Member Functions

static Ptr< OCRHMMDecodercreate (const Ptr< OCRHMMDecoder::ClassifierCallback > classifier, const std::string &vocabulary, InputArray transition_probabilities_table, InputArray emission_probabilities_table, decoder_mode mode=OCR_DECODER_VITERBI)
 Creates an instance of the OCRHMMDecoder class. Initializes HMMDecoder. More...
 

Protected Attributes

Ptr
< OCRHMMDecoder::ClassifierCallback
classifier
 
Mat emission_p
 
decoder_mode mode
 
Mat transition_p
 
std::string vocabulary
 

Detailed Description

OCRHMMDecoder class provides an interface for OCR using Hidden Markov Models.

Note

Member Function Documentation

static Ptr<OCRHMMDecoder> cv::text::OCRHMMDecoder::create ( const Ptr< OCRHMMDecoder::ClassifierCallback classifier,
const std::string &  vocabulary,
InputArray  transition_probabilities_table,
InputArray  emission_probabilities_table,
decoder_mode  mode = OCR_DECODER_VITERBI 
)
static

Creates an instance of the OCRHMMDecoder class. Initializes HMMDecoder.

Parameters
classifierThe character classifier with built in feature extractor.
vocabularyThe language vocabulary (chars when ascii english text). vocabulary.size() must be equal to the number of classes of the classifier.
transition_probabilities_tableTable with transition probabilities between character pairs. cols == rows == vocabulary.size().
emission_probabilities_tableTable with observation emission probabilities. cols == rows == vocabulary.size().
modeHMM Decoding algorithm. Only OCR_DECODER_VITERBI is available for the moment (http://en.wikipedia.org/wiki/Viterbi_algorithm).
virtual void cv::text::OCRHMMDecoder::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 
)
virtual

Recognize text using HMM.

Takes image on input and returns recognized text in the output_text parameter. Optionally provides also the Rects for individual text elements found (e.g. words), and the list of those text elements with their confidence values.

Parameters
imageInput image CV_8UC1 with a single text line (or word).
output_textOutput text. Most likely character sequence found by the HMM decoder.
component_rectsIf provided the method will output a list of Rects for the individual text elements found (e.g. words).
component_textsIf provided the method will output a list of text strings for the recognition of individual text elements found (e.g. words).
component_confidencesIf provided the method will output a list of confidence values for the recognition of individual text elements found (e.g. words).
component_levelOnly OCR_LEVEL_WORD is supported.

Implements cv::text::BaseOCR.

Member Data Documentation

Ptr<OCRHMMDecoder::ClassifierCallback> cv::text::OCRHMMDecoder::classifier
protected
Mat cv::text::OCRHMMDecoder::emission_p
protected
decoder_mode cv::text::OCRHMMDecoder::mode
protected
Mat cv::text::OCRHMMDecoder::transition_p
protected
std::string cv::text::OCRHMMDecoder::vocabulary
protected

The documentation for this class was generated from the following file: