Scene Text Recognition

Classes
class	cv::text::BaseOCR
class	cv::text::OCRHMMDecoder
	OCRHMMDecoder class provides an interface for OCR using Hidden Markov Models. More...
class	cv::text::OCRTesseract
	OCRTesseract class provides an interface with the tesseract-ocr API (v3.02.02) in C++. More...

Enumerations
enum	{   cv::text::OCR_LEVEL_WORD,   cv::text::OCR_LEVEL_TEXTLINE }
enum	cv::text::decoder_mode { cv::text::OCR_DECODER_VITERBI = 0 }

Functions
Ptr < OCRHMMDecoder::ClassifierCallback >	cv::text::loadOCRHMMClassifierNM (const std::string &filename)
	Allow to implicitly load the default character classifier when creating an OCRHMMDecoder object. More...

Detailed Description

Enumeration Type Documentation

anonymous enum

Enumerator
OCR_LEVEL_WORD
OCR_LEVEL_TEXTLINE

enum cv::text::decoder_mode

Enumerator
OCR_DECODER_VITERBI

Function Documentation

Ptr<OCRHMMDecoder::ClassifierCallback> cv::text::loadOCRHMMClassifierNM

(

const std::string &

filename

)

Allow to implicitly load the default character classifier when creating an OCRHMMDecoder object.

Parameters

filename

The XML or YAML file with the classifier model (e.g. OCRHMM_knn_model_data.xml)

The default classifier is based in the scene text recognition method proposed by Lukás Neumann & Jiri Matas in [Neumann11b]. Basically, the region (contour) in the input image is normalized to a fixed size, while retaining the centroid and aspect ratio, in order to extract a feature vector based on gradient orientations along the chain-code of its perimeter. Then, the region is classified using a KNN model trained with synthetic data of rendered characters with different standard font types.