OpenCV  3.3.1-dev
Open Source Computer Vision
Classes | Enumerations | Functions

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::classifier_type {
  cv::text::OCR_KNN_CLASSIFIER = 0,
  cv::text::OCR_CNN_CLASSIFIER = 1
}
 
enum  cv::text::decoder_mode { cv::text::OCR_DECODER_VITERBI = 0 }
 
enum  cv::text::ocr_engine_mode {
  cv::text::OEM_TESSERACT_ONLY,
  cv::text::OEM_CUBE_ONLY,
  cv::text::OEM_TESSERACT_CUBE_COMBINED,
  cv::text::OEM_DEFAULT
}
 Tesseract.OcrEngineMode Enumeration. More...
 
enum  cv::text::page_seg_mode {
  cv::text::PSM_OSD_ONLY,
  cv::text::PSM_AUTO_OSD,
  cv::text::PSM_AUTO_ONLY,
  cv::text::PSM_AUTO,
  cv::text::PSM_SINGLE_COLUMN,
  cv::text::PSM_SINGLE_BLOCK_VERT_TEXT,
  cv::text::PSM_SINGLE_BLOCK,
  cv::text::PSM_SINGLE_LINE,
  cv::text::PSM_SINGLE_WORD,
  cv::text::PSM_CIRCLE_WORD,
  cv::text::PSM_SINGLE_CHAR
}
 Tesseract.PageSegMode Enumeration. More...
 

Functions

Ptr< OCRHMMDecoder::ClassifierCallbackcv::text::loadOCRHMMClassifier (const String &filename, int classifier)
 Allow to implicitly load the default character classifier when creating an OCRHMMDecoder object. More...
 
Ptr< OCRHMMDecoder::ClassifierCallbackcv::text::loadOCRHMMClassifierCNN (const String &filename)
 Allow to implicitly load the default character classifier when creating an OCRHMMDecoder object. More...
 
Ptr< OCRHMMDecoder::ClassifierCallbackcv::text::loadOCRHMMClassifierNM (const String &filename)
 Allow to implicitly load the default character classifier when creating an OCRHMMDecoder object. More...
 

Detailed Description

Enumeration Type Documentation

§ anonymous enum

anonymous enum
Enumerator
OCR_LEVEL_WORD 
Python: cv.text.OCR_LEVEL_WORD
OCR_LEVEL_TEXTLINE 
Python: cv.text.OCR_LEVEL_TEXTLINE

§ classifier_type

Enumerator
OCR_KNN_CLASSIFIER 
Python: cv.text.OCR_KNN_CLASSIFIER
OCR_CNN_CLASSIFIER 
Python: cv.text.OCR_CNN_CLASSIFIER

§ decoder_mode

Enumerator
OCR_DECODER_VITERBI 
Python: cv.text.OCR_DECODER_VITERBI

§ ocr_engine_mode

Tesseract.OcrEngineMode Enumeration.

Enumerator
OEM_TESSERACT_ONLY 
Python: cv.text.OEM_TESSERACT_ONLY
OEM_CUBE_ONLY 
Python: cv.text.OEM_CUBE_ONLY
OEM_TESSERACT_CUBE_COMBINED 
Python: cv.text.OEM_TESSERACT_CUBE_COMBINED
OEM_DEFAULT 
Python: cv.text.OEM_DEFAULT

§ page_seg_mode

Tesseract.PageSegMode Enumeration.

Enumerator
PSM_OSD_ONLY 
Python: cv.text.PSM_OSD_ONLY
PSM_AUTO_OSD 
Python: cv.text.PSM_AUTO_OSD
PSM_AUTO_ONLY 
Python: cv.text.PSM_AUTO_ONLY
PSM_AUTO 
Python: cv.text.PSM_AUTO
PSM_SINGLE_COLUMN 
Python: cv.text.PSM_SINGLE_COLUMN
PSM_SINGLE_BLOCK_VERT_TEXT 
Python: cv.text.PSM_SINGLE_BLOCK_VERT_TEXT
PSM_SINGLE_BLOCK 
Python: cv.text.PSM_SINGLE_BLOCK
PSM_SINGLE_LINE 
Python: cv.text.PSM_SINGLE_LINE
PSM_SINGLE_WORD 
Python: cv.text.PSM_SINGLE_WORD
PSM_CIRCLE_WORD 
Python: cv.text.PSM_CIRCLE_WORD
PSM_SINGLE_CHAR 
Python: cv.text.PSM_SINGLE_CHAR

Function Documentation

§ loadOCRHMMClassifier()

Ptr<OCRHMMDecoder::ClassifierCallback> cv::text::loadOCRHMMClassifier ( const String filename,
int  classifier 
)
Python:
retval=cv.text.loadOCRHMMClassifier(filename, classifier)

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

Parameters
filenameThe XML or YAML file with the classifier model (e.g. OCRBeamSearch_CNN_model_data.xml.gz)
classifierCan be one of classifier_type enum values.

§ loadOCRHMMClassifierCNN()

Ptr<OCRHMMDecoder::ClassifierCallback> cv::text::loadOCRHMMClassifierCNN ( const String filename)
Python:
retval=cv.text.loadOCRHMMClassifierCNN(filename)

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

Parameters
filenameThe XML or YAML file with the classifier model (e.g. OCRBeamSearch_CNN_model_data.xml.gz)

The CNN default classifier is based in the scene text recognition method proposed by Adam Coates & Andrew NG in [Coates11a]. The character classifier consists in a Single Layer Convolutional Neural Network and a linear classifier. It is applied to the input image in a sliding window fashion, providing a set of recognitions at each window location.

Deprecated:
use loadOCRHMMClassifier instead

§ loadOCRHMMClassifierNM()

Ptr<OCRHMMDecoder::ClassifierCallback> cv::text::loadOCRHMMClassifierNM ( const String filename)
Python:
retval=cv.text.loadOCRHMMClassifierNM(filename)

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

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

The KNN 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.

Deprecated:
loadOCRHMMClassifier instead