org.opencv.dnn

Class TextRecognitionModel

java.lang.Object

org.opencv.dnn.Model

org.opencv.dnn.TextRecognitionModel

public class TextRecognitionModel
extends Model

This class represents high-level API for text recognition networks. TextRecognitionModel allows to set params for preprocessing input image. TextRecognitionModel creates net from file with trained weights and config, sets preprocessing input, runs forward pass and return recognition result. For TextRecognitionModel, CRNN-CTC is supported.

Constructor Summary

Constructors

Constructor and Description
TextRecognitionModel(Net network) Create Text Recognition model from deep learning network Call setDecodeType() and setVocabulary() after constructor to initialize the decoding method
TextRecognitionModel(java.lang.String model) Create text recognition model from network represented in one of the supported formats Call setDecodeType() and setVocabulary() after constructor to initialize the decoding method
TextRecognitionModel(java.lang.String model, java.lang.String config) Create text recognition model from network represented in one of the supported formats Call setDecodeType() and setVocabulary() after constructor to initialize the decoding method

Method Summary

Modifier and Type	Method and Description
static TextRecognitionModel	__fromPtr__(long addr)
java.lang.String	getDecodeType() Get the decoding method
java.util.List<java.lang.String>	getVocabulary() Get the vocabulary for recognition.
java.lang.String	recognize(Mat frame) Given the input frame, create input blob, run net and return recognition result
void	recognize(Mat frame, java.util.List<Mat> roiRects, java.util.List<java.lang.String> results) Given the input frame, create input blob, run net and return recognition result
TextRecognitionModel	setDecodeOptsCTCPrefixBeamSearch(int beamSize) Set the decoding method options for "CTC-prefix-beam-search" decode usage
TextRecognitionModel	setDecodeOptsCTCPrefixBeamSearch(int beamSize, int vocPruneSize) Set the decoding method options for "CTC-prefix-beam-search" decode usage
TextRecognitionModel	setDecodeType(java.lang.String decodeType) Set the decoding method of translating the network output into string
TextRecognitionModel	setVocabulary(java.util.List<java.lang.String> vocabulary) Set the vocabulary for recognition.

Methods inherited from class org.opencv.dnn.Model

getNativeObjAddr, predict, setInputCrop, setInputMean, setInputParams, setInputParams, setInputParams, setInputParams, setInputParams, setInputParams, setInputScale, setInputSize, setInputSize, setInputSwapRB, setPreferableBackend, setPreferableTarget

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TextRecognitionModel

public TextRecognitionModel(Net network)

Create Text Recognition model from deep learning network Call setDecodeType() and setVocabulary() after constructor to initialize the decoding method

Parameters:

network - Net object

TextRecognitionModel

public TextRecognitionModel(java.lang.String model)

Create text recognition model from network represented in one of the supported formats Call setDecodeType() and setVocabulary() after constructor to initialize the decoding method

Parameters:

model - Binary file contains trained weights

TextRecognitionModel

public TextRecognitionModel(java.lang.String model,
                            java.lang.String config)

Create text recognition model from network represented in one of the supported formats Call setDecodeType() and setVocabulary() after constructor to initialize the decoding method

Parameters:

model - Binary file contains trained weights

config - Text file contains network configuration

Method Detail

__fromPtr__

public static TextRecognitionModel __fromPtr__(long addr)

getDecodeType

public java.lang.String getDecodeType()

Get the decoding method

Returns:

the decoding method

getVocabulary

public java.util.List<java.lang.String> getVocabulary()

Get the vocabulary for recognition.

Returns:

vocabulary the associated vocabulary

recognize

public java.lang.String recognize(Mat frame)

Given the input frame, create input blob, run net and return recognition result

Parameters:

frame - The input image

Returns:

The text recognition result

recognize

public void recognize(Mat frame,
                      java.util.List<Mat> roiRects,
                      java.util.List<java.lang.String> results)

Given the input frame, create input blob, run net and return recognition result

Parameters:

frame - The input image

roiRects - List of text detection regions of interest (cv::Rect, CV_32SC4). ROIs is be cropped as the network inputs

results - A set of text recognition results.

setDecodeOptsCTCPrefixBeamSearch

public TextRecognitionModel setDecodeOptsCTCPrefixBeamSearch(int beamSize)

Set the decoding method options for "CTC-prefix-beam-search" decode usage

Parameters:

beamSize - Beam size for search only take top vocPruneSize tokens in each search step, vocPruneSize <= 0 stands for disable this prune.

Returns:

automatically generated

setDecodeOptsCTCPrefixBeamSearch

public TextRecognitionModel setDecodeOptsCTCPrefixBeamSearch(int beamSize,
                                                             int vocPruneSize)

Set the decoding method options for "CTC-prefix-beam-search" decode usage

Parameters:

beamSize - Beam size for search

vocPruneSize - Parameter to optimize big vocabulary search, only take top vocPruneSize tokens in each search step, vocPruneSize <= 0 stands for disable this prune.

Returns:

automatically generated

setDecodeType

public TextRecognitionModel setDecodeType(java.lang.String decodeType)

Set the decoding method of translating the network output into string

Parameters:

decodeType - The decoding method of translating the network output into string, currently supported type: - "CTC-greedy" greedy decoding for the output of CTC-based methods - "CTC-prefix-beam-search" Prefix beam search decoding for the output of CTC-based methods

Returns:

automatically generated

setVocabulary

public TextRecognitionModel setVocabulary(java.util.List<java.lang.String> vocabulary)

Set the vocabulary for recognition.

Parameters:

vocabulary - the associated vocabulary of the network.

Returns:

automatically generated