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class LabelRecognizer

You are viewing a history document page of Dynamsoft Label Recognizer Android v2.2.20.

class com.dynamsoft.dlr.LabelRecognizer

Initialization Methods Summary

Method	Description
`LabelRecognizer`	Initialization of `LabelRecognizer` object.

Settings Methods Summary

Method	Description
`appendCharacterModelBuffer`	Appends CharacterModel to the SDK object.
`getRuntimeSettings`	Gets the current settings and saves it into a struct.
`updateRuntimeSettings`	Updates runtime settings with a given struct.
`resetRuntimeSettings`	Resets the runtime settings.
`initRuntimeSettings`	Initializes a new setting to the current label recognizer instance via template string.
`initRuntimeSettingsFromFile`	Initializes a new setting to the current label recognizer instance via template file.
`outputRuntimeSettings`	Clear all appended LabelRecognizerParameter settings in the SDK object.
`outputRuntimeSettingsToFile`	Outputs LabelRecognizerParameter settings into a file (JSON file).
`updateReferenceRegionFromBarcodeResults`	Updates reference region which is defined with source type LST_BARCODE.
`getModeArgument`	Get argument value for the specified mode parameter.
`setModeArgument`	Set argument value for the specified mode parameter.

Recognition Methods Summary

Method	Description
`recognizeBuffer`	Recognizes text from memory buffer containing image pixels in defined format.
`recognizeFile`	Recognizes text from a specified image file.
`recognizeImage`	Recognizes text from a bitmap.
`recognizeFileInMemory`	Recognizes text from an image file in memory.

Video Recognizing Methods Summary

Method	Description
`setImageSource`	Bind an instance of ImageSource to the Label Recognizer.
`startScanning`	Start the label recognizing thread in the video streaming scenario.
`stopScanning`	Stop the label recognizing thread in the video streaming scenario.
`setLabelResultListener`	Set callback interface to process recognized label results generated during frame processing.

General Methods Summary

Method	Description
`getVersion`	Returns the version number string for the SDK.

Initialization Methods Details

LabelRecognizer

Initialization of LabelRecognizer object.

LabelRecognizer() throws LabelRecognizerException

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

Settings Methods Details

appendCharacterModelBuffer

Appends CharacterModel into memory.

static void appendCharacterModelBuffer (String name, byte[] prototxtBuffer, byte[] txtBuffer, byte[] characterModelBuffer)

Parameters

[in] name A unique name for the appended CharacterModel.
[in] prototxtBuffer The .prototxt file data of the CharacterModel in a byte array.
[in] txtBuffer The .txt file data of the CharacterModel in a byte array.
[in] characterModelBuffer The .caffemodel file data of the CharacterModel in a byte array.

Code Snippet

AssetManager manager = getAssets();
InputStream isPrototxt = manager.open("CharacterModel/NumberLetter.prototxt");
byte[] prototxt = new byte[isPrototxt.available()];
isPrototxt.read(prototxt);
isPrototxt.close();
InputStream isCharacterModel = manager.open("CharacterModel/NumberLetter.caffemodel");
byte[] characterModel = new byte[isCharacterModel.available()];
isCharacterModel.read(characterModel);
isCharacterModel.close();
InputStream isTxt = manager.open("CharacterModel/NumberLetter.txt");
byte[] txt = new byte[isTxt.available()];
isTxt.read(txt);
isTxt.close();

LabelRecognizer.appendCharacterModelBuffer("NumberLetter", prototxt, txt, characterModel);

getRuntimeSettings

Get current runtime settings and save them into a DLRRuntimeSettings object.

DLRRuntimeSettings getRuntimeSettings () throws LabelRecognizerException

Return value

An object of DLRRuntimeSettings stores the current runtime settings.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
DLRRuntimeSettings settings = recognizer.getRuntimeSettings();

updateRuntimeSettings

Update runtime settings with a given DLRRuntimeSettings object.

void updateRuntimeSettings (DLRRuntimeSettings settings) throws LabelRecognizerException

Parameters

[in] settings The class object of template settings. See also DLRRuntimeSettings

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

DLRRuntimeSettings settings = recognizer.getRuntimeSettings();
settings.maxThreadCount = 1;
recognizer.updateRuntimeSettings(settings);

resetRuntimeSettings

Reset all runtime settings to default values.

void resetRuntimeSettings () throws LabelRecognizerException

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

DLRRuntimeSettings settings = recognizer.getRuntimeSettings();
settings.maxThreadCount = 4;
recognizer.updateRuntimeSettings(settings);
recognizer.resetRuntimeSettings();

initRuntimeSettings

Initializes a new setting to the current label recognizer instance via template file.

void initRuntimeSettings(String content) throws LabelRecognizerException

Parameters

[in] content A JSON string that represents the content of the settings.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
recognizer.initRuntimeSettings("{\"LabelRecognizerParameter\":{\"Name\":\"P1\", \"RegionPredetectionModes\":[{\"Mode\":\"RPM_GENERAL_HSV_CONTRAST\"}], \"ReferenceRegionNameArray\": [\"R1\"]},\"ReferenceRegion\":{\"Name\":\"R1\",\"Localization\":{\"SourceType\":\"LST_PREDETECTED_REGION\",\"RegionPredetectionModesIndex\":0},\"TextAreaNameArray\":[\"T1\"]},\"TextArea\":{\"Name\":\"T1\",\"CharacterModelName\":\"Number\"}}");

initRuntimeSettingsFromFile

Initializes a new setting to the current label recognizer instance via template file.

void initRuntimeSettingsFromFile(String filePath) throws LabelRecognizerException

Parameters

[in] filePath The settings file path.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
recognizer.initRuntimeSettingsFromFile("your file path");

outputRuntimeSettingsToFile

Outputs runtime settings and save them into a settings file (JSON file).

void outputRuntimeSettingsToFile (String filePath, String templateName) throws LabelRecognizerException

Parameters

[in] filePath The path of the output file which stores current settings.
[in] templateName A unique name for declaring current runtime settings.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

recognizer.initRuntimeSettings("{\"LabelRecognizerParameter\":{\"Name\":\"P1\", \"RegionPredetectionModes\":[{\"Mode\":\"RPM_GENERAL_HSV_CONTRAST\"}], \"ReferenceRegionNameArray\": [\"R1\"]},\"ReferenceRegion\":{\"Name\":\"R1\",\"Localization\":{\"SourceType\":\"LST_PREDETECTED_REGION\",\"RegionPredetectionModesIndex\":0},\"TextAreaNameArray\":[\"T1\"]},\"TextArea\":{\"Name\":\"T1\",\"CharacterModelName\":\"Number\"}}");
recognizer.outputRuntimeSettingsToFile("your saving file path", "P1");

outputRuntimeSettings

Outputs runtime settings and save them into a string.

String outputRuntimeSettings (String templateName) throws LabelRecognizerException

Parameters

[in] templateName A unique name for declaring current runtime settings.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

recognizer.initRuntimeSettings("{\"LabelRecognizerParameter\":{\"Name\":\"P1\", \"RegionPredetectionModes\":[{\"Mode\":\"RPM_GENERAL_HSV_CONTRAST\"}], \"ReferenceRegionNameArray\": [\"R1\"]},\"ReferenceRegion\":{\"Name\":\"R1\",\"Localization\":{\"SourceType\":\"LST_PREDETECTED_REGION\",\"RegionPredetectionModesIndex\":0},\"TextAreaNameArray\":[\"T1\"]},\"TextArea\":{\"Name\":\"T1\",\"CharacterModelName\":\"Number\"}}");
String settingsStr = recognizer.outputRuntimeSettings("P1");

getModeArgument

Get argument value for the specified mode parameter.

String getModeArgument(String modesName, int index, String argumentName) throws LabelRecognizerException 

Parameters

[in] modesName The mode parameter name to get argument.
[in] index The array index of mode parameter to indicate a specific mode.
[in] argumentName The name of the argument to get.

Return value

the optional argument for a specified mode in Modes parameters.

Exceptions

LabelRecognizerException

Remark

Check follow link for available modes and arguments:

RegionPredetectionModes

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

DLRRuntimeSettings settings = recognizer.getRuntimeSettings();
settings.furtherModes.regionPredetectionModes[0] = EnumRegionPredetectionMode.RPM_GENERAL_RGB_CONTRAST;
recognizer.updateRuntimeSettings(settings);
recognizer.setModeArgument("RegionPredetectionModes", 0, "AspectRatioRange", "100");
String argumentValue = recognizer.getModeArgument("RegionPredetectionModes", 0, "AspectRatioRange");

setModeArgument

Set argument value for the specified mode parameter.

void setModeArgument(String modesName, int index, String argumentName, String argumentValue) throws LabelRecognizerException 

Parameters

[in] modesName The mode parameter name to set argument.
[in] index The array index of mode parameter to indicate a specific mode.
[in] argumentName The name of the argument to set.
[in] argumentValue The value of the argument to set.

Exceptions

LabelRecognizerException

Remark

Check follow link for available modes and arguments:

RegionPredetectionModes

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

DLRRuntimeSettings settings = recognizer.getRuntimeSettings();
settings.furtherModes.regionPredetectionModes[0] = EnumRegionPredetectionMode.RPM_GENERAL_RGB_CONTRAST;
recognizer.updateRuntimeSettings(settings);
recognizer.setModeArgument("RegionPredetectionModes", 0, "AspectRatioRange", "100");

updateReferenceRegionFromBarcodeResults

Updates reference region which is defined with source type LST_BARCODE.

void updateReferenceRegionFromBarcodeResults (BarcodeResult[] barcodeResults, String templateName) throws LabelRecognizerException

Parameters

[in] barcodeResults The barcode results used to localize reference region. See also BarcodeResult.
[in] templateName The template name. A template name is the value of key LabelRecognizerParameter.Name defined in JSON formatted settings. If no template name is specified, current runtime settings will be used.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();

recognizer.initRuntimeSettings("{\"LabelRecognizerParameter\":{\"Name\":\"P1\", \"RegionPredetectionModes\":[{\"Mode\":\"RPM_GENERAL_HSV_CONTRAST\"}], \"ReferenceRegionNameArray\": [\"R1\"]},\"ReferenceRegion\":{\"Name\":\"R1\",\"Localization\":{\"SourceType\":\"LST_BARCODE\"},\"TextAreaNameArray\":[\"T1\"]},\"TextArea\":{\"Name\":\"T1\",\"CharacterModelName\":\"Number\"}}");
//Get barcodeResults from Dynamsoft Barcode Reader SDK
recognizer.updateReferenceRegionFromBarcodeResults(barcodeResults, "P1");

Recognition Methods Details

recognizeBuffer

Recognizes text from the memory buffer containing image pixels in defined format.

DLRResult[] recognizeBuffer(ImageData imageData) throws LabelRecognizerException

Parameters

[in] imageData An object of ImageData that represents an image.

Return value

All results recognized successfully.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
//Generate imageData from somewhere else
DLRResult[] result = recognizer.recognizeBuffer(imageData);

recognizeFile

Recognizes text from a specified image file.

DLRResult[] recognizeFile(String fileName) throws LabelRecognizerException 

Parameters

[in] fileName A string defining the file name.

Return value

All results recognized successfully.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
DLRResult[] result = recognizer.recognizeFile("full file path");

recognizeImage

Recognizes text from a bitmap.

DLRResult[] recognizeByImage (Bitmap image) throws LabelRecognizerException 

Parameters

[in] image A bitmap image.

Return value

All results recognized successfully.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
Bitmap img = BitmapFactory.decodeFile("full file path");
DLRResult[] result = recognizer.recognizeImage(img);

RecognizeFileInMemory

Recognizes text from a specified image file in memory.

DLRResult[] RecognizeFileInMemory(byte[] fileBytes) throws LabelRecognizerException

Parameters

[in] fileBytes The image file bytes in memory.

Return value

All results recognized successfully.

Exceptions

LabelRecognizerException

Code Snippet

LabelRecognizer recognizer = new LabelRecognizer();
// user code: read from an image into fileBytes 
byte[] fileBytes = null;
DLRResult[] result = recognizer.recognizeFileInMemory(fileBytes);

Video Recognizing Methods Details

setImageSource

Sets an instance of ImageSource to get images. CameraEnhancer is a specific implementation of ImageSource, which can help the Label Recognizer to acquire video frames continuously for recognition.

void setImageSource(ImageSource source)

Parameters

[in] source: An instance of ImageSource. If you are using Dynamsoft Camera Enhancer(DCE) to capture camera frames, pass an instance of CameraEnhancer.

Code Snippet

This code snippet displays a complete code on how to add CameraEnhancer to your project and start detecting and get detection results from the video streaming.

LabelRecognizer recognizer;
CameraEnhancer mCameraEnhancer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Be sure that you have added a cameraView in the layout file.
    DCECameraView cameraView = findViewById(R.id.cameraView);

    try {
        // Create an instance of Dynamsoft Label recognizer.
        recognizer = new  LabelRecognizer();
    } catch (LabelRecognizerException e) {
        e.printStackTrace();
    }
    mCameraEnhancer = new CameraEnhancer(MainActivity.this);
    mCameraEnhancer.setCameraView(cameraView);

    // Bind the Camera Enhancer instance to the Label recognizer instance.
    recognizer.setImageSource(mCameraEnhancer);

    // Result callback configurations
    LabelResultListener mLabelResultListener = new LabelResultListener() {
        // Obtain the recognized label results and display.
        @Override
        public void labelResultCallback(int id, ImageData imageData, DLRResult[] labelResults) {
            // Add your code to execute when label results are returned.
        }
    };

    recognizer.setLabelResultListener(mLabelResultListener);
}

@Override
public void onResume() {
    // Open the camera and start video label recognition 
    try {
        mCameraEnhancer.open();
    } catch (CameraEnhancerException e) {
        e.printStackTrace();
    }
    recognizer.startScanning();
    super.onResume();
}

@Override
public void onPause() {
    // Stop video label recognition 
    try {
        mCameraEnhancer.close();
    } catch (CameraEnhancerException e) {
        e.printStackTrace();
    }
    recognizer.stopScanning();
    super.onPause();
}

startScanning

Start the label recognition thread in the video streaming scenario. Please be sure that you have bound an object of ImageSource before you trigger startScanning.

void startScanning()

Code Snippet

You can view the complete code snippet in setImageSource.

stopScanning

Stop the label recognition thread in the video streaming scenario.

void stopScanning()

Code Snippet

You can view the complete code snippet in setImageSource.

setLabelResultListener

Set the callback interface to process recongnized label results generated during frame processing.

void setLabelResultListener(LabelResultListener labelResultListener)

Parameters

[in] labelResultListener: The Callback interface.

Code Snippet

You can view the complete code snippet in setImageSource.

General Methods Details

getVersion

Get version information of SDK.

static String getVersion()

Return value

The version information string.

Code Snippet

String versionInfo = LabelRecognizer.getVersion();