Video Detecting Methods

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How to Implement Video Detecting

This code snippet displays a complete code on how to configure camera module, start detecting and get detection results from the video streaming.

DocumentNormalizer normalizer;
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 Document Normalizer.
        normalizer = new DocumentNormalizer();
    } catch (DocumentNormalizerException e) {
        e.printStackTrace();
    }
    mCameraEnhancer = new CameraEnhancer(MainActivity.this);
    mCameraEnhancer.setCameraView(cameraView);

    // Bind the Camera Enhancer instance to the Document Normalizer instance.
    normalizer.setImageSource(mCameraEnhancer);

    // Result callback configurations
    DetectResultListener mDetectResultListener = new DetectResultListener() {
        // Obtain the detected quad detection results and display.
        @Override
        public void detectResultCallback(int id, ImageData imageData, DetectedQuadResult[] detectedResults) {
            // Add your code to execute when quad detection results are returned.
        }
    };

    normalizer.setDetectResultListener(mDetectResultListener);
}

@Override
public void onResume() {
    // Open the camera and start video quad detecting 
    try {
        mCameraEnhancer.open();
    } catch (CameraEnhancerException e) {
        e.printStackTrace();
    }
    normalizer.startDetecting();
    super.onResume();
}

@Override
public void onPause() {
    // Stop video quad detecting 
    try {
        mCameraEnhancer.close();
    } catch (CameraEnhancerException e) {
        e.printStackTrace();
    }
    normalizer.stopDetecting();
    super.onPause();
}

Note:

DynamsoftCameraEnhancer library is included when implementing Video Quad Detecting. It provides APIs that help you quickly deploy a camera module and capture video streaming for document normalizer.

Methods

Use the following methods to control the start/stop of video streaming document detecting and get the detection results.

Method	Description
`setImageSource`	Sets an instance of ImageSource to get images.
`startDetecting`	Start the document quad detection thread in the video streaming scenario.
`stopDetecting`	Stop the document quad detection thread in the video streaming scenario.
`setDetectResultListener`	Set callback interface to process detection results generated during frame detecting.

setImageSource

Sets an instance of ImageSource to get images. CameraEnhancer is a specific implementation of ImageSource, which can help the Document Normalizer 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

// Create an instance of DynamsoftCameraEnhancer and set it as the image source.
DCECameraView cameraView = findViewById(R.id.cameraView);
CameraEnhancer mCameraEnhancer; = new CameraEnhancer(MainActivity.this);
mCameraEnhancer.setCameraView(cameraView);
normalizer.setImageSource(mCameraEnhancer);

startDetecting

Start the document quad detection thread in the video streaming scenario. Please be sure that you have bound a Camera Enhancer to the document normalizer before you trigger startDetecting.

void startDetecting()

Code Snippet

normalizer.startDetecting();

stopDetecting

Stop the document quad detection thread in the video streaming scenario.

void stopDetecting()

Code Snippet

normalizer.startDetecting();

setDetectResultListener

Set the callback interface to process detection results generated during frame detecting.

void setDetectResultListener(DetectResultListener detectResultListener)

Parameters

[in] detectResultListener: The Callback interface.

Code Snippet

// Result callback configurations
DetectResultListener mDetectResultListener = new DetectResultListener() {
    // Obtain the detected quad detection results and display.
    @Override
    public void detectResultCallback(int id, ImageData imageData, DetectedQuadResult[] detectedResults) {
        // Add your code to execute when quad detection results are returned.
    }
};
normalizer.setDetectResultListener(mDetectResultListener);