ImageSource

Interface for producers of images. It can be implemented by developers to support other image sources, such as external cameras or image filesets.

How to Use:

Use BarcodeReader.setImageSource to set ImageSource as the source of image.
Add code in method getImage. When DBR finishes the current process and trying to start decoding from another image, it will call the getImage.
Trigger BarcodeReader.startScanning to start the barcode decoding thread when all above are configured.
When barcode decoding thread is started, users can stop the thread by calling BarcodeReader.stopScanning

interface com.dynamsoft.dbr.ImageSource

Method	Description
`getImage`	The method for users for complete. Get image/video from external sources and out put the data as `ImageData`.

getImage

The method for users for complete which returns ImageData. When using external sources, users can generate the external image source into ImageData and output them in method getImage so that the image can be recognized by the Barcode Reader.

The barcode reader will continuously use getImage to acquire ImageData for barcode decoding when:

Method BarcodeReader.setImageSource has been configured in user’s project.
BarcodeReader.startScanning is triggered.

ImageData getImage();

Return Value

An object of ImageData.

Code Snippet

Here we use CameraX as the example of the image source. The following code displays how to use CameraX to capture video frames and tranfer the video frames into ImageData.

private ImageData mImageData;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    try {
        mReader = new BarcodeReader();
    } catch (BarcodeReaderException e) {
        e.printStackTrace();
    }
    // Set image source
    mReader.setImageSource(new ImageSource() {
        @Override
        // Configure the getImage method.
        public ImageData getImageData() {
            return mImageData;
        }
    });
    // Configure the listener to receive the TextResult from the textResultCallback
    mReader.setTextResultListener(new TextResultListener() {
        @Override
        public void textResultCallback(int i, ImageData imageData, TextResult[] textResults) {
            // Add your code to execute when iTextResult is received.
        }
    }
}
// onResume start barcode decoding.
@Override
protected void onResume() {
    super.onResume();
    mReader.startScanning();
}
// onPause stop barcode decoding.
@Override
protected void onPause() {
    super.onPause();
    mReader.stopScanning();
}
// Get the buffer image from CameraX Analyzer and generate the image into ImageData.
private ImageAnalysis.Analyzer mBarcodeAnalyzer = new ImageAnalysis.Analyzer() {
    @Override
    public void analyze(@NonNull ImageProxy imageProxy) {
        try {
            if(isShowingDialog) {
                mImageData = null;
                return;
            }
            byte[] data = new byte[imageProxy.getPlanes()[0].getBuffer().remaining()];
            imageProxy.getPlanes()[0].getBuffer().get(data);
            int nRowStride = imageProxy.getPlanes()[0].getRowStride();
            int nPixelStride = imageProxy.getPlanes()[0].getPixelStride();
            ImageData imageData = new ImageData();
            imageData.bytes = data;
            imageData.width = imageProxy.getWidth();
            imageData.height = imageProxy.getHeight();
            imageData.stride = nRowStride;
            imageData.format =EnumImagePixelFormat.IPF_NV21;
            imageData.orientation = imageProxy.getImageInfo().getRotationDegrees();
            mImageData = imageData;
        } finally {
            imageProxy.close();
        }
    }
};