How to use Camera flash in the OpenCV4Android sample Tutorial-1 Camera Preview

Question

When I am using the following code the result is that flash is ON but it gives error that " it seems that your device does not support camera (or it is locked).Application will be closed". Please suggest me a method so that see the camera preview with flash ON.

private Camera mCamera;
void ledOn(){
    Camera.Parameters p = mCamera.getParameters();

    p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);

    mCamera.setParameters(p);
}

Answer 1

I had the same problem. I modified some code and it's work:

public class OpenCvCameraView extends JavaCameraView {

    public OpenCvCameraView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public List<String> getEffectList() {
        return mCamera.getParameters().getSupportedFlashModes();
    }

    public boolean isEffectSupported() {
        return (mCamera.getParameters().getFlashMode() != null);
    }

    public String getEffect() {
        return mCamera.getParameters().getFlashMode();
    }

    public void setEffect(String effect) {
        if(mCamera != null) {
            mCamera.getParameters();
            Camera.Parameters params = mCamera.getParameters();
            params.setFlashMode(effect);
            mCamera.setParameters(params);
        }
    }

    public void cameraRelease() {
        if(mCamera != null){
            mCamera.release();
        }
    }
}    

And put this methods into you main activity:

    public void turnOnTorch() {
        mOpenCVCameraView.setEffect(Camera.Parameters.FLASH_MODE_TORCH);

    }

    public void turnOffTorch() {
        mOpenCVCameraView.setEffect(Camera.Parameters.FLASH_MODE_ON);