Loading an image using OpenCV in Android

Question

I apologize if this question has already been covered on this site, but I can't seem to find a straight forward answer. I'm making an android app that uses OpenCV to take a picture, process it to detect objects, and figure out the coordinates of those objects in the scene.

All the tutorials I find for android seem to be real time processing of the camera preview or using c++, which I would strongly prefer to not have to go down the c++ road. I'm sure I'm missing something simple but I don't know what it is.

On another note, the objects I'm trying to detect are billiards balls on a table. What would be the best pre-processing technique to better detect the balls? I did a quick test using the canny method, and it seems that the light reflecting off the balls breaks up the circle shape.

Answer 1

I know it's too late, but someone may use this.

Highgui has been removed from opencv for android.

You can use Imgcodes instead.

Mat BGRMat = Imgcodecs.imread(getResources().getDrawable(R.drawable.img).toString());

Answer 2

This works for me (got the answer from here: How to get Mat with a drawable input in Android using OpenCV)

Mat img = null;
try {
    img = Utils.loadResource(this, R.drawable.image_id, CvType.CV_8UC4);
} catch (IOException e) {
    e.printStackTrace();
}