How to set camera resolution in OpenCV on Android?

edit

If you use Camera (Android) instead of VideoCapture, you can do it this way:

Camera.Parameters params = mCamera.getParameters();
List<Camera.Size> sizes = params.getSupportedPreviewSizes();

// position: variable where you choose between different supported resolutions, 
// this varies from phone to phone, even the order can be different, 
// ex. ascending or descending order.

mFrameWidth = (int) sizes.get(position).width;
mFrameHeight = (int) sizes.get(position).height;

params.setPreviewSize(mFrameWidth, mFrameHeight);
mCamera.setParameters(params); // mCamera is a Camera object

I initially wrote this answer thinking the question was about using Camera object. So for your case it should be something like this:

mFrameWidth = (int) sizes.get(position).width;
mFrameHeight = (int) sizes.get(position).height;

vc.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, mFrameWidth);
vc.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, mFrameHeight);

Be aware that getSupportedPreviewSizes() gives you video sizes and getSupportedPictureSizes() gives you camera/photograph sizes, which are different.