Apply a filter to the right or left.

Question

I want to implement filters on bitmap images, for example, on facebook, which apply filters to the image using gestures left or right. How to do it? I use this code to detect left and right gestures.

@Override
public boolean onTouchEvent(MotionEvent event) {
    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            x1 = event.getX();
            break;
        case MotionEvent.ACTION_UP:
            x2 = event.getX();
            float deltaX = x2 - x1;

            if (Math.abs(deltaX) > MIN_DISTANCE) {
                // Left to Right swipe action
                if (x2 > x1) {
                    Toast.makeText(this, "Left to Right swipe [Next]", Toast.LENGTH_SHORT).show();
                }

                // Right to left swipe action
                else {
                    Toast.makeText(this, "Right to Left swipe [Previous]", Toast.LENGTH_SHORT).show();
                }

            } else {
                // consider as something else - a screen tap for example
            }
            break;
    }
    return super.onTouchEvent(event);
}