code: private PointF transformCoordBitmapToTouch(float bx, float by) {
          matrix.getValues(m);
          float origW = getDrawable().getIntrinsicWidth();
          float origH = getDrawable().getIntrinsicHeight();
          float px = bx / origW;
          float py = by / origH;
          float finalX = m[Matrix.MTRANS_X] + getImageWidth() * px;
          float finalY = m[Matrix.MTRANS_Y] + getImageHeight() * py;
          return new PointF(finalX, finalY);
      }
docs: Inverse of transformCoordTouchToBitmap. This function will transform the coordinates in the
  drawable's coordinate system to the view's coordinate system.
  
  @param bx x-coordinate in original bitmap coordinate system
  @param by y-coordinate in original bitmap coordinate system
  @return Coordinates of the point in the view's coordinate system.