def points_from_xywh(box):
    """
    Constructs a polygon representation from a rectangle described as a dict with keys x, y, w, h.
    """
    x, y, w, h = box['x'], box['y'], box['w'], box['h']
    # tesseract uses a different region representation format
    return "%i,%i %i,%i %i,%i %i,%i" % (
        x, y,
        x + w, y,
        x + w, y + h,
        x, y + h
    )