def preview_image(img, order='rgb', over_disp=False):
    if (order == 'rgb'):
        cv2.imshow('preview', img[:, :, ::(- 1)])
    elif (order == 'bgr'):
        cv2.imshow('preview', img)
    elif (order == 'mono'):
        cv2.imshow('preview', img)
    else:
        raise ValueError('order parameter is invalid')
    if over_disp:
        cv2.resizeWindow('preview')
    cv2.waitKey(0)
    cv2.destroyAllWindows()
def preview_image(img, order='rgb', over_disp=False):
    if (order == 'rgb'):
        cv2.imshow('preview', img[:, :, ::(- 1)])
    elif (order == 'bgr'):
        cv2.imshow('preview', img)
    elif (order == 'mono'):
        cv2.imshow('preview', img)
    else:
        raise ValueError('order parameter is invalid')
    if over_disp:
        cv2.resizeWindow('preview')
    cv2.waitKey(0)
    cv2.destroyAllWindows()