python-opecv createTrackbar

通过getTrackbarPos获取trackbar位置

    def threshold_trackbar(gray_res):
        cv.namedWindow('image',flags=cv.WINDOW_NORMAL)
        cv.createTrackbar('num','image',0,255,lambda x:None)
        while True:
            num = cv.getTrackbarPos('num','image')
            _, threshold1 = cv.threshold(gray_res,num,255,cv.THRESH_BINARY)
            cv.imshow('image',threshold1)

            k = cv.waitKey(1) & 0xFF
            if k == 27:
                break