python - 计算 OpenCV 中一条线上的白色像素数

Question

所以我正在尝试编写一个函数，我们称它为 foo，它采用二进制图像的路径，沿着它获取 Hough 线，然后返回按照 Hough 线上有多少白色像素排序的线。这是我到目前为止的代码，但它在“if(image[(x1+(istepx)),(y1+(istepy))].any()):”行崩溃索引无效。你们看到我可以做些什么来修复错误或知道 OpenCV 中内置的函数来做我想做的事吗？

def lineParams(line, length):
    (dist, angl) = line
    a = math.cos(angl)
    b = math.sin(angl)
    x0 = a * dist
    y0 = b * dist
    pt1 = (int(x0 - length * b), int(y0 + length * a))
    pt2 = (int(x0 + length * b), int(y0 - length * a))
    return (pt1, pt2)

def lineWhiteness(line, image):
    (pt1, pt2) = lineParams(line, len(image))
    count = 0
    (x1, y1) = pt1
    (x2, y2) = pt2
    stepx = (x2 - x1) / 100
    stepy = (y2 - y1) / 100
    for i in xrange(1, 100):
        #print image[(x1 + i * stepx), (y1 + i * stepy)]
        if(image[(x1 + (i * stepx)), (y1 + (i * stepy))].any()):
            count = count + 1
    return count

def foo(path, display):
    edges = CannyEdge(path, False)
    lines = cv2.HoughLines(edges, rho, theta, threshold)
    image = cv2.imread(path)
    lines = lines[0]
    lines = sorted(lines, key=lambda l: lineWhiteness(l, image))
    return lines

Answer 1

我最终通过使用 OpenCV 的线迭代器解决了这个问题，目前我正在尝试重写我的线参数函数以使其更好。

def lineWhiteness(line, image):
    (pt1, pt2) = lineParams(line, len(image))
    count = 0
    li = cv.InitLineIterator(cv.fromarray(image), pt1, pt2)
    for (r, g, b) in li:
        if (r or g or b):
            count += 1
    return count