python - TypeError:labels不是numpy数组，也不是标量

Question

刚从cv2开始，我想要的是在某个坐标窗口中为该对象提供种子，并让他连接可能在初始坐标框之外但与之接触的所有像素。
我从小型测试开始，以了解连接的componnet:

im=cv2.imread('test.png', 0)
ret, thresh = cv2.threshold(im, 254, 255, cv2.THRESH_BINARY)
output = cv2.connectedComponentsWithStats(thresh, 4, cv2.CV_32S)

然后

im=cv2.imread('test.png', 0)
ret, thresh = cv2.threshold(im, 254, 255, cv2.THRESH_BINARY)
thresh = cv2.bitwise_not(thresh)
output = cv2.connectedComponents(thresh, 4, cv2.CV_32S)

这两个outpute数组，到目前为止到目前为止还不错，然后我想查看引用docs https://docs.opencv.org/3.0-beta/modules/imgproc/doc/structural_analysis_and_shape_descriptors.html#connectedcomponents connectedComponentsWithStats(InputArray image, OutputArray labels, OutputArray stats, OutputArray centroids, int connectivity=8, int ltype=CV_32S)和 labels – destination labeled image的实际输出图像，因此我更改了上面共享的小代码中的最后一行:

output = cv2.connectedComponents(thresh,"out_test.png" ,4, cv2.CV_32S)

它给了我在问题中共享的错误。我还尝试了:

cv2.imwrite(dest_dir+"out_test.png", output)

并得到此错误:

TypeError: img is not a numerical tuple

我实际上如何可视化输出，因为我不想计算blob(对象)，它们的大小或其他任何东西，我只希望它们从我给的原始感兴趣区域中增长。

Answer 1

Help on built-in function connectedComponents:

connectedComponents(...)
    connectedComponents(image[, labels[, connectivity[, ltype]]]) -> retval, labels
    .   @overload
    .
    .   @param image the 8-bit single-channel image to be labeled
    .   @param labels destination labeled image
    .   @param connectivity 8 or 4 for 8-way or 4-way connectivity respectively
    .   @param ltype output image label type. Currently CV_32S and CV_16U are supported.

import cv2 
fname = "test.png"
img=cv2.imread(fname, 0)
ret, thresh = cv2.threshold(img, 254, 255, cv2.THRESH_BINARY)
thresh = cv2.bitwise_not(thresh)
nums, labels = cv2.connectedComponents(thresh, None, 4, cv2.CV_32S)
dst = cv2.convertScaleAbs(255.0*labels/nums)
cv2.imwrite("dst.png", dst)