Python 说“TrackerMedianFlow_create()”不再是 cv2 的属性，库更新了吗？答案

【问题标题】：Python says that "TrackerMedianFlow_create()" is no longer an attribute of cv2, Has the Library been updated?Python 说“TrackerMedianFlow_create()”不再是 cv2 的属性，库更新了吗？
【发布时间】：2019-06-13 13:26:00
【问题描述】：

Python 表示 TrackerMedianFlow_create() 不再是 cv2 的属性。

我看过这里但不一样：OpenCV, How to pass parameters into cv2.TrackerMedianFlow_create function? 我已经在几个不和谐的服务器上询问过，但没有成功。我已经用 ctrl + c 直接从我的教科书中复制了这段代码，所以它应该是准确的。

import cv2
import numpy as np

cap = cv2.VideoCapture("../data/traffic.mp4")
_, frame = cap.read()

bbox = cv2.selectROI(frame, False, True)

cv2.destroyAllWindows()

tracker = cv2.TrackerMedianFlow_create()
status_tracker = tracker.init(frame, bbox)
fps = 0

while True:
    status_cap, frame = cap.read()
    if not status_cap:
        break

    if status_tracker:
        timer = cv2.getTickCount()
        status_tracker, bbox = tracker.update(frame)

    if status_tracker:
        x, y, w, h = [int(i) for i in bbox]
        cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 15)
        fps = cv2.getTickFrequency() / (cv2.getTickCount() - timer);
        cv2.putText(frame, "FPS: %.0f" % fps, (0, 80), cv2.FONT_HERSHEY_SIMPLEX, 3.5, (0, 0, 0), 8);
    else:
        cv2.putText(frame, "Tracking failure detected", (0, 80), cv2.FONT_HERSHEY_SIMPLEX, 3.5, (0,0,255), 8)

    cv2.imshow("MedianFlow tracker", frame)

    k = cv2.waitKey(1)

    if k == 27: 
        break

cv2.destroyAllWindows()

导致问题的我的行是：

tracker = cv2.TrackerMedianFlow_create()

直到代码运行为止。

Traceback (most recent call last):
  File "D:/Documents/E-Books/Comp Vision/opencv3computervisionwithpythoncookbook_ebook/OpenCV3ComputerVisionwithPythonCookbook_Code/Chapter04/myPart5.py", line 11, in <module>
    tracker = cv2.TrackerMedianFlow_create()
AttributeError: module 'cv2.cv2' has no attribute 'TrackerMedianFlow_create'

我希望它可以正常工作。

【问题讨论】：

标签： python opencv computer-vision cv2

【解决方案1】：

opencv 4.5.1 用户

opencv-contrib-python

import cv2
cv2.legacy_TrackerMedianFlow()

【讨论】：

【解决方案2】：

TrackerMedianFlow 是一个module within the opencv-contrib package，并且不是官方 OpenCV 发行版的标准配置。你需要安装 opencv-contrib 包才能访问TrackerMedianFlow_create()

根据documentation，您应该卸载没有附加模块的软件包，然后继续使用您需要的附加模块重新安装 opencv。

pip uninstall opencv-python
pip install opencv-contrib-python

【讨论】：

从 4.5.1 开始，它们被放入 legacy