☰

为什么我已经正确安装了，但仍出现 import cv2 错误？

tag-icon • tag-icon 16.04 python python3 opencv
为什么我已经正确安装了，但仍出现 import cv2 错误？

我正在尝试运行导入 opencv 的 python 脚本，我已经成功安装了 opencv，我可以看到安装和版本，但是当我尝试通过脚本调用它时，我收到导入错误

(cv) nikhil@nikhil-VirtualBox:~/object_detection_projects/opencv_traffic_counting$ python3
Python 3.5.2 (default, Nov 23 2017, 16:37:01) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
>>> 
[1]+  Stopped                 python3
(cv) nikhil@nikhil-VirtualBox:~/object_detection_projects/opencv_traffic_counting$ sudo python3 traffic.py
Traceback (most recent call last):
  File "traffic.py", line 8, in <module>
    import cv2
ImportError: No module named 'cv2'

我该如何解决这个问题？我使用的是 Ubuntu 16.04，我尝试运行的脚本是

import os
import logging
import logging.handlers
import random

import numpy as np
import skvideo.io
import cv2
import matplotlib.pyplot as plt

import utils
# without this some strange errors happen
cv2.ocl.setUseOpenCL(False)
random.seed(123)


from pipeline import (
    PipelineRunner,
    ContourDetection,
    Visualizer,
    CsvWriter,
    VehicleCounter)

# ============================================================================
IMAGE_DIR = "/Desktop"
VIDEO_SOURCE = "Car Detection in Traffic with Deep Learning Toolkit for LabVIEW.mp4"
SHAPE = (720, 1280)  # HxW
EXIT_PTS = np.array([
    [[732, 720], [732, 590], [1280, 500], [1280, 720]],
    [[0, 400], [645, 400], [645, 0], [0, 0]]
])
# ============================================================================


def train_bg_subtractor(inst, cap, num=500):
    '''
        BG substractor need process some amount of frames to start giving result
    '''
    print ('Training BG Subtractor...')
    i = 0
    for frame in cap:
        inst.apply(frame, None, 0.001)
        i += 1
        if i >= num:
            return cap


def main():
    log = logging.getLogger("main")

    # creating exit mask from points, where we will be counting our vehicles
    base = np.zeros(SHAPE + (3,), dtype='uint8')
    exit_mask = cv2.fillPoly(base, EXIT_PTS, (255, 255, 255))[:, :, 0]

    # there is also bgslibrary, that seems to give better BG substruction, but
    # not tested it yet
    bg_subtractor = cv2.createBackgroundSubtractorMOG2(
        history=500, detectShadows=True)

    # processing pipline for programming conviniance
    pipeline = PipelineRunner(pipeline=[
        ContourDetection(bg_subtractor=bg_subtractor,
                         save_image=True, image_dir=IMAGE_DIR),
        # we use y_weight == 2.0 because traffic are moving vertically on video
        # use x_weight == 2.0 for horizontal.
        VehicleCounter(exit_masks=[exit_mask], y_weight=2.0),
        Visualizer(image_dir=IMAGE_DIR),
        CsvWriter(path='./', name='report.csv')
    ], log_level=logging.DEBUG)

    # Set up image source
    # You can use also CV2, for some reason it not working for me
    cap = skvideo.io.vreader(VIDEO_SOURCE)

    # skipping 500 frames to train bg subtractor
    train_bg_subtractor(bg_subtractor, cap, num=500)

    _frame_number = -1
    frame_number = -1
    for frame in cap:
        if not frame.any():
            log.error("Frame capture failed, stopping...")
            break

        # real frame number
        _frame_number += 1

        # skip every 2nd frame to speed up processing
        if _frame_number % 2 != 0:
            continue

        # frame number that will be passed to pipline
        # this needed to make video from cutted frames
        frame_number += 1

        # plt.imshow(frame)
        # plt.show()
        # return

        pipeline.set_context({
            'frame': frame,
            'frame_number': frame_number,
        })
        pipeline.run()

# ============================================================================

if __name__ == "__main__":
    log = utils.init_logging()

    if not os.path.exists(IMAGE_DIR):
        log.debug("Creating image directory `%s`...", IMAGE_DIR)
        os.makedirs(IMAGE_DIR)

    main()

答案1

首先，您必须检查您的 lepi 上是否已安装 opencv。您可以使用以下命令来执行此操作。

python3 -c "import cv2; print(cv2.__version__)"

它会显示你的 opencv 版本。但如果没有，可能你的 opencv-python 尚未安装。然后尝试使用此命令进行安装。

sudo apt install python3-opencv

相关内容