OpenCV第四篇：边缘检测

比眉伴天荒 2024-04-08 11:28 45阅读 0赞

#### 1.图片边缘检测 ####

import cv2
    from numpy import ndarray
    
    if __name__ == '__main__':
        # 读取图像（图片地址，读取模式）
        img: ndarray = cv2.imread('1.jpg', cv2.IMREAD_COLOR)
    
        # 边缘检测
        # 参数：（输入图像，min梯度阈值，max梯度阈值，卷积核大小(default:3),梯度方程(default:False)）
        edges = cv2.Canny(img, 100, 200)
    
        # 保存图像
        cv2.imwrite('2.jpg', edges)

结果：![c079edd6a222468696634c36825879f0.png][]

#### 2.视频边缘检测 ####

import cv2
    from cv2 import VideoCapture
    
    if __name__ == '__main__':
        cap = cv2.VideoCapture('20.mp4')
    
        width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))  # 获取视频的宽度
        height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))  # 获取视频的高度
        fps = cap.get(cv2.CAP_PROP_FPS)  # 获取视频的帧率
        fourcc = int(cap.get(cv2.CAP_PROP_FOURCC))  # 视频的编码
    
        # 保存视频
        # 参数：（保存路径，编码器，帧率，画面尺寸，是否彩色）
        out = cv2.VideoWriter("output.mp4", fourcc, fps, (width, height), True)
    
        while cap.isOpened():
            # 读取视频帧
            ret, frame = cap.read()
            if ret:
                # 边缘检测
                # 参数：（输入图像，min梯度阈值，max梯度阈值，卷积核大小(default:3),梯度方程(default:False)）
                edges = cv2.Canny(frame, 100, 200)
                # 保存视频帧到视频容器
                out.write(edges)
    
                # 显示视频帧图片
                cv2.imshow('frame', edges)
                # 每帧的显示时间，并监听键盘事件
                key = cv2.waitKey(1)
                # 监听退出Q
                if key & 0xFF == ord('q'):
                    break
            else:
                break
    
        # Release everything if job is finished
        cap.release()
        out.release()
        cv2.destroyAllWindows()

结果：

![d3bdf5c4a55b4560a82f0532e4947136.gif][]![992aefd4657d4284a76b2217a00f2301.gif][]

[c079edd6a222468696634c36825879f0.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/08/aaf66fca08ae4665805dee6d5d7b8fc8.png
[d3bdf5c4a55b4560a82f0532e4947136.gif]: https://img-blog.csdnimg.cn/d3bdf5c4a55b4560a82f0532e4947136.gif
[992aefd4657d4284a76b2217a00f2301.gif]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/08/3a966b92a6cd4f0abfc2d2b71166b2df.gif