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""" Python """
import cv2                  
img = cv2.imread(r"1.jpg")  """ 读取图片；r为取消 "" 作用 """ 
cv2.imshow("pic show", img) """ 展示图片 """
cv2.waitKey(0)              """ 阻塞进程，一直显示图片，直到用户关闭 """
print(type(img))            """ out:<class 'numpy.ndarray'>读取到的图片是numpy数据类型 """

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""" C++ """
#include <opencv2/opencv.hpp> 
int main() 
{ 
    """当前文件路径为cmake-build-release文件夹下,要将1.jpg图片移入其中"""
    cv::Mat img = cv::imread("1.jpg"); 
    cv::imshow("pic show", img); 
    cv::waitKey(0); 
}

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""" Python """
import numpy as np 
import cv2 
img = np.empty((200, 200, 3), np.uint8) """ 创建200 * 200 * 3 的空数组，数据类型为np.uint8（图片像素有0~255的整数表示）"""
img[..., 0] = 255                       """ 通过广播，将图片的第一通道赋值为255 """
img[..., 1] = 0                         """ 通过广播，将图片的第二通道赋值为0 """
img[..., 2] = 0 
cv2.imwrite("2.jpg", img)               """ cv2.imwrite([img_name], [data]) """

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""" C++ """ 

#include<opencv2/opencv.hpp> 
int main() 
{ 
    cv::Mat img = cv::Mat(200, 200, CV_8UC3, cv::Scalar(255, 0, 0)); 
    cv::imwrite("2.jpg", img); 
}

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""" Python """
import cv2 
cap = cv2.VideoCapture(0)         """ 读取摄像头 """
"""cap = cv2.VideoCapture("1.mp4")  # 读取视频文件 """
while True: 
    ret, frame = cap.read()       """ ret为Bool值，表示是否读取成功；frame为读取到的数据 """
    cv2.imshow('frame', frame) 
    if cv2.waitKey(1) & 0xFF == ord('q'): """ 捕捉用户输入，当用户按下"q"键时退出捕捉 """
        break 
cap.release()                     """ 释放摄像头等资源 """
cv2.destroyAllWindows()           """ 关闭所有窗口资源，防止自动释放窗口资源失败 """

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""" C++ """
#include <opencv2/opencv.hpp>

int main()
{
    cv::VideoCapture cap;
    cap = cv::VideoCapture("http://ivi.bupt.edu.cn/hls/cctv1.m3u8"); """ 读取网页中的视频 """
    while(true)
    {
        cv::Mat frame;
        cap >> frame;
        cv::imshow("frame", frame);
        if ( char(cv::waitKey(41)) == 'q') 
        {
            break;
        }
    }
    cap.release();
    cv::destroyAllWindows();
    return 1;
}

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""" Python """
import cv2 
src = cv2.imread(r"1.jpg") 
dst = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY) """ 将BGR图片转为Gray灰度图 """
cv2.imshow("src show", src) 
cv2.waitKey(0)

"""
  更多的转换内容可以在cv2.cvtColor(src, cv2.Other)的cv2.Other中找到
"""

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""" Python """
import cv2 
img = cv2.imread(r"1.jpg") 
img[..., 0] = 0 
img[..., 1] = 0 
cv2.imshow("dst show", img) 
cv2.waitKey(0)

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""" C++ """
#include <opencv2/opencv.hpp>
#include <vector>

int main(){
    cv::Mat img =  cv::Mat(200, 300, CV_8UC3, cv::Scalar(255, 0, 255)); //unsigned int8类型  BGR
    int i,j;

    for( i = 0; i < img.rows; i++){
        for( j = 0; j < img.cols; j++){
            img.at<cv::Vec3b>(i, j)[0] = 0;
            img.at<cv::Vec3b>(i, j)[1] = 0;
            img.at<cv::Vec3b>(i, j)[2] = 255;
        }
    }//速度慢

//    std::vector<cv::Mat> ms;
//    cv::split(img, ms);     //通道分割
//    ms[0] = 0;
//    ms[1] = 0;
//    ms[2] = 255;
//    cv::merge(ms, img);     //通道合并

    cv::imwrite("WritePic12.jpg", img);
    return 1;
}

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""" Python """

""" 提取图像中的字 """
import cv2
import numpy as np
number_6= cv2.imread("../Image/number_6.jpg")
number_6_hsv =cv2.cvtColor(number_6,cv2.COLOR_BGR2HSV)

cv2.imshow("src number_6", number_6)
cv2.imshow("hsv number_6", number_6_hsv)

""" 设定提取的高低阈值，中间值保留为255 """
low = np.array([0, 0, 150])
high = np.array([165, 100, 255])

""" 过滤函数：获取mask掩码，由0或255构成 """
mask = cv2.inRange(number_6_hsv, low, high)
cv2.imshow("mask number_6 ", mask)

""" 与操作 """
number_6_and = cv2.bitwise_and(number_6, number_6, mask=mask)
cv2.imshow("bitwise_and number_6 ", number_6_and)
cv2.waitKey(0)