利用opencv库录制九宫格视频（C++实现）

在项目开始之前，我的环境已配置完成，具体环境如何配置可参考网络教程。下面我们开始项目的实现

库的导入

#include#include#includeusing namespace std;using namespace cv;

这就不多说了

开启摄像头

Mat frame;Mat newframe;string outputVideoPath = "F:\\C++language\\robocon.avi";VideoCapture capture(0);int frame_width = capture.get(CAP_PROP_FRAME_WIDTH);int frame_height = capture.get(CAP_PROP_FRAME_HEIGHT);VideoWriter writer;

开始摄像头，并获取摄像头的像素高度与宽度

定义所需变量

int num = 3;//原图片长宽皆被划分为三份，共划分成九份int stepwidth;//划分后单个图片的宽度int stepheight;//划分后的那个图片的高度int space = 5;//九宫格中每张图片的间隔

捕获图片并生成视频

capture >> frame;stepwidth = frame.cols / num;stepheight = frame.rows / num;resize(frame, frame, Size(stepwidth * num, stepheight * num), 1, 1, INTER_LINEAR);newframe = Mat(Size(frame.cols + (num - 1) * space, frame.rows + (num - 1) * space), CV_8UC3, Scalar(255, 255, 255));//新画布的生成writer.open(outputVideoPath, cv::VideoWriter::fourcc('M', 'J', 'P', 'G'), 10, Size(frame.cols + (num - 1) * space, frame.rows + (num - 1) * space));if (!capture.isOpened()){cout << "The camera cannot be opened" << endl;}if (!writer.isOpened()){cout << "The video cannot be saved" << endl;}

根据九宫格各张图片以及间隔的大小生成新的画布，用于存放新的九宫格图片

实现图片的抓取、转换与保存

int count = 1;while (count <= 60){capture >> frame;stepwidth = frame.cols / num;stepheight = frame.rows / num;resize(frame, frame, Size(stepwidth * num, stepheight * num), 1, 1, INTER_LINEAR);Mat newframe = Mat(Size(frame.cols + (num - 1) * space, frame.rows + (num - 1) * space), CV_8UC3, Scalar(255, 255, 255));int i = 0;int j = 0;for (i = 0; i < num; i++){for (j=0; j < num; j++){int x = stepwidth * j;int y = stepheight * i;frame(Rect(x, y, stepwidth, stepheight)).copyTo(newframe(Rect(x + space * j, y + space * i, stepwidth, stepheight)));}}imshow("output", newframe);waitKey(100);writer << newframe;count += 1;}}

视频以10帧的形式呈现，共60帧图片。