Read image data from rpi camera, compress image data and send.

image_send.cpp

#include <iostream>
#include <vector>
#include <string>
#include <sstream>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <time.h>

#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

#include <raspicam/raspicam_cv.h>

#define oops(msg) { perror(msg); exit(1); }

int main(int argc, char **argv)
{
    struct sockaddr_in saddr;
    struct hostent *hp;
    int portnum;
    int listenfd, connfd;

    if (argc < 3) {
        fprintf(stderr, "Usage: %s hostname portnum\n", argv[0]);
        exit(1);
    }
    hp = gethostbyname(argv[1]);
    if (hp == NULL) {
        fprintf(stderr, "No such host!\n");
        exit(1);
    }
    portnum = atoi(argv[2]);
    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    if (listenfd == -1) {
        oops("socket");
    }
    bzero((void *)&saddr, sizeof(saddr));
    bcopy((void *)hp->h_addr, (void *)&saddr.sin_addr, hp->h_length);
    saddr.sin_family = AF_INET;
    saddr.sin_port = htons(portnum);
    if (bind(listenfd, (struct sockaddr *)&saddr, sizeof(saddr)) != 0) {
        oops("bind");
    }
    if (listen(listenfd, 1) != 0) {
        oops("listen");
    }

    // 设置图像参数，打开摄像头
    raspicam::RaspiCam_Cv camera;
    camera.set(CV_CAP_PROP_FORMAT, CV_8UC3);
    camera.set(CV_CAP_PROP_FRAME_WIDTH, 640);
    camera.set(CV_CAP_PROP_FRAME_HEIGHT, 480);
    std::cout << "Openning camera..."; 
    if (!camera.open()) {
        std::cerr << "Error openning the camera!" << std::endl;
        return -1;
    }
    std::cout << "Successfully!" << endl;

    // 配置压缩参数
    std::vector<int> param = std::vector<int>(2);
    param[0] = CV_IMWRITE_JPEG_QUALITY;
    param[1] = 95;

    cv::Mat frame;            // 存储一帧图像
    std::vector<uchar> buff;  // 存储压缩后的数据
    char data_size_str[20];   // 字符串数组，压缩后数据的大小
    for (;;) {
        connfd = accept(listenfd, NULL, NULL);
        printf("Receive a request!\n");
        if (connfd == -1) {
            oops("accept");
        }

        for (;;) {
            camera.grab();
            camera.retrieve(frame);
            cv::imencode(".jpg", frame, buff, param);   // 压缩图像
            sprintf(data_size_str, "%d", buff.size());  // 将数据大小转换成字符
            send(connfd, data_size_str, 15, 0);         // 发送压缩数据的大小
            send(connfd, &buff[0], buff.size(), 0);     // 发送压缩数据
        }
        close(connfd);
    }
}