C++实现Socket传输json封装的Mat

一般进行图片传输时，先用openCV把图片转换为Mat，然后封装到json当中，然后再从json中解析出来。这次是客户端向服务端传输。

Ps：客户端第一次发送一张图片，第二次发送两张图片，后面依次循环，转成Mat封装到json中，服务端接收并解析，如果是一张图片生成名称和相似度，如果是两张只生成相似度，封装到json，并返回至客户端（用于人脸识别的，读者可以根据自己的需要改动）

客户端：图片转换为Mat用imread即可，然后Mat通过imencode函数转为uchar*，再转换为string类型，然后通过c_str()函数转换为const char*，最后Base64编码存到json里面（我找的Base64.h编码只能用这个数据类型，所以这个转换数据类型卡了我很长时间，关键还是对数据类型不熟悉）

服务端：json里面的数据进行Base64解码成string，然后转换为uchar*，再通过imdecode转换成Mat，最后imshow显示或者imwrite保存（相当于客户端的逆过程）

openCV的配置过程在之前的博客中

json.hpp 下载地址https://github.com/nlohmann/json/tree/develop/include/nlohmann

一.服务端

main.cpp

[code]#include <iostream>
#include <stdio.h>
#include "Base64.h"
#include <winsock2.h>
#include "json1.hpp"
#include <opencv2/opencv.hpp>

#pragma comment(lib,"ws2_32.lib")
using namespace cv;
using json = nlohmann::json;

char revData[3888888];

int main(int argc, char* argv[])
{
//初始化WSA
WORD sockVersion = MAKEWORD(2, 2);
WSADATA wsaData;
if (WSAStartup(sockVersion, &wsaData) != 0)
{
return 0;
}

//创建套接字
SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (slisten == INVALID_SOCKET)
{
printf("socket error !");
return 0;
}

//绑定IP和端口
sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons(8888);
sin.sin_addr.S_un.S_addr = INADDR_ANY;

if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
{
printf("bind error !");
}

//开始监听
if (listen(slisten, 5) == SOCKET_ERROR)
{
printf("listen error !");
return 0;
}

//循环接收数据
SOCKET sClient;
sockaddr_in remoteAddr;
int nAddrlen = sizeof(remoteAddr);

//revData = (char*)malloc(sizeof(char) * 1000000);
int i = 1;
while (true)
{
printf("等待连接...\n");
sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
if (sClient == INVALID_SOCKET)
{
printf("accept error !");
continue;
}
printf("接受到一个连接：%s \r\n", inet_ntoa(remoteAddr.sin_addr));

int k = 1;
while (true)
{
//接收数据
int ret = recv(sClient, revData, 3888888, 0);
if (ret > 0)
{
revData[ret] = 0x00;
json o = json::parse(revData);
json j;

for (json::iterator it = o.begin(); it != o.end(); ++it)
{

if (it.key() == "mat1")
{
Mat img_decode;
std::string str_tmp = base64_decode(it.value());
std::vector<uchar> data(str_tmp.begin(), str_tmp.end());
img_decode = imdecode(data, CV_LOAD_IMAGE_COLOR);
imshow("pic", img_decode);
std::string num = std::to_string(k);
imwrite("D:\\" + num + ".jpg", img_decode);
k++;
waitKey(10);
}
else if (it.key() == "mat2")
{
if (it.value() == "")
{
j["name"] = "";
j["similarity"] = "";
}
else
{
Mat img_decode;
std::string str_tmp = base64_decode(it.value());
std::vector<uchar> data(str_tmp.begin(), str_tmp.end());
img_decode = imdecode(data, CV_LOAD_IMAGE_COLOR);
imshow("pic", img_decode);
std::string num = std::to_string(k);
imwrite("D:\\" + num + ".jpg", img_decode);
k++;
waitKey(10);
j["similarity"] = "";
}
}
}
//std::cout<< json::parse(revData)<< std::endl;
//printf(revData);
std::string s = j.dump();
const char * sendData;
sendData = s.c_str();
//const char * sendData = "你好，TCP客户端！\n";
send(sClient, sendData, strlen(sendData), 0);
}

//发送数据

}

}

closesocket(sClient);
closesocket(slisten);
WSACleanup();

return 0;
}

Base64.h

[code]#ifndef __BASE64_H__
#define __BASE64_H__

#include <iostream>
#include <string>

static const std::string base64_chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";

static inline bool is_base64(const char c)
{
return (isalnum(c) || (c == '+') || (c == '/'));
}

std::string base64_encode(const char * bytes_to_encode, unsigned int in_len)
{
std::string ret;
int i = 0;
int j = 0;
unsigned char char_array_3[3];
unsigned char char_array_4[4];

while (in_len--)
{
char_array_3[i++] = *(bytes_to_encode++);
if (i == 3)
{
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
for (i = 0; (i <4); i++)
{
ret += base64_chars[char_array_4[i]];
}
i = 0;
}
}
if (i)
{
for (j = i; j < 3; j++)
{
char_array_3[j] = '\0';
}

char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;

for (j = 0; (j < i + 1); j++)
{
ret += base64_chars[char_array_4[j]];
}

while ((i++ < 3))
{
ret += '=';
}

}
return ret;
}

std::string base64_decode(std::string const & encoded_string)
{
int in_len = (int)encoded_string.size();
int i = 0;
int j = 0;
int in_ = 0;
unsigned char char_array_4[4], char_array_3[3];
std::string ret;

while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
char_array_4[i++] = encoded_string[in_]; in_++;
if (i == 4) {
for (i = 0; i <4; i++)
char_array_4[i] = base64_chars.find(char_array_4[i]);

char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

for (i = 0; (i < 3); i++)
ret += char_array_3[i];
i = 0;
}
}
if (i) {
for (j = i; j <4; j++)
char_array_4[j] = 0;

for (j = 0; j <4; j++)
char_array_4[j] = base64_chars.find(char_array_4[j]);

char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
}

return ret;
}
#endif

二.客户端

main.cpp

[code]#include<WINSOCK2.H>
#include<STDIO.H>
#include<iostream>
#include<cstring>
#include <string>
#include <fstream>
#include "Bash64.h"
#include "json1.hpp"
#include <opencv2/opencv.hpp>

using namespace std;
using json = nlohmann::json;
using namespace cv;
#pragma comment(lib, "ws2_32.lib")

char chBuf1[3888888], chBuf2[3888888];

json readImg1()
{
json j;
Mat image = imread("E:\\testImage\\4.jpg");  //存放自己图像的路径
std::vector<unsigned char> data_encode;
int res = imencode(".jpg", image, data_encode);
std::string str_encode(data_encode.begin(), data_encode.end());
const char* c = str_encode.c_str();
j["mat2"] = "";
j["mat1"] = base64_encode(c, str_encode.size());

//cout << j << endl;

return j;
}

json readImg2()
{
json j;
Mat image;
const char* c;

image = imread("E:\\testImage\\5.jpg");  //存放自己图像的路径
std::vector<unsigned char> data_encode;
int res = imencode(".jpg", image, data_encode);
std::string str_encode1(data_encode.begin(), data_encode.end());
c = str_encode1.c_str();
j["mat1"] = base64_encode(c, str_encode1.size());

image = imread("E:\\testImage\\6.jpg");  //存放自己图像的路径
//std::vector<unsigned char> data_encode;
res = imencode(".jpg", image, data_encode);
std::string str_encode2(data_encode.begin(), data_encode.end());
c = str_encode2.c_str();
j["mat2"] = base64_encode(c, str_encode2.size());

return j;
}

int main()
{

WORD sockVersion = MAKEWORD(2, 2);
WSADATA data;
if (WSAStartup(sockVersion, &data) != 0)
{
return 0;
}

SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sclient == INVALID_SOCKET)
{
printf("invalid socket!");
return 0;
}

sockaddr_in serAddr;
serAddr.sin_family = AF_INET;
serAddr.sin_port = htons(8888);
serAddr.sin_addr.S_un.S_addr = inet_addr("192.168.3.72");
if (connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
{  //连接失败
printf("connect error !");
closesocket(sclient);
return 0;
}

json data1;
int i = 1;
while (true)
{
if (i > 10) break;
if (i % 2) data1 = readImg1();
else data1 = readImg2();
i++;

std::string s = data1.dump();
const char * sendData;
sendData = s.c_str();   //string转const char*
//char * sendData = "你好，TCP服务端，我是客户端\n";
send(sclient, sendData, strlen(sendData), 0);

//send()用来将数据由指定的socket传给对方主机
//int send(int s, const void * msg, int len, unsigned int flags)
//s为已建立好连接的socket，msg指向数据内容，len则为数据长度，参数flags一般设0
//成功则返回实际传送出去的字符数，失败返回-1，错误原因存于error

char recData[266680];
int ret = recv(sclient, recData, 266680, 0);
if (ret>0) {
recData[ret] = 0x00;
printf(recData);
printf("\n");
}
}

closesocket(sclient);

WSACleanup();
system("pause");
return 0;

}

Base64.h 上同