c++实现Face++ API的调用

1.Face++ API

Face++提供人脸相关技术的在线API服务给开发者使用，API 地址：http://www.faceplusplus.com.cn/。在使用Face++的在线API之前，肯定是要进行开发者注册申请的，申请完以后Face++会给开发者提供一个API
Key和Secret Key，在后期的服务器通信时会用到两个Key。

2.调用说明

以Face++人脸检测为例，输入参数分别是：

api_key（App的Face++ API Key）；

api_secret（APP的Face++ API Secret）；

img[POST]（待检测图片的URL 或者 通过POST方法上传的二进制数据，原始图片大小需要小于1M）；

返回数据为JSON格式的人脸的性别(gender), 年龄(age), 种族(race), 微笑程度(smiling), 眼镜(glass)和姿势(pose)等属性。调用之前需安装安装libcurl和jsoncpp下图为调用示例。



3.代码实现

#include<opencv2/opencv.hpp>
#include<iostream>
#include<vector>
#include<string>
#include <curl/curl.h>
#include "json.h"

using namespace std;
using namespace cv;

#define POSTURL  "http://apicn.faceplusplus.com/v2/detection/detect?api_key=06e4c8b1b3254eb2769d337457b8efac&api_secret=your=glass,pose,gender,age,race,smiling"

int writer(char *data, size_t size, size_t nmemb, string *writerData)
{
if (writerData == NULL)
return 0;
int len = size*nmemb;
writerData->append(data, len);
return len;
}

int main()
{
Mat img = imread("1.bmp");

vector<uchar> vec_Img;

vector<int> vecCompression_params;
vecCompression_params.push_back(CV_IMWRITE_JPEG_QUALITY);
vecCompression_params.push_back(90);
imencode(".jpg", img, vec_Img, vecCompression_params);

CURL *curl;
CURLcode res;

string buffer;

struct curl_slist *http_header = NULL;

curl = curl_easy_init();

curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writer);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &buffer);

struct curl_httppost *formpost = 0;
struct curl_httppost *lastptr = 0;
curl_formadd(&formpost, &lastptr, CURLFORM_PTRNAME, "img", CURLFORM_BUFFER, "imgdata", CURLFORM_BUFFERPTR, vec_Img.data(), CURLFORM_BUFFERLENGTH, vec_Img.size(), CURLFORM_END);
curl_easy_setopt(curl, CURLOPT_URL, POSTURL);
curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);

res = curl_easy_perform(curl);

curl_easy_cleanup(curl);

Json::Value root;
Json::Reader reader;
bool parsingSuccessful = reader.parse(buffer, root);

if (!parsingSuccessful)
{
cout << "Failed to parse the data!" << endl;
exit(0);
}

cout << buffer << endl;

waitKey(0);
return 0;
}

参考文献
【1】http://www.2cto.com/kf/201401/274988.html

【2】http://blog.csdn.net/u011000290/article/details/51189528