百度人脸识别HTTP SDk实战：基于C# ASP.NET CORE MVC 3.1
预计这是第一篇介绍在ASP.NET CORE 3.1平台下使用百度人脸识别在线sdk的文章，主要介绍人脸1：n检测/活体检验/人脸注册三大关键功能。
先看几个效果图吧
（1）人脸1：N检测，返回人脸对应用户信息
（2）活体检测：识别活体还好图片，防止人脸作弊
（3）人脸注册：检测用户是否存在
开始
在正式开始之前，需要一些准备以及预备知识，这里可以参考https://www.cnblogs.com/xiongze520/p/10387355.html以及https://www.cnblogs.com/xiongze520/p/10688545.html，讲的很详细。这里主要将后端的代码逻辑。
（1）人脸注册
在人脸注册前需要检测人脸库是否存在该人脸，已经存在了，则终止注册行为
代码如下：改方法接受前端返回的data64的图片字节串流，调用百度人脸识别接口方法进行判断，这里写了一个_faceEFService的数据库服务类，采用了EF core， var userModel = _faceEFService.GetByGuiIdAsync(userId).Result;返回数据库中userId对应的用户信息，其中userId是在注册人脸的时候，就保存到了百度云控制后台。
public IActionResult CheckIfUserHave(string imgData64FromAjax)
{
imgData64 = imgData64FromAjax;
string ApiKey = "ApiKey ";
string SecretKey = "SecretKey ";
var client = new Baidu.Aip.Face.Face(ApiKey, SecretKey);
client.Timeout = 10000;
var imageType = "BASE64"; //BASE64 URL
string requestImgData64 = imgData64FromAjax;
requestImgData64 = requestImgData64.Substring(imgData64.IndexOf(",") + 1);
string groupId = "FaceGroupForNetCore";
//string userId = new Guid().ToString();
var findUserJsonResult = client.Search(requestImgData64, imageType, groupId); //会出现222207（未找到用户）这个错误
if (findUserJsonResult["error_code"].ToString() == "0"
&& findUserJsonResult["error_msg"].ToString() == "SUCCESS")
{
var userList = JArray.Parse(findUserJsonResult["result"]["user_list"].ToString());
foreach (var user in userList)
{
var score = Convert.ToInt32(user["score"].ToString().Substring(0, 2));
if (score > 80)
{
Guid userId = Guid.Parse(user["user_id"].ToString());
var userModel = _faceEFService.GetByGuiIdAsync(userId).Result;
if (userModel != null)
{
var returnModel = new FaceReconitionModel
{
UserName = userModel.UserName
};
return Json(returnModel.UserName);
}
}
}
}
if (findUserJsonResult["error_code"].ToString() == "222202")
{
return Json("无法识别到人脸");
}
return View();
}（2）人脸注册：这块没啥了，大家应该都懂，就不介绍了。。。
[HttpPost]
public IActionResult FaceRegister(
[FromForm] FaceReconitionModel faceReconitionModel)
{
string ApiKey = "ApiKey ";
string SecretKey = "ApiKey ";
var client = new Baidu.Aip.Face.Face(ApiKey, SecretKey);
client.Timeout = 10000;
var imageType = "BASE64"; //BASE64 URL
imgData64 = imgData64.Substring(imgData64.IndexOf(",") + 1);
string groupId = "FaceGroupForNetCore";
string userId = Guid.NewGuid().ToString("N");
var userInfo = Guid.NewGuid();
var options = new Dictionary{
{"user_info", userInfo.ToString()},
{"quality_control", "NORMAL"},
{"liveness_control", "LOW"},
{"action_type", "REPLACE"}
};
var addUserFace = client.UserAdd(imgData64, imageType, groupId, userId, options);
var model = new FaceMdel
{
UserName = faceReconitionModel.UserName,
Month = faceReconitionModel.Month.ToString(),
Sex = faceReconitionModel.Sex,
Works = faceReconitionModel.Works,
Position = faceReconitionModel.Position,
GuidId = Guid.Parse(userId)
};
_faceEFService.AddAsync(model);
// _faceEFService.SaveChangeAsnc();
return RedirectToAction("index");
} （3）人脸活体检测以及人脸1：N检测
这里只要是人脸活体检测以及1：N检测，根据返回的UserId查找出数据库中对应的用户信息，依然很简单，大家应该看的懂。。
public IActionResult FaceDistinguish(string faceImgData64)
{
FaceImgData64 = faceImgData64;
string ApiKey = "ApiKey ";
string SecretKey = "ApiKey ";
var client = new Baidu.Aip.Face.Face(ApiKey, SecretKey);
client.Timeout = 10000;
// var imageType = "BASE64"; //BASE64 URL
faceImgData64 = faceImgData64.Substring(faceImgData64.IndexOf(",") + 1);
// string groupId = "FaceGroupForNetCore";
var faces = new JArray
{
new JObject
{
{"image", faceImgData64},
{"image_type", "BASE64"}
}
};
var checkLiving = client.Faceverify(faces);
//"error_code": 222202,
if (checkLiving["error_code"].ToString() == "0" && checkLiving["error_msg"].ToString() == "SUCCESS")
{
// var Living_result = Newtonsoft.Json.JsonConvert.DeserializeObject(LivingObj["result"].ToString()) as JObject;
var livingList = checkLiving["result"]["thresholds"];
double faceLiveness = Convert.ToDouble(checkLiving["result"]["face_liveness"].ToString());
//var frr = Newtonsoft.Json.JsonConvert.SerializeObject(Living_list.ToString());
//var frr_1eObj = Newtonsoft.Json.JsonConvert.DeserializeObject(Living_list.ToString()) as JObject;
double frr_1e4 = Convert.ToDouble(livingList["frr_1e-4"].ToString());
if (faceLiveness < frr_1e4)
{
return Json("不是活体");
}
}
if (checkLiving["error_code"].ToString() == "222202")
{
return Json("无法识别到人脸");
}
return Json("活体检验通过");
}