引言：
随着AI人工智能的发展，物联网技术逐渐进入平常百姓家，而人脸融合技术更能体现AI人工智能的发展，人脸融合技术算是比较“老”的技术，在众多的如美图秀秀等修图软件面前此技术很是渺茫，本博客为什么要写关于人脸融合呢？因为在项目中用到了😅,也是学习新技术，用此博客来记录，方便后期再次使用。

一、人脸融合原理

给定一个模板图，根据“人脸位置检测”接口获取到脸部准确位置( “top”, “left”,“width”,“height”)，将要融合的图通过发送请求给第三方接口，反馈一个json格式的字符串，从字符串中提取出“result”对应的字符串，即融合成的图片base64格式的字符串，再将base64格式字符串图片格式转成图片。

二、代码实现

1.注册账号

在Face++网站注册个人Key和Secert
Web API：https://console.faceplusplus.com.cn/documents/5671787

2.创建发送请求和反馈的类

using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Net; using System.Net.Security; using System.Security.Cryptography.X509Certificates; using System.Text; using System.Threading; using System.Web; namespace Coommon { public static class HttpHelper4MultipartForm { public class FileParameter { public byte[] File             { get; set; } public string FileName             { get; set; } public string ContentType             { get; set; } public FileParameter(byte[] file) : this(file, null) { } public FileParameter(byte[] file, string filename) : this(file, filename, null) { } public FileParameter(byte[] file, string filename, string contenttype) { this.File = file; this.FileName = filename; this.ContentType = contenttype; } } private static readonly Encoding encoding = Encoding.UTF8; /// <summary> /// MultipartForm请求 /// </summary> /// <param name="postUrl">服务地址</param> /// <param name="userAgent"></param> /// <param name="postParameters">参数</param> /// <returns></returns> public static HttpWebResponse MultipartFormDataPost(string postUrl, string userAgent, Dictionary<string, object> postParameters) { string text = string.Format("----------{0:N}", Guid.NewGuid()); string contentType = "multipart/form-data; boundary=" + text;//multipart类型 byte[] multipartFormData = HttpHelper4MultipartForm.GetMultipartFormData(postParameters, text); return HttpHelper4MultipartForm.PostForm(postUrl, userAgent, contentType, multipartFormData); } private static HttpWebResponse PostForm(string postUrl, string userAgent, string contentType, byte[] formData) { HttpWebRequest httpWebRequest = WebRequest.Create(postUrl) as HttpWebRequest; if (httpWebRequest == null) { throw new NullReferenceException("request is not a http request"); }              httpWebRequest.Method = "POST";//post方式             httpWebRequest.SendChunked = false;             httpWebRequest.KeepAlive = true;             httpWebRequest.Proxy = null;             httpWebRequest.Timeout = Timeout.Infinite;             httpWebRequest.ReadWriteTimeout = Timeout.Infinite;             httpWebRequest.AllowWriteStreamBuffering = false;             httpWebRequest.ProtocolVersion = HttpVersion.Version11;             httpWebRequest.ContentType = contentType;             httpWebRequest.CookieContainer = new CookieContainer();             httpWebRequest.ContentLength = (long)formData.Length; try { using (Stream requestStream = httpWebRequest.GetRequestStream()) { int bufferSize = 4096; int position = 0; while (position < formData.Length) {                         bufferSize = Math.Min(bufferSize, formData.Length - position); byte[] data = new byte[bufferSize];                         Array.Copy(formData, position, data, 0, bufferSize);                         requestStream.Write(data, 0, data.Length);                         position += data.Length; }                     requestStream.Close(); } } catch (Exception ex) { return null; } HttpWebResponse result; try {                 result = (httpWebRequest.GetResponse() as HttpWebResponse); } catch (WebException arg_9C_0) {                 result = (arg_9C_0.Response as HttpWebResponse); } return result; } public static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) { return true; } /// <summary> /// 从表单中获取数据 /// </summary> /// <param name="postParameters"></param> /// <param name="boundary"></param> /// <returns></returns> private static byte[] GetMultipartFormData(Dictionary<string, object> postParameters, string boundary) { Stream stream = new MemoryStream(); bool flag = false; foreach (KeyValuePair<string, object> current in postParameters) { if (flag) {                     stream.Write(HttpHelper4MultipartForm.encoding.GetBytes("rn"), 0, HttpHelper4MultipartForm.encoding.GetByteCount("rn")); }                 flag = true; if (current.Value is HttpHelper4MultipartForm.FileParameter) { HttpHelper4MultipartForm.FileParameter fileParameter = (HttpHelper4MultipartForm.FileParameter)current.Value; string s = string.Format("--{0}rnContent-Disposition: form-data; name="{1}"; filename="{2}"rnContent-Type: {3}rnrn", new object[] {                         boundary,                         current.Key,                         fileParameter.FileName ?? current.Key,                         fileParameter.ContentType ?? "application/octet-stream" });                     stream.Write(HttpHelper4MultipartForm.encoding.GetBytes(s), 0, HttpHelper4MultipartForm.encoding.GetByteCount(s));                     stream.Write(fileParameter.File, 0, fileParameter.File.Length); } else { string s2 = string.Format("--{0}rnContent-Disposition: form-data; name="{1}"rnrn{2}", boundary, current.Key, current.Value);                     stream.Write(HttpHelper4MultipartForm.encoding.GetBytes(s2), 0, HttpHelper4MultipartForm.encoding.GetByteCount(s2)); } } string s3 = "rn--" + boundary + "--rn";             stream.Write(HttpHelper4MultipartForm.encoding.GetBytes(s3), 0, HttpHelper4MultipartForm.encoding.GetByteCount(s3));             stream.Position = 0L; byte[] array = new byte[stream.Length];             stream.Read(array, 0, array.Length);             stream.Close(); return array; } } } 

3.实现融合

此处我创建了一个方法，给定两个参数：模板图路径和融合图的路径，返回第三方接口反馈的结果字符串

 /// <summary> /// 调用三方接口实现图片合成 /// </summary> /// <param name="tempurl">人脸融合的模板图</param> /// <param name="mergeurl">人脸融合的融合图</param> [HttpPost] public string PostSend(string tempImg,string mergeImg) { try { //用来存储接口参数值                 Dictionary<string, object> verifyPostParameters = new Dictionary<string, object>(); var key = "xxxxxxxxxxxxxxxxx";//注册后得到的key var secret = "xxxxxxxxxxxxxxxxxxxxx";//注册后得到的secret //接口必须参数一                 verifyPostParameters.Add("api_key", key); //接口必须参数二                 verifyPostParameters.Add("api_secret", secret); //（模板图） Bitmap bmp = new Bitmap(tempImg); // 图片地址 byte[] fileImage; using (Stream stream1 = new MemoryStream()) {                     bmp.Save(stream1, ImageFormat.Jpeg); byte[] arr = new byte[stream1.Length];                     stream1.Position = 0;                     stream1.Read(arr, 0, (int)stream1.Length);                     stream1.Close();                     fileImage = arr; } //接口必须参数三 模板图的路径地址，必须以post multipart/form-data 的方式上传(此处通过调用HTTPHelper4MultipartForm的方法已实现)                 verifyPostParameters.Add("template_file", new HttpHelper4MultipartForm.FileParameter(fileImage, "1.jpg", "application/octet-stream")); //接口可选参数 脸部坐标位置                 verifyPostParameters.Add("template_rectangle", "415,225,402,402"); //（融合图） Bitmap bmp2 = new Bitmap(mergeImg); // 图片地址 byte[] fileImage2; using (Stream stream2 = new MemoryStream()) {                     bmp2.Save(stream2, ImageFormat.Jpeg); byte[] arr2 = new byte[stream2.Length];                     stream2.Position = 0;                     stream2.Read(arr2, 0, (int)stream2.Length);                     stream2.Close();                     fileImage2 = arr2; } //接口必须参数四 融合图的路径地址，必须以post multipart/form-data 的方式上传(此处通过调用HTTPHelper4MultipartForm的方法已实现)                 verifyPostParameters.Add("merge_file", new HttpHelper4MultipartForm.FileParameter(fileImage2, "2.jpg", "application/octet-stream")); //调用HttpHelper4MultipartForm的MultipartFormDataPost方法实现post提交并反馈第三方提供的返回结果 HttpWebResponse verifyResponse = HttpHelper4MultipartForm.MultipartFormDataPost("https://api-cn.faceplusplus.com/imagepp/v1/mergeface", "", verifyPostParameters); //此处获取反馈的流来读取json格式的字符串，因为图片的字符串非常的“大”，必须循环获取，此操作在HttpHelper4MultipartForm类的MultipartFormDataPost方法中已经实现，所以在调用反馈的字符串是这个地方只需将它全部读取。 var res = verifyResponse.GetResponseStream(); StreamReader sr = new StreamReader(res, Encoding.ASCII); string reslut= sr.ReadToEnd();                 sr.Close();                 res.Close();                 verifyResponse.Close(); return reslut; } catch (WebException ex) { HttpWebResponse res = (HttpWebResponse)ex.Response; Stream myResponseStream = res.GetResponseStream(); StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.Default); string retString = myStreamReader.ReadToEnd(); return retString; } } 

实现步骤：
（1）创建 Dictionary<string, object> verifyPostParameters = new Dictionary<string, object>();用来存储第三方接口所需的参数和值
（2）赋值 给所需的参数赋值：

var key = “xxxxxxxxxxxxxxxxx”;//注册后得到的key
var secret = “xxxxxxxxxxxxxxxxxxxxx”;//注册后得到的secret
verifyPostParameters.Add(“api_key”, key);//必须参数
verifyPostParameters.Add(“api_secret”, secret);//必须参数
verifyPostParameters.Add(“template_file”, new HttpHelper4MultipartForm.FileParameter(fileImage, “1.jpg”, “application/octet-stream”));//必须参数（模板图片文件） 需要post multipart/form-data 的方式上传
verifyPostParameters.Add(“template_rectangle”, “415,225,402,402”);//接口可选参数 脸部坐标位置
可以通过 接口”人脸位置检测”获取到脸部位置 https://www.faceplusplus.com.cn/face-detection/
verifyPostParameters.Add(“merge_file”, new HttpHelper4MultipartForm.FileParameter(fileImage2, “2.jpg”, “application/octet-stream”));//必须参数（融合图片文件） 需要post multipart/form-data 的方式上传

（3）调用 HttpHelper4MultipartForm类的MultipartFormDataPost实现发送请求和反馈结果

 HttpWebResponse verifyResponse = HttpHelper4MultipartForm.MultipartFormDataPost("https://api-cn.faceplusplus.com/imagepp/v1/mergeface", "", verifyPostParameters); 

（4）获取 读取反馈的流，得到json格式字符串，其中包含base64格式的图片字符串。
此处需注意要通过循环读取反馈的字符串，不然读取到的字符串不完整，出现一系列的报错。（此处已在HttpHelper4MultipartForm类中循环）

 var res = verifyResponse.GetResponseStream(); StreamReader sr = new StreamReader(res, Encoding.ASCII); string reslut= sr.ReadToEnd(); 

4.生成图片

 //模板图 var tempImg = Server.MapPath(@"~ImageTemplate1.jpg"); //融合图 var mergeImg = system.SourceFolder + "\" + imgname + ".jpg"; //调用三方接口生成字符串 string postset = PostSend(tempImg, mergeImg); //将得到的json格式字符串转换得到图片字符串 JObject read = JsonConvert.DeserializeObject<JObject>(postset); string resul = read["result"].ToString();//图片字符串 string err = read["error_message"].ToString();//错误信息 string id = read["request_id"].ToString();//所用时间 Bitmap Phon = ToImage(resul);//生成的图片 /// <summary> /// 将Base64字符串转换为图片 /// </summary> /// <param name="base64">base64格式图片字符串</param> private Bitmap ToImage(string base64) { try { byte[] bytes = Convert.FromBase64String(base64); MemoryStream ms = new MemoryStream();                 ms.Write(bytes, 0, bytes.Length); Bitmap bmp = new Bitmap(ms); return bmp; } catch (Exception ex) { throw ex; } } 

实现步骤：
（1）得到 模板图和融合图的图片文件路径地址；
（2）调用 生成反馈的字符串方法；

 string postset = PostSend(tempImg, mergeImg); 

（3）转换 将得到的json格式字符串转换成json，得到图片字符串和错误信息字符串，及其他反馈参数字符串；

 JObject read = JsonConvert.DeserializeObject<JObject>(postset); string resul = read["result"].ToString();//图片字符串 string err = read["error_message"].ToString();//错误信息 string id = read["request_id"].ToString();//所用时间 

（4）调用 转换成图片的方法；

 Bitmap Phon = ToImage(resul);//生成的图片 

帮助文档：
Merge Face API (V1): https://console.faceplusplus.com.cn/documents/20813963
注册帮助文档：https://console.faceplusplus.com.cn/documents/5671787
人脸位置检测： https://www.faceplusplus.com.cn/face-detection/
HttpHelper4MultipartForm类参考：https://console.faceplusplus.com.cn/documents/6329752