首先訪問百度AI網站：https://cloud.baidu.com/，按照下圖的指示點開到應用管理的頁面。

穿件完成之後到管理中可以查看到對應的

添加工具類：

using System;
using System.IO;

namespace FaceCompare_Console
{
    class FileUtils
    {
        /// <summary>
        /// 返回路徑所指文件的base64編碼
        /// </summary>
        /// <param name="path"></param>
 

        /// <returns></returns>
        public static string getFileBase64(string path)
        {
            if (!File.Exists(path))
                return "";

            FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
            byte[] buffer = new byte[fs.Length];
            fs.Read(buffer, 
 
0, buffer.Length);
            fs.Close();
            return Convert.ToBase64String(buffer);
        }
    }
}

添加Token類：（註意：獲取的Token30天才會更新一次，因此最好不要每次都獲取，而是應該獲取一次存儲在本地，30天後再更新）

using System;
using System.Collections.Generic;
using System.Net.Http;

namespace FaceCompare_Console
{
    public static class
 
 AccessToken
    {
        // 調用getAccessToken()獲取的 access_token建議根據expires_in 時間 設置緩存
        // 返回token示例
        public static String TOKEN = "24.4c28a8feedb8a2c71fa552522284641f.2592000.1546578079.282335-15054444";

        // 百度雲中開通對應服務應用的 API Key 建議開通應用的時候多選服務
        private static String clientId = "*********************";
        // 百度雲中開通對應服務應用的 Secret Key
        private static String clientSecret = "**********************";

        /// <summary>
        /// 獲取Token
        /// </summary>
        /// <returns></returns>
        public static String getAccessToken()
        {
            String authHost = "https://aip.baidubce.com/oauth/2.0/token";
            HttpClient client = new HttpClient();
            List<KeyValuePair<String, String>> paraList = new List<KeyValuePair<string, string>>();
            paraList.Add(new KeyValuePair<string, string>("grant_type", "client_credentials"));
            paraList.Add(new KeyValuePair<string, string>("client_id", clientId));
            paraList.Add(new KeyValuePair<string, string>("client_secret", clientSecret));

            HttpResponseMessage response = client.PostAsync(authHost, new FormUrlEncodedContent(paraList)).Result;
            String result = response.Content.ReadAsStringAsync().Result;
            LitJson.JsonData jd = LitJson.JsonMapper.ToObject(result);
            return jd["access_token"].ToString();
        }
    }
}

接下來是面部比對的代碼：

using System;
using System.IO;
using System.Net;
using System.Text;

namespace FaceCompare_Console
{
    class FaceMatch
    {
        /// <summary>
        /// 人臉比對
        /// </summary>
        /// <param name="token">token</param>
        /// <param name="img1">圖像1文件路徑</param>
        /// <param name="img2">圖像2文件路徑</param>
        /// <returns>json格式</returns>
        public static string match(string token, string img1, string img2)
        {
            string host = "https://aip.baidubce.com/rest/2.0/face/v3/match?access_token=" + token;
            Encoding encoding = Encoding.Default;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(host);
            request.Method = "post";
            request.KeepAlive = true;
            String str = "[{\"image\":\"" + FileUtils.getFileBase64(img1) + "\",\"image_type\":\"BASE64\",\"face_type\":\"LIVE\",\"quality_control\":\"LOW\",\"liveness_control\":\"NONE\"},{\"image\":\"" + FileUtils.getFileBase64(img2) + "\",\"image_type\":\"BASE64\",\"face_type\":\"LIVE\",\"quality_control\":\"LOW\",\"liveness_control\":\"NONE\"}]";
            byte[] buffer = encoding.GetBytes(str);
            request.ContentLength = buffer.Length;
            request.GetRequestStream().Write(buffer, 0, buffer.Length);
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.Default);
            string result = reader.ReadToEnd();
            Console.WriteLine("人臉對比:");
            Console.WriteLine(result);
            return result;
        }
    }
}

最後是主程序中調用比對程序進行比對：

using System;

namespace FaceCompare_Console
{
    class Program
    {
        static void Main(string[] args)
        {
            AccessToken.getAccessToken();
            FaceMatch.match(AccessToken.TOKEN, @"D:\Compare\web.jpg", @"D:\Compare\web1.jpg");
            Console.ReadKey();
        }
    }
}

輸出的結果如下：

score 是比對的結果分值，滿分100，根據比對的要求判斷分值多少屬於比對程序即可。

更加詳細的參數說明可以訪問官網查看：https://ai.baidu.com/docs#/Face-Match-V3/top

補充：代碼中用到Http.Net這些類可以去Nuget管理中在線查找並下載：

對返回結果的json格式需要解析的話也可以在Nuget中搜索Newtonsoft或者Litjson進行解析！

百度AI—人臉在線比對