C#百度OCR-身份證圖片識別提取資訊
阿新 • • 發佈：2018-11-16
之前寫了一篇利用百度OCR進行本地和網路圖片識別文字的文章，點選檢視。今天補充識別身份證圖片的文章及demo
原始碼地址：https://download.csdn.net/download/horseroll/10681214
效果圖展示：
呼叫的是百度的API介面。API文件：http://ai.baidu.com/docs#/OCR-API/top
請求的URL地址（post）：https://aip.baidubce.com/rest/2.0/ocr/v1/idcard
請求引數：
返回引數：
1.首先先根據API key和Secret key得到token。API key和Secret key去百度雲的控制檯可以免費申請
string token=getAccessToken();// 呼叫getAccessToken()獲取的 access_token建議根據expires_in 時間 設定快取 // 返回token示例 public static String TOKEN = "24.adda70c11b9786206253ddb70affdc46.2592000.1493524354.282335-1234567"; // 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 = "cohIahxAt7HveHLYSHYK6G5N"; // 百度雲中開通對應服務應用的 Secret Key private static String clientSecret = "e8SAsDIWSK9NPUKviYiPQNlfaVDXQSY5"; public static String getAccessToken() { String authHost = "https://aip.baidubce.com/oauth/2.0/token"; //string result = ToolData.HttpPost(authHost, "grant_type=client_credentials&client_id="+clientId+"&client_secret="+clientSecret); 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; Console.WriteLine(result); return result; }
2.本地圖片進行上傳解析（POST提交）其實就是一句post程式碼
private void btnlocal_Click(object sender, EventArgs e) { OpenFileDialog filename = new OpenFileDialog(); filename.InitialDirectory = Application.StartupPath; filename.Filter = "All files(*.*)|*.*|image files|*.jpg;*.png;*.bmp"; filename.FilterIndex = 2; filename.RestoreDirectory = true; if (filename.ShowDialog() == DialogResult.OK) { //本地圖片.解析影象資料，base64編碼後進行urlencode，要求base64編碼和urlencode後大小不超過4M，最短邊至少15px，最長邊最大4096px,支援jpg/png/bmp格式，當image欄位存在時url欄位失效 bool cardjiaodu = cbjiaodu.Text == "true" ? true : false; string cardzhengfan= cbzhengfan.Text == "front" ? "front" : "back"; bool cardfengxian = cbfengxian.Text == "true" ? true : false; string local = filename.FileName.ToString();//本地圖片的路徑地址 tblocal.Text = local; string base64 = UrlEncode(ImgToBase64String(Image.FromFile(local))); string localpicure = ToolData.HttpPost("https://aip.baidubce.com/rest/2.0/ocr/v1/idcard", "access_token=" + token + "&detect_direction=" + cardjiaodu + "&id_card_side=" + cardzhengfan + "&image=" + base64 + "&detect_risk=" + cardfengxian); WriteTo(localpicure); pictureBox1.Image = Image.FromFile(local); } }
附帶上圖片轉base64程式碼
public String ImgToBase64String(Image bmp)
{
String strbaser64 = String.Empty;
var btarr = convertByte(bmp);
strbaser64 = Convert.ToBase64String(btarr);
return strbaser64;
}
/// <summary>
/// Image轉byte[]
/// </summary>
/// <param name="img">Img格式資料</param>
/// <returns>byte[]格式資料</returns>
public static byte[] convertByte(Image img)
{
MemoryStream ms = new MemoryStream();
img.Save(ms, img.RawFormat);
byte[] bytes = ms.ToArray();
ms.Close();
return bytes;
}
public static string UrlEncode(string str)
{
StringBuilder sb = new StringBuilder();
byte[] byStr = System.Text.Encoding.UTF8.GetBytes(str); //預設是System.Text.Encoding.Default.GetBytes(str)
for (int i = 0; i < byStr.Length; i++)
{
sb.Append(@"%" + Convert.ToString(byStr[i], 16));
}
return (sb.ToString());
}3.識別後的json內容進行輸出
/// <summary>
/// 在介面上顯示
/// </summary>
/// <param name="returnstr"></param>
public void WriteTo(string returnstr)
{
try
{
ReturnJsonForCard rj = CYQ.Data.Tool.JsonHelper.ToEntity<ReturnJsonForCard>(returnstr);
AReturnJsonForCard acj = CYQ.Data.Tool.JsonHelper.ToEntity<AReturnJsonForCard>(rj.words_result);
string resultstr = "";
resultstr += "姓名："+acj.姓名.words + "\r\n"+ "性別：" + acj.性別.words + "\r\n"+ "民族：" + acj.民族.words + "\r\n"+ "出生：" + acj.出生.words + "\r\n"+ "住址：" + acj.住址.words + "\r\n"+ "公民身份號碼：" + acj.公民身份號碼.words + "\r\n";
string card_direction = "";
if(rj.direction=="-1")
{
card_direction = "未定義";
}
else if (rj.direction == "0")
{
card_direction = "正向";
}
else if (rj.direction == "1")
{
card_direction = "逆時針90度";
}
else if (rj.direction == "2")
{
card_direction = "逆時針180度";
}
else if (rj.direction == "3")
{
card_direction = "逆時針270度";
}
resultstr += "影象方向：" + card_direction + "\r\n";
string card_image_status = "";
if(rj.image_status=="normal")
{
card_image_status = "識別正常";
}
else if(rj.image_status == "reversed_side")
{
card_image_status = "身份證正反面顛倒";
}
else if (rj.image_status == "non_idcard")
{
card_image_status = "上傳的圖片中不包含身份證";
}
else if (rj.image_status == "blurred")
{
card_image_status = "身份證模糊";
}
else if (rj.image_status == "other_type_card")
{
card_image_status = "其他型別證照";
}
else if (rj.image_status == "over_exposure")
{
card_image_status = "身份證關鍵欄位反光或過曝";
}
else if (rj.image_status == "unknown")
{
card_image_status = "未知狀態";
}
resultstr += "識別狀態：" + card_image_status + "\r\n";
string card_risk_type = "";
if (rj.risk_type == "normal")
{
card_risk_type = "正常";
}
else if(rj.risk_type == "copy")
{
card_risk_type = "影印件";
}
else if (rj.risk_type == "temporary")
{
card_risk_type = "臨時身份證";
}
else if (rj.risk_type == "screen")
{
card_risk_type = "翻拍";
}
else if (rj.risk_type == "unknown")
{
card_risk_type = "其他未知情況";
}
resultstr += "識別身份證型別：" + card_risk_type + "\r\n";
resultstr += "圖片編輯工具：" + rj.edit_tool + "\r\n";
richTextBox1.Clear();
richTextBox1.AppendText(resultstr);
}
catch (Exception ex)
{
MessageBox.Show("解析出錯，出錯原因：" + ex.Message);
}
}5.json字串的類
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace 百度OCR
{
public class ReturnJsonForCard
{
public string log_id { get; set; }
public string direction { get; set; }
public string image_status { get; set; }
public string risk_type { get; set; }
public string edit_tool { get; set; }
public string words_result_num { get; set; }
public string words_result { get; set; }
}
public class AReturnJsonForCard
{
public BReturnJsonForCard 住址 { get; set; }
public BReturnJsonForCard 出生 { get; set; }
public BReturnJsonForCard 姓名 { get; set; }
public BReturnJsonForCard 公民身份號碼 { get; set; }
public BReturnJsonForCard 性別 { get; set; }
public BReturnJsonForCard 民族 { get; set; }
}
public class BReturnJsonForCard
{
public string location { get; set; }
public string words { get; set; }
}
}
6.HttpPost方法。也可以自己用其他post方法
/// <summary>
/// HTTP POST方式請求資料
/// </summary>
/// <param name="url">URL.</param>
/// <param name="param">POST的資料</param>
/// <returns></returns>
public static string HttpPost(string url, string param)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.Accept = "*/*";
request.Timeout = 15000;
request.AllowAutoRedirect = false;
StreamWriter requestStream = null;
WebResponse response = null;
string responseStr = null;
try
{
requestStream = new StreamWriter(request.GetRequestStream());
requestStream.Write(param);
requestStream.Close();
response = request.GetResponse();
if (response != null)
{
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
responseStr = reader.ReadToEnd();
reader.Close();
}
}
catch (Exception)
{
throw;
}
finally
{
request = null;
requestStream = null;
response = null;
}
return responseStr;
}