C#身份证识别相关技术功能详解

最近研究c#相关的ocr技术，图像识别一般c和c++这种底层语言做的比较多，c#主要是依托一些封装好的组件进行调用，这里介绍一种身份证识别的方法。

环境搭建

下载地址：emgucv官网

在file类别下下载这个exe，进行安装，安装后在目录下能找相应组件，还有些应用的案例。

dll文件夹中的dll引用到c#项目中，x64，x86，tessdata对应ocr识别的类库和语言库，我tessdata中已添加中文语言包，将这三个文件夹放入程序执行文件夹中。

demo

自己做的小demo如图：身份证图片是百度上下载的

不得不说这个类库唯一弊端就是文字识别率太低，图像识别效果也不太好

using system;
using system.collections.generic;
using system.componentmodel;
using system.data;
using system.drawing;
using system.linq;
using system.text;
using system.threading.tasks;
using system.windows.forms;
using emgu.cv;
using emgu.cv.ocr;
using emgu.cv.structure;
using system.io;

namespace emgucv
{
 public partial class form1 : form
 {
  image<gray, byte> imagethreshold;
  public form1()
  {
   initializecomponent();
   picturebox1.enabled = false;
  }

  private void form1_load(object sender, eventargs e)
  {



  }

  private void button1_click(object sender, eventargs e)
  {
   //第一个参数是语言包文件夹的地址，不写默认在执行文件夹下
   tesseract _ocr = new tesseract(@"", "chi_sim", ocrenginemode.tesseractonly);
   _ocr.setimage(imagethreshold);
   _ocr.recognize();
   string text = _ocr.getutf8text();
   this.textbox1.text = text;
  }

  private void picturebox2_click(object sender, eventargs e)
  {
   openfiledialog of = new openfiledialog();
   of.title = "请选择图片";
   if (of.showdialog() == dialogresult.ok)
   {
    string file = of.filename;
    image img = image.fromfile(file);
    picturebox1.image = img;
   }
   bitmap bitmap = (bitmap)this.picturebox1.image;
   image<bgr, byte> imagesource = new image<bgr, byte>(bitmap);
   image<gray, byte> imagegrayscale = imagesource.convert<gray, byte>();
   imagegrayscale = randon(imagegrayscale);
   imagethreshold = imagegrayscale.thresholdbinary(new gray(100), new gray(255));
   this.picturebox2.image = imagethreshold.tobitmap();
  }
  /// <summary>
  /// 旋转校正
  /// </summary>
  /// <param name="imageinput"></param>
  /// <returns></returns>
  private image<gray, byte> randon(image<gray, byte> imageinput)//图像投影旋转法倾斜校正子函数定义
  {
   int nwidth = imageinput.width;
   int nheight = imageinput.height;
   int sum;
   int sumofcha;
   int sumofchatemp = 0;
   int[] sumhang = new int[nheight];
   image<gray, byte> resultimage = imageinput;
   image<gray, byte> imrotaimage;
   //20度范围内的调整
   for (int ang = -20; ang < 20; ang = ang + 1)
   {
    imrotaimage = imageinput.rotate(ang, new gray(1));
    for (int i = 0; i < nheight; i++)
    {
     sum = 0;
     for (int j = 0; j < nwidth; j++)
     {
      sum += imrotaimage.data[i, j, 0];
     }
     sumhang[i] = sum;
    }
    sumofcha = 0;
    for (int k = 0; k < nheight - 1; k++)
    {
     sumofcha = sumofcha + (math.abs(sumhang[k] - sumhang[k + 1]));
    }
    if (sumofcha > sumofchatemp)
    {
     resultimage = imrotaimage;
     sumofchatemp = sumofcha;
    }
   }
   return resultimage;
  }

  private void picturebox1_click(object sender, eventargs e)
  {

  }
 }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。