最近研究c#相关的orc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，这里介绍三种身份证识别的方法。
一：调用大公司api接口，百度、云脉，文通科技都有相关的api介绍。
二：调用图像处理类库，emgucv是opencv的一个跨平台的.net封装，该封装也可以被编译到mono平台和允许在windows、mac os、android、iphone、ipad等多个平台上运行
三：调用office2007 组件
一、证件识别api接口
以聚合数据中的api接口为例，因为官方api没有提供c#的调用方式，网址如下：证件识别接口
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/// <summary>/// 上传图片/// </summary>/// <returns></returns>public static string cardupload(){try{string appkey = "网站自己申请的key"; //配置您申请的appkey httppostedfile file = httpcontext.current.request.files[0];string url = "http://api2.juheapi.com/cardrecon/upload";var parameters = new dictionary<string, string>();parameters.add("key", appkey);parameters.add("cardtype", "2");string result = httppostdata(url, 60000, "pic", file.inputstream, parameters);jobject info = jobject.parse(jobject.parse(result)["result"].tostring());var cardinfo = new{name = info["姓名"],card = info["公民身份号码"]};return cardinfo.tojson();}catch (exception ex){return ex.tostring();}}/// <summary>/// post调用api/// </summary>/// <param name="url">api地址</param>/// <param name="timeout">访问超时时间</param>/// <param name="filekeyname">文件参数名</param>/// <param name="file">文件流</param>/// <param name="stringdict">参数列表</param>/// <returns>结果集</returns>private static string httppostdata(string url, int timeout, string filekeyname,stream file, dictionary<string, string> stringdict){string responsecontent;var memstream = new memorystream();var webrequest = (httpwebrequest)webrequest.create(url);// 边界符var boundary = "---------------" + datetime.now.ticks.tostring("x");// 边界符var beginboundary = encoding.ascii.getbytes("--" + boundary + "\r\n");// 最后的结束符var endboundary = encoding.ascii.getbytes("--" + boundary + "--\r\n");// 设置属性webrequest.method = "post";webrequest.timeout = timeout;webrequest.contenttype = "multipart/form-data; boundary=" + boundary;//写入开始边界符memstream.write(beginboundary, 0, beginboundary.length);// 写入文件const string filepartheader ="content-disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n" +"content-type: application/octet-stream\r\n\r\n";var header = string.format(filepartheader, filekeyname, "card.jpg");var headerbytes = encoding.utf8.getbytes(header);memstream.write(headerbytes, 0, headerbytes.length);file.copyto(memstream);// 写入字符串的keyvar stringkeyheader = "\r\n--" + boundary +"\r\ncontent-disposition: form-data; name=\"{0}\"" +"\r\n\r\n{1}\r\n";foreach (byte[] formitembytes in from string key in stringdict.keysselect string.format(stringkeyheader, key, stringdict[key])into formitemselect encoding.utf8.getbytes(formitem)){memstream.write(formitembytes, 0, formitembytes.length);}// 写入最后的结束边界符memstream.write(endboundary, 0, endboundary.length);webrequest.contentlength = memstream.length;// 构造完毕，执行post方法var requeststream = webrequest.getrequeststream();memstream.position = 0;var tempbuffer = new byte[memstream.length];memstream.read(tempbuffer, 0, tempbuffer.length);memstream.close();requeststream.write(tempbuffer, 0, tempbuffer.length);requeststream.close();var httpwebresponse = (httpwebresponse)webrequest.getresponse();using (var httpstreamreader = new streamreader(httpwebresponse.getresponsestream(),encoding.getencoding("utf-8"))){responsecontent = httpstreamreader.readtoend();}httpwebresponse.close();webrequest.abort();return responsecontent;} |
二、emgucv类库调用
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。
c#进行识别，需进行图片二值化处理和ocr调用相关dll可在我整理的地址下载：360云盘 提取码：89f4
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
相关代码如下：
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using system;using system.collections.generic;using system.componentmodel;using system.data;using system.drawing;using system.linq;using system.text;using system.windows.forms;using emgu.cv;using emgu.cv.ocr;using emgu.cv.structure;using system.io;namespace imagemanage{public partial class form1 : form{image<gray, byte> imagethreshold;public form1(){initializecomponent();}private void btn_convert_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.recognize(imagethreshold);string text = _ocr.gettext();this.textbox1.text = text;}private void picturebox1_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;}}} |
三、office 2007组件
该组件免费而且识别度比较高。
环境搭建
office 2007组件modi，需要安装ofiice2007，且由于兼容性需要安装补丁，sp1或者sp2都行，补丁下载地址如下：
sp1下载地址 sp2下载地址
安装后控制面板-->卸载或更新程序-->选择office2007-->选择更改-->选择添加或修复功能-->弹出下面界面，运行相应组件。
将office工具-->microsoft office document imaging 下的工具运行
在c#项目中引用com组件即可：
如果office组件应用不是在本地程序而需要部署在iis上，还需将应用程序的应用池的权限设置为如下图所示：程序应用池-->高级设置-->标识
demo
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stringbuilder sb = new stringbuilder();modi.document doc = new modi.document();doc.create(fullfilename);modi.image image;modi.layout layout;doc.ocr(modi.milanguages.milang_chinese_simplified, true, true); // 识别文字类型for (int i = 0; i < doc.images.count; i++){image = (modi.image)doc.images[i];layout = image.layout;sb.append(layout.text);} |
以上即一些c#进行身份证识别的方法，可根据自己项目的不同需求进行选用。
原文链接：http://www.cnblogs.com/kaoleba/p/5662575.html
