【开源】基于 C# 和 Halcon 机器视觉开发的车牌识别工具（附带源码）

项目介绍

halcon_chepai一款基于C#编程语言与Halcon机器视觉库的车牌识别系统。该系统利用Halcon强大的图像处理能力，结合C#的灵活性与易用性，实现了高效、准确的车牌识别功能。识别成功率高达90%。

注意：项目中只引用了HalconDotNet.dll，还需安装halcon环境，或将halcon的安装路径文件放到本项目debug里才能正常运行。

应用场景

• 智能交通系统：在交通监控、违章抓拍等场景中，自动识别车牌号码，辅助交通管理。
• 停车场管理：自动识别进出车辆的车牌，实现自动化停车计费与管理。
• 物流追踪：在物流园区或货运站，通过车牌识别追踪货物运输车辆。
• 安防监控：在重要区域或场所的出入口，通过车牌识别加强安全监控。

功能特点

• 高精度识别：利用Halcon先进的图像处理算法，实现高精度的车牌识别。
• 实时性强：优化算法与处理流程，确保系统实时响应，满足实时监控需求。
• 适应性强：能够适应不同光照条件、车牌类型与倾斜角度的车牌识别。
• 易用性高：提供友好的用户界面与简单的操作方式，降低使用门槛。

Halcon关键代码

dev_close_window()dev_clear_window()read_image(image,'C:/Users/Administrator/Desktop/halcon/chepai4.jpg')get_image_size(image,Width,Height)dev_open_window_fit_size(0,0,Width,Height,-1,-1,WindowHandle)dev_display(image)* 将图片转化为rgb三通道decompose3(image,r,g,b)* 转为hsv 色调 饱和度 明度值 trans_from_rgb(r,g,b,h,s,v,'hsv')* 提升图片对比度emphasize(s,ImageEmphasize,Width,Height,1)threshold(ImageEmphasize,Region,255,255)connection(Region,ConnectedRegions)closing_rectangle1(ConnectedRegions,RegionClosing,50,50)* 按照最大面积选 select_shape_std(RegionClosing,SelectedRegions,'max_area',70)* 填充选出区域的孔洞 fill_up(SelectedRegions,RegionFillUp)* 抠图 reduce_domain(ImageEmphasize,RegionFillUp,ImageReduced)* 抠出原图 reduce_domain(image,RegionFillUp,ImageReduced1)* 识别threshold(ImageReduced,Region1,0,100)* 打断连接区域connection(Region1,ConnectedRegions1)* 筛选显示区域 select_shape(ConnectedRegions1,SelectedRegions1,'area','and',4014,19840.76)* 排序区域 sort_region(SelectedRegions1,SortedRegions,'character','true','row')* 反转图片 invert_image(ImageReduced1,ImageInvert)* 开始识别 read_ocr_class_mlp('Industrial_0-9A-Z_NoRej.omc',OCRHandle)do_ocr_multi_class_mlp(SortedRegions,ImageInvert,OCRHandle,Class,Confidence)

功能截图

源码地址

https://gitee.com/ss123true/halcon_chepai

C#调用项目代码

界面

HalconDev类

using HalconDotNet;using System.Collections;using System.Collections.Generic;using System.Windows.Forms;using System.Windows.Forms.VisualStyles;public partial class HalconDev{private HTuple windowHandle;public List<string[]> action(int threhold_down, int threhold_up, int area_down,int area_up,PictureBox pcb,string path){List<string[]> dic = new List<string[]>();// Local iconic variables HObject ho_image,ho_r,ho_g,ho_b,ho_h,ho_s;HObject ho_v,ho_ImageEmphasize,ho_Region,ho_ConnectedRegions;HObject ho_RegionClosing,ho_SelectedRegions,ho_RegionFillUp;HObject ho_ImageReduced,ho_ImageReduced1,ho_Region1,ho_ConnectedRegions1;HObject ho_SelectedRegions1,ho_SortedRegions,ho_ImageInvert;// Local control variables HTuple hv_Width = newHTuple(),hv_Height = newHTuple();HTuple hv_WindowHandle = newHTuple(),hv_OCRHandle = newHTuple();HTuple hv_Class = newHTuple(),hv_Confidence = newHTuple();// Initialize local and output iconic variables HOperatorSet.GenEmptyObj(out ho_image);HOperatorSet.GenEmptyObj(out ho_r);HOperatorSet.GenEmptyObj(out ho_g);HOperatorSet.GenEmptyObj(out ho_b);HOperatorSet.GenEmptyObj(out ho_h);HOperatorSet.GenEmptyObj(out ho_s);HOperatorSet.GenEmptyObj(out ho_v);HOperatorSet.GenEmptyObj(out ho_ImageEmphasize);HOperatorSet.GenEmptyObj(out ho_Region);HOperatorSet.GenEmptyObj(out ho_ConnectedRegions);HOperatorSet.GenEmptyObj(out ho_RegionClosing);HOperatorSet.GenEmptyObj(out ho_SelectedRegions);HOperatorSet.GenEmptyObj(out ho_RegionFillUp);HOperatorSet.GenEmptyObj(out ho_ImageReduced);HOperatorSet.GenEmptyObj(out ho_ImageReduced1);HOperatorSet.GenEmptyObj(out ho_Region1);HOperatorSet.GenEmptyObj(out ho_ConnectedRegions1);HOperatorSet.GenEmptyObj(out ho_SelectedRegions1);HOperatorSet.GenEmptyObj(out ho_SortedRegions);HOperatorSet.GenEmptyObj(out ho_ImageInvert);if (HDevWindowStack.IsOpen()){HOperatorSet.CloseWindow(HDevWindowStack.Pop());}if (HDevWindowStack.IsOpen()){HOperatorSet.ClearWindow(HDevWindowStack.GetActive());}ho_image.Dispose();HOperatorSet.ReadImage(out ho_image,path);hv_Width.Dispose();hv_Height.Dispose();HOperatorSet.GetImageSize(ho_image,out hv_Width,out hv_Height);hv_WindowHandle.Dispose();HOperatorSet.OpenWindow(0,0,pcb.Width,pcb.Height,pcb.Handle,"visible","",out windowHandle);HDevWindowStack.Push(windowHandle);//将图片转化为rgb三通道 ho_r.Dispose();ho_g.Dispose();ho_b.Dispose();HOperatorSet.Decompose3(ho_image,out ho_r,out ho_g,out ho_b);//转为hsv 色调 饱和度 明度值 ho_h.Dispose();ho_s.Dispose();ho_v.Dispose();HOperatorSet.TransFromRgb(ho_r,ho_g,ho_b,out ho_h,out ho_s,out ho_v,"hsv");//提升图片对比度 ho_ImageEmphasize.Dispose();HOperatorSet.Emphasize(ho_s,out ho_ImageEmphasize,hv_Width,hv_Height,1);ho_Region.Dispose();HOperatorSet.Threshold(ho_ImageEmphasize,out ho_Region,255,255);ho_ConnectedRegions.Dispose();HOperatorSet.Connection(ho_Region,out ho_ConnectedRegions);ho_RegionClosing.Dispose();HOperatorSet.ClosingRectangle1(ho_ConnectedRegions,out ho_RegionClosing,50,50);//按照最大面积选 ho_SelectedRegions.Dispose();HOperatorSet.SelectShapeStd(ho_RegionClosing,out ho_SelectedRegions,"max_area",70);//填充选出区域的孔洞 ho_RegionFillUp.Dispose();HOperatorSet.FillUp(ho_SelectedRegions,out ho_RegionFillUp);//抠图 ho_ImageReduced.Dispose();HOperatorSet.ReduceDomain(ho_ImageEmphasize,ho_RegionFillUp,out ho_ImageReduced);//抠出原图 ho_ImageReduced1.Dispose();HOperatorSet.ReduceDomain(ho_image,ho_RegionFillUp,out ho_ImageReduced1);//识别 ho_Region1.Dispose();HOperatorSet.Threshold(ho_ImageReduced,out ho_Region1,threhold_down,threhold_up);// 0 100 //打断连接区域 ho_ConnectedRegions1.Dispose();HOperatorSet.Connection(ho_Region1,out ho_ConnectedRegions1);//筛选显示区域 ho_SelectedRegions1.Dispose();HOperatorSet.SelectShape(ho_ConnectedRegions1,out ho_SelectedRegions1,"area","and",area_down,area_up);//4014,19840.76 //排序区域 ho_SortedRegions.Dispose();HOperatorSet.SortRegion(ho_SelectedRegions1,out ho_SortedRegions,"character","true","row");//反转图片 ho_ImageInvert.Dispose();HOperatorSet.InvertImage(ho_ImageReduced1,out ho_ImageInvert);//开始识别 hv_OCRHandle.Dispose();HOperatorSet.ReadOcrClassMlp("Industrial_0-9A-Z_NoRej.omc",out hv_OCRHandle);hv_Class.Dispose();hv_Confidence.Dispose();HOperatorSet.DoOcrMultiClassMlp(ho_SortedRegions,ho_ImageInvert,hv_OCRHandle,out hv_Class,out hv_Confidence);if (HDevWindowStack.IsOpen()){dic.Clear();HOperatorSet.DispObj(ho_ImageReduced1,windowHandle);HOperatorSet.DispObj(ho_image,windowHandle);HOperatorSet.DispObj(ho_Region1,windowHandle);HOperatorSet.WriteString(windowHandle,hv_Class);string[] cls = hv_Class.ToSArr();string[] confidence = hv_Confidence.ToSArr();for(int i = 0;i< cls.Length;i++){dic.Add(new string[]{cls[i],confidence[i]});}}ho_image.Dispose();ho_r.Dispose();ho_g.Dispose();ho_b.Dispose();ho_h.Dispose();ho_s.Dispose();ho_v.Dispose();ho_ImageEmphasize.Dispose();ho_Region.Dispose();ho_ConnectedRegions.Dispose();ho_RegionClosing.Dispose();ho_SelectedRegions.Dispose();ho_RegionFillUp.Dispose();ho_ImageReduced.Dispose();ho_ImageReduced1.Dispose();ho_Region1.Dispose();ho_ConnectedRegions1.Dispose();ho_SelectedRegions1.Dispose();ho_SortedRegions.Dispose();ho_ImageInvert.Dispose();hv_Width.Dispose();hv_Height.Dispose();hv_WindowHandle.Dispose();hv_OCRHandle.Dispose();hv_Class.Dispose();hv_Confidence.Dispose();return dic;}}

Form1.cs

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;namespace halcon_chepai{public partial class Form1 : Form{private HalconDev halconDev;private int threhold_up_value = 100;private int threhold_down_value = 0;private int area_down_value = 4014;private int area_up_value = 19840;public Form1(){halconDev = newHalconDev();InitializeComponent();threshold_down.Value = threhold_down_value;threshold_up.Value = threhold_up_value;area_up.Value = area_up_value;area_down.Value = area_down_value;threhold_up_label.Text = threhold_up_label.Text +" : "+ threhold_up_value;threhold_down_label.Text = threhold_down_label.Text +" : "+threhold_down_value;area_down_label.Text = area_down_label.Text +" : "+ area_down_value;area_up_label.Text = area_up_label.Text +" : "+ area_up_value;}private void button1_Click(object sender, EventArgs e){try{var dic = halconDev.action(threhold_down_value,threhold_up_value,area_down_value,area_up_value,pictureBox1,textBox1.Text);listView1.Items.Clear();foreach(var i in dic){ListViewItem item = newListViewItem();item.SubItems.Add(i[1]);item.Text = i[0];listView1.Items.Add(item);}}catch (Exception ex){label1.Text = ex.Message;}}private void threshold_down_Scroll(object sender, EventArgs e){try{threhold_down_value = threshold_down.Value;threhold_down_label.Text = threhold_down_label.Text.Split(':')[0].Replace(" ","")+" : "+ threhold_down_value;var dic = halconDev.action(threhold_down_value,threhold_up_value,area_down_value,area_up_value,pictureBox1,textBox1.Text);listView1.Items.Clear();foreach (var i in dic){ListViewItem item = newListViewItem();item.SubItems.Add(i[1]);item.Text = i[0];listView1.Items.Add(item);}}catch(Exception ex){label1.Text = ex.Message;}}private void threshold_up_Scroll(object sender, EventArgs e){try{threhold_up_value = threshold_up.Value;threhold_up_label.Text = threhold_up_label.Text.Split(':')[0].Replace(" ","")+" : "+ threhold_up_value;var dic = halconDev.action(threhold_down_value,threhold_up_value,area_down_value,area_up_value,pictureBox1,textBox1.Text);listView1.Items.Clear();foreach (var i in dic){ListViewItem item = newListViewItem();item.SubItems.Add(i[1]);item.Text = i[0];listView1.Items.Add(item);}}catch (Exception ex){label1.Text = ex.Message;}}private void area_down_Scroll(object sender, EventArgs e){try{area_down_value = area_down.Value;area_down_label.Text = area_down_label.Text.Split(':')[0].Replace(" ","")+" : "+ area_down_value;var dic = halconDev.action(threhold_down_value,threhold_up_value,area_down_value,area_up_value,pictureBox1,textBox1.Text);listView1.Items.Clear();foreach (var i in dic){ListViewItem item = newListViewItem();item.SubItems.Add(i[1]);item.Text = i[0];listView1.Items.Add(item);}}catch (Exception ex){label1.Text = ex.Message;}}private void area_up_Scroll(object sender, EventArgs e){try{area_up_value = area_up.Value;area_up_label.Text = area_up_label.Text.Split(':')[0].Replace(" ","")+" : "+ area_up_value;var dic = halconDev.action(threhold_down_value,threhold_up_value,area_down_value,area_up_value,pictureBox1,textBox1.Text);listView1.Items.Clear();foreach (var i in dic){ListViewItem item = newListViewItem();item.SubItems.Add(i[1]);item.Text = i[0];listView1.Items.Add(item);}}catch(Exception ex){label1.Text = ex.Message;}}}}