Opencv创建车牌图片识别系统方法详解

目录

• 前言
• 包含功能
• 软件版本
• 软件架构
• 参考文档
• 效果图展示
• 车牌检测过程
• 图片车牌文字识别过程
• 部分核心代码

前言

这是一个基于spring boot + maven + opencv 实现的图像识别及训练的Demo项目

包含车牌识别、人脸识别等功能，贯穿样本处理、模型训练、图像处理、对象检测、对象识别等技术点

java语言的深度学习项目，在整个开源社区来说都相对较少；

拥有完整的训练过程、检测、识别过程的开源项目更是少之又少！！

包含功能

• 蓝、绿、黄车牌检测及车牌号码识别
• 网上常见的轮廓提取车牌算法JAVA实现
• hsv色彩分割提取车牌算法JAVA实现
• 基于svm算法的车牌检测训练JAVA实现
• 基于ann算法的车牌号码识别训练JAVA实现
• 人脸检测 接下来将实现人脸识别
• 图片处理工具，目前实现了HSV色彩切割，后续将添加更多使用的图片处理工具，用于辅助算法优化

软件版本

• jdk 1.8.61+
• maven 3.0+
• opencv 4.0.1 ； javacpp1.4.4；opencv-platform 4.0.1-1.4.4
• spring boot 2.1.5.RELEASE
• yx-image-recognition 1.0.0版本

软件架构

B/S 架构，前端html + requireJS，后端java

数据库使用 sqlite3.0

接口文档使用swagger 2.0

参考文档

参考了EasyPR C++项目、以及fan-wenjie的EasyPR-Java项目；同时查阅了部分opencv官方4.0.1版本C++的源码，结合个人对java语言的理解，整理出当前项目

liuruoze/EasyPR

fan-wenjie/EasyPR-Java

opencv官方

效果图展示

车牌识别

黄牌识别

绿牌识别

夜间识别

图片提取工具

人脸识别

训练

接口文档

车牌检测过程

高斯模糊：

图像灰度化：

Sobel 算子：

图像二值化：

图像闭操作：

二值图像降噪：

提取外部轮廓：

外部轮廓筛选：

切图：

重置切图尺寸：

车牌检测结果:

图片车牌文字识别过程

车牌检测结果:

debug_char_threshold：

debug_char_clearLiuDing：

debug_specMat：

debug_chineseMat：

debug_char_auxRoi：

部分核心代码

package com.yuxue.service.impl;

import java.io.File;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Vector;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

import com.alibaba.druid.util.StringUtils;
import com.alibaba.fastjson.JSONObject;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.yuxue.constant.Constant;
import com.yuxue.entity.PlateFileEntity;
import com.yuxue.entity.TempPlateFileEntity;
import com.yuxue.enumtype.PlateColor;
import com.yuxue.mapper.PlateFileMapper;
import com.yuxue.mapper.TempPlateFileMapper;
import com.yuxue.service.PlateService;
import com.yuxue.util.FileUtil;
import com.yuxue.util.GenerateIdUtil;
import com.yuxue.util.PlateUtil;

@Service
public class PlateServiceImpl implements PlateService {

    @Autowired
    private PlateFileMapper plateFileMapper;

    @Autowired
    private TempPlateFileMapper tempPlateFileMapper;

    static {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public Object refreshFileInfo() {
        File baseDir = new File(Constant.DEFAULT_DIR);
        if(!baseDir.exists() || !baseDir.isDirectory()) {
            return null;
        }
        List<TempPlateFileEntity> resultList = Lists.newArrayList();

        // 获取baseDir下第一层级的目录， 仅获取文件夹，不递归子目录，遍历
        List<File> folderList = FileUtil.listFile(baseDir, ";", false);
        folderList.parallelStream().forEach(folder -> {
            if(!folder.getName().equals("temp")) {
                // 遍历每一个文件夹， 递归获取文件夹下的图片
                List<File> imgList = FileUtil.listFile(folder, Constant.DEFAULT_TYPE, true);
                if(null != imgList && imgList.size() > 0) {
                    imgList.parallelStream().forEach(n->{
                        TempPlateFileEntity entity = new TempPlateFileEntity();
                        entity.setFilePath(n.getAbsolutePath().replaceAll("\\\\", "/"));
                        entity.setFileName(n.getName());
                        entity.setFileType(n.getName().substring(n.getName().lastIndexOf(".") + 1));
                        resultList.add(entity);
                    });
                }
            }
        });

        tempPlateFileMapper.turncateTable();
        tempPlateFileMapper.batchInsert(resultList);
        tempPlateFileMapper.updateFileInfo();
        return 1;
    }

    @Override
    public Object recognise(String filePath, boolean reRecognise) {
        filePath = filePath.replaceAll("\\\\", "/");
        File f = new File(filePath);
        PlateFileEntity entity = null;

        Map<String, Object> paramMap = Maps.newHashMap();
        paramMap.put("filePath", filePath);
        List<PlateFileEntity> list= plateFileMapper.selectByCondition(paramMap);
        if(null == list || list.size() <= 0) {
            if(FileUtil.checkFile(f)) {
                entity = new PlateFileEntity();
                entity.setFileName(f.getName());
                entity.setFilePath(f.getAbsolutePath().replaceAll("\\\\", "/"));
                entity.setFileType(f.getName().substring(f.getName().lastIndexOf(".") + 1));
                plateFileMapper.insertSelective(entity);
            }
            reRecognise = true;
        } else {
            entity = list.get(0);
        }

        if(reRecognise || StringUtils.isEmpty(entity.getTempPath())) {
            doRecognise(f, entity); // 重新识别
            entity = plateFileMapper.selectByPrimaryKey(entity.getId()); // 重新识别之后，重新获取一下数据
        }
        // 查询debug文件
        if(!StringUtils.isEmpty(entity.getTempPath())) {
            Vector<String> debugFiles = new Vector<String>();
            FileUtil.getFiles(entity.getTempPath(), debugFiles);
            entity.setDebugFiles(debugFiles);
        }
        return entity;
    }

    @Override
    public Object recogniseAll() {
        // 查询到还没有进行车牌识别的图片
        List<PlateFileEntity> list = plateFileMapper.getUnRecogniseList();
        list.parallelStream().forEach(n->{
            File f = new File(n.getFilePath());
            if(FileUtil.checkFile(f)) {
                doRecognise(f, n);
            }
        });
        return 1;
    }

    /**
     * 单张图片 车牌识别
     * 拷贝文件到临时目录
     * 过程及结果更新数据库
     * @param f
     * @param e
     * @return
     */
    public Object doRecognise(File f, PlateFileEntity e) {
        if(!f.exists()) {
            return null;
        }

        String ct = GenerateIdUtil.getStrId();
        String targetPath = Constant.DEFAULT_TEMP_DIR + ct + (f.getName().substring(f.getName().lastIndexOf(".")));
        FileUtil.copyAndRename(f.getAbsolutePath(), targetPath); // 拷贝文件并且重命名

        // 创建临时目录， 存放过程图片
        String tempPath =  Constant.DEFAULT_TEMP_DIR + ct + "/";
        FileUtil.createDir(tempPath);
        e.setTempPath(tempPath);

        Boolean debug = false;
        Vector<Mat> dst = new Vector<Mat>();
        PlateUtil.getPlateMat(targetPath, dst, debug, tempPath);

        Set<String> plates = Sets.newHashSet();
        dst.stream().forEach(inMat -> {
            PlateColor color = PlateUtil.getPlateColor(inMat, true, false, tempPath);
            String plate = PlateUtil.charsSegment(inMat, color, debug, tempPath);
            plates.add("<" + plate + "," + color.desc + ">");
        });
        e.setRecoPlate(plates.toString());

        new File(targetPath).delete();  // 删除拷贝的临时文件
        plateFileMapper.updateByPrimaryKeySelective(e);
        return 1;
    }

    @Override
    public Object getImgInfo(String imgPath) {
        Map<String, Object> result = Maps.newHashMap();
        String ct = GenerateIdUtil.getStrId();
        File f = new File(imgPath);
        if(f.exists()) {
            String targetPath = Constant.DEFAULT_TEMP_DIR + ct + (f.getName().substring(f.getName().lastIndexOf(".")));
            FileUtil.copyAndRename(f.getAbsolutePath(), targetPath);
            result.put("targetPath", targetPath);   // 返回临时路径给前端
            // 获取图片的基本信息
            Mat inMat = Imgcodecs.imread(targetPath);
            result.put("rows", inMat.rows());
            result.put("cols", inMat.cols());
        }
        return result;
    }

    @Override
    public Object getHSVValue(String imgPath, Integer row, Integer col) {
        Map<String, Object> result = Maps.newHashMap();
        Mat inMat = Imgcodecs.imread(imgPath);

        double[] rgb = inMat.get(row, col);
        result.put("RGB", JSONObject.toJSONString(rgb));

        Mat dst = new Mat(inMat.rows(), inMat.cols(), CvType.CV_32FC3);
        Imgproc.cvtColor(inMat, dst, Imgproc.COLOR_BGR2HSV); // 转到HSV空间进行处理

        double[] hsv = dst.get(row, col);
        result.put("HSV", (int)hsv[0] + ", " + (int)hsv[1] + ", " + (int)hsv[2]);
        return result;
    }

}

package com.znz.service.impl;

import com.znz.service.PlateTypeService;
import com.znz.entity.PlateTypeEntity;
import com.znz.mapper.PlateTypeMapper;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;

import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.annotation.Propagation;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.HashMap;
import java.util.Map;
import java.util.List;

/**
 * 服务实现层
 * @author znz
 * @date 2020-09-30T16:54:41.823
 */
@Service
public class PlateTypeServiceImpl implements PlateTypeService {

    @Autowired
    private PlateTypeMapper plateTypeMapper;

    @Override
    public PlateTypeEntity getByPrimaryKey(Integer id) {
        PlateTypeEntity entity = plateTypeMapper.selectByPrimaryKey(id);
        return entity;
    }

    @Override
    public PageInfo<PlateTypeEntity> queryByPage(Integer pageNo, Integer pageSize, Map<String, Object> map) {
    	PageHelper.startPage(pageNo, pageSize);
		PageInfo<PlateTypeEntity> page = new PageInfo(plateTypeMapper.selectByCondition(map));
		return page;
    }

    @Override
    public List<PlateTypeEntity> queryByCondition(Map<String, Object> map) {
		return plateTypeMapper.selectByCondition(map);
    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public Map<String, Object> save(PlateTypeEntity plateTypeEntity) {
    	plateTypeEntity.setId(0);
    	plateTypeMapper.insertSelective(plateTypeEntity);

    	Map<String, Object> result = new HashMap<>();
    	result.put("id" , plateTypeEntity.getId());
    	return result;
    }

    @Override
	@Transactional(propagation = Propagation.REQUIRED)
	public Integer deleteById(Integer id){
		return plateTypeMapper.deleteByPrimaryKey(id);
	}

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public Integer updateById(PlateTypeEntity plateTypeEntity) {
    	if(null == plateTypeEntity || plateTypeEntity.getId() <= 0){
    		return 0;
    	}
    	return plateTypeMapper.updateByPrimaryKeySelective(plateTypeEntity);
    }

}

package com.znz.service.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.znz.entity.SystemMenuEntity;
import com.znz.mapper.SystemMenuMapper;
import com.znz.service.SystemMenuService;

import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.annotation.Propagation;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 服务实现层
 * @author znz
 * @date 2021-06-20 16:15:23
 */
@Service
public class SystemMenuServiceImpl  implements SystemMenuService {

    @Autowired
    private SystemMenuMapper systemMenuMapper;

    @Override
    public SystemMenuEntity getByPrimaryKey(Integer id) {
        SystemMenuEntity entity = systemMenuMapper.selectByPrimaryKey(id);
        return entity;
    }

    @Override
    public PageInfo<SystemMenuEntity> queryByPage(Integer pageNo, Integer pageSize, Map<String, Object> map) {
    	PageHelper.startPage(pageNo, pageSize);
		PageInfo<SystemMenuEntity> page = new PageInfo(systemMenuMapper.selectByCondition(map));
		return page;
    }

    @Override
	public List<SystemMenuEntity> queryByCondition(Map<String, Object> map) {
		return systemMenuMapper.selectByCondition(map);
	}

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public Map<String, Object> save(SystemMenuEntity entity) {
    	entity.setId(0);
    	systemMenuMapper.insertSelective(entity);

    	Map<String, Object> result = new HashMap<>();
    	result.put("id" , entity.getId());
    	return result;
    }

	@Override
	@Transactional(propagation = Propagation.REQUIRED)
	public Integer deleteById(Integer id){
		return systemMenuMapper.deleteByPrimaryKey(id);
	}

	@Override
    @Transactional(propagation = Propagation.REQUIRED)
    public Integer updateById(SystemMenuEntity systemMenuEntity) {
    	if(null == systemMenuEntity || systemMenuEntity.getId() <= 0){
    		return 0;
    	}
    	return systemMenuMapper.updateByPrimaryKeySelective(systemMenuEntity);
    }

	@Override
    public Object getUserMenu() {
        Map<String, Object> map = Maps.newHashMap();
        map.put("showFlag", 1);
        List<SystemMenuEntity> menus = systemMenuMapper.selectByCondition(map);

        //按层级封装，最多三级
        Map<String, Object> result = Maps.newHashMap();

        result.put("first", menus.stream().filter(n -> {
            return n.getMenuLevel() == 1;
        }));
        result.put("second", menus.stream().filter(n -> {
            return n.getMenuLevel() == 2;
        }));
        result.put("third", menus.stream().filter(n -> {
            return n.getMenuLevel() == 3;
        }));
        return result;
    }

}

package com.znz.service.impl;

import java.io.File;
import java.util.List;

import org.springframework.stereotype.Service;

import com.alibaba.druid.util.StringUtils;
import com.alibaba.fastjson.JSONObject;
import com.google.common.collect.Lists;
import com.znz.constant.Constant;
import com.znz.exception.ResultReturnException;
import com.znz.service.FileService;
import com.znz.util.FileUtil;

@Service
public class FileServiceImpl implements FileService {

    @Override
    public List<JSONObject> getFileTreeByDir(String rootPath, String dir, String typeFilter) {

        if(StringUtils.isEmpty(dir)){
            if(StringUtils.isEmpty(rootPath)){
                dir = Constant.DEFAULT_DIR;
            } else {
                dir = rootPath;
            }
        }
        if(StringUtils.isEmpty(typeFilter)){
            typeFilter = Constant.DEFAULT_TYPE;
        }

        File f = new File(dir);
        List<File> list = FileUtil.listFile(f, typeFilter, false);
        List<JSONObject> result = Lists.newArrayList();
        list.stream().forEach(n->{
            JSONObject jo = new JSONObject();
            jo.put("id", n.getAbsolutePath());
            jo.put("pid", n.getParentFile().getAbsolutePath());
            jo.put("filePath", n.getAbsolutePath());
            jo.put("fileName", n.getName());
            jo.put("isDir", n.isDirectory());
            result.add(jo);
        });
        return result;
    }

    @Override
    public File readFile(String filePath) {

        File f = new File(filePath);
        if(!f.exists() || f.isDirectory()) {
            throw new ResultReturnException("filePath参数异常，找不到指定的文件: " + filePath);
        }

        if(!f.exists() || f.isDirectory()) {
            throw new ResultReturnException("读取图片异常：" + f.getName());
        }
        return f;
    }

}

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