1 简介
随着信息时代的到来,现代智能交通系统能够很轻易的识别出汽车牌照,这是智能交通管理的标志之一。智能交通管理系统的牌照识别集合了图像采集和预处理、车牌定位技术、字符分割和字符识别等相关技术。其中,车牌定位、字符分割和字符识别是最关键的技术,也是本次毕业设计的难点所在。正确利用好这三种关键技术,将有助于牌照识别的实时性和准确性,对于智能交通系统的实现有着决定性作用。在MATLAB软件开发环境下,系统首先对图像进行预处理、然后将预处理后的图像进行定位分割,最后识别出相应牌照上的字符,这样就可以模拟设计出汽车牌照识别系统。本文的图像预处理模块是将图像灰度化和用Canny算子进行边缘检测,汽车牌照定位依据是它的颜色特征,使用MATLAB中的Radon函数和Imrotate函数来进行车牌矫正;分割字符时,需要先找到连续的文字块,然后根据长度大小来确定是否分割,假如所找到的连续文字块的长度大于阈值,那么就表示可以对此文字块进行分割。并且为了能对车牌上的字符进行正确的识别,本文将采用BP神经网络算法。最后设计GUI界面,使界面更加简洁明了,便于操作。根据实验得出的结论,这种方式可以对蓝色的车牌进行高效、精确的识别,同时,也对光照、旋转和噪声表现出很好的鲁棒性,定位精度和识别正确率甚至可以超过90%。
2 部分代码
function varargout = run(varargin) % RUN MATLAB code for run.fig % RUN, by itself, creates a new RUN or raises the existing % singleton*. % % H = RUN returns the handle to a new RUN or the handle to % the existing singleton*. % % RUN('CALLBACK',hObject,eventData,handles,...) calls the local % function named CALLBACK in RUN.M with the given input arguments. % % RUN('Property','Value',...) creates a new RUN or raises the % existing singleton*. Starting from the left, property value pairs are % applied to the GUI before run_OpeningFcn gets called. An % unrecognized property name or invalid value makes property application % stop. All inputs are passed to run_OpeningFcn via varargin. % % *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one % instance to run (singleton)". % % See also: GUIDE, GUIDATA, GUIHANDLES % Edit the above text to modify the response to help run % Last Modified by GUIDE v2.5 07-May-2016 15:41:22 % Begin initialization code - DO NOT EDIT gui_Singleton = 1; gui_State = struct('gui_Name', mfilename, ... 'gui_Singleton', gui_Singleton, ... 'gui_OpeningFcn', @run_OpeningFcn, ... 'gui_OutputFcn', @run_OutputFcn, ... 'gui_LayoutFcn', [] , ... 'gui_Callback', []); if nargin && ischar(varargin{1}) gui_State.gui_Callback = str2func(varargin{1}); end if nargout [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:}); else gui_mainfcn(gui_State, varargin{:}); end % End initialization code - DO NOT EDIT % --- Executes just before run is made visible. function run_OpeningFcn(hObject, eventdata, handles, varargin) % This function has no output args, see OutputFcn. % hObject handle to figure % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % varargin command line arguments to run (see VARARGIN) % Choose default command line output for run handles.output = hObject; handles.cd0 = cd; handles.Color = 0; handles.I = []; axes(handles.axes1); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes2); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; %axes(handles.axes3); %set(gca,'Xtick',[]); %set(gca,'Ytick',[]); %box on; axes(handles.axes4); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes5); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes6); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes8); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes9); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes12); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes13); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes14); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes15); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes16); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; axes(handles.axes17); set(gca,'Xtick',[]); set(gca,'Ytick',[]); box on; % Update handles structure guidata(hObject, handles); % UIWAIT makes run wait for user response (see UIRESUME) % uiwait(handles.figure1); % --- Outputs from this function are returned to the command line. function varargout = run_OutputFcn(hObject, eventdata, handles) % varargout cell array for returning output args (see VARARGOUT); % hObject handle to figure % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % Get default command line output from handles structure varargout{1} = handles.output; % --- Executes on button press in pushbutton1. function pushbutton1_Callback(hObject, eventdata, handles) % hObject handle to pushbutton1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) %% 读图 [filename, cd1] = uigetfile( ... {'*.tif;*.TIF;*.JPG;*.jpg;*.bmp;*.BMP;*.jpeg;*.JPEG;','Image file';... '*.*', 'All file (*.*)'},'Pick an Image'); axes(handles.axes1); cla; axes(handles.axes2); cla; %axes(handles.axes3); %cla; axes(handles.axes4); cla; if filename cd(cd1); d = imread(filename); cd(handles.cd0); handles.I = d; axes(handles.axes1); imshow(d); handles.filename = filename; box on; end handles.Color = 0; cd(handles.cd0); set(handles.text2,'string',''); guidata(hObject, handles); % --- Executes on button press in pushbutton2. function pushbutton2_Callback(hObject, eventdata, handles) % hObject handle to pushbutton2 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) image = handles.I; gray = rgb2gray(image); % 图像灰度化 axes(handles.axes2); imshow(gray); % --- Executes on button press in pushbutton3. function pushbutton3_Callback(hObject, eventdata, handles) % hObject handle to pushbutton3 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) %image = handles.I; %gray = rgb2gray(image); %new_gray = histeq(gray); % 直方图均衡 ,图像增强 %axes(handles.axes3); %imshow(new_gray); % --- Executes on button press in pushbutton4. function pushbutton4_Callback(hObject, eventdata, handles) % hObject handle to pushbutton4 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) image = handles.I; gray = rgb2gray(image); new_gray = histeq(gray); % 直方图均衡 ,图像增强 if size(new_gray,1)>1000 new_gray_1 = imresize(new_gray,0.1); else new_gray_1 =new_gray; end bw = edge(new_gray_1,'canny'); axes(handles.axes4); imshow(bw); guidata(hObject, handles); % --- Executes on button press in pushbutton9. function pushbutton9_Callback(hObject, eventdata, handles) % hObject handle to pushbutton9 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) %% 字符识别 images_test_all = handles.testnum; nnmain; for i = 1:size(images_test_all,2) images_test = double(images_test_all(:,i)); pred(i) = predict(Theta1, Theta2, images_test'); end chepai = []; for i = 1:size(pred,2) if pred(i)>0 chepai = [chepai,Name{pred(i)}]; end end % chepai(1) = '苏'; set(handles.text2,'string',chepai); % --- Executes on button press in pushbutton10. function pushbutton10_Callback(hObject, eventdata, handles) % hObject handle to pushbutton10 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) %% 这个按钮关闭软件 close all; clear; clc;
3 仿真结果
4 参考文献
[1]冯知凡. 基于图像处理及BP神经网络的车牌识别技术的研究. Diss. 武汉科技大学, 2011.
部分理论引用网络文献,若有侵权联系博主删除。
5 MATLAB代码与数据下载地址
见博客主页头条