【车牌识别】基于matlab GUI模板匹配车牌识别【含Matlab源码 958期】

一、简介

1 读取拍摄图像—>截取车牌部分—>识别车牌
2 图像预处理：
将图像经过图像灰度化、图像增强、边缘提取、二值化等操作，转换成便于车牌定位的二值化图像；
3 车牌定位：
利用车牌的边缘、形状等特征，再结合Roberts 算子边缘检测、数字图像、形态学等技术对车牌进行定位；
4 字符的分割：
采用的方法是将二值化后的车牌部分进行寻找连续有文字的块，若长度大于设定的阈值则切割，从而完成字符的分割；
5 字符识别：
运用模板匹配算法完成。

思路一：
读取图像:：同上
截取车牌:：基于HSV色域和SOBEL边缘提取车牌
识别车牌:：将截取的车牌图像变换为二值图像, 切割之后与模板库叠加/相减(相同大小20*40)比例最高者就是对应字符

二、源代码

% ******************************************************
% 
% time  : 2021/05/26 17:12
% tip   : 车牌识别
% change: 
% *******************************************************
function varargout = CarId(varargin)
% CARID MATLAB code for CarId.fig
%      CARID, by itself, creates a new CARID or raises the existing
%      singleton*.
%
%      H = CARID returns the handle to a new CARID or the handle to
%      the existing singleton*.
%
%      CARID('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in CARID.M with the given input arguments.
%
%      CARID('Property','Value',...) creates a new CARID or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before CarId_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to CarId_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 CarId

% Last Modified by GUIDE v2.5 26-May-2021 20:30:44

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @CarId_OpeningFcn, ...
                   'gui_OutputFcn',  @CarId_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 CarId is made visible.
function CarId_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 CarId (see VARARGIN)

% Choose default command line output for CarId
handles.output = hObject;


%隐藏坐标轴
set(handles.axes1,'visible','off');
set(handles.axes2,'visible','off');
set(handles.axes3,'visible','off');
set(handles.axes4,'visible','off');
set(handles.axes5,'visible','off');
set(handles.axes6,'visible','off');
set(handles.axes7,'visible','off');
set(handles.axes8,'visible','off');
set(handles.axes9,'visible','off');
set(handles.axes10,'visible','off');
set(handles.axes11,'visible','off');
set(handles.axes12,'visible','off');


% Update handles structure
guidata(hObject, handles);

% UIWAIT makes CarId wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = CarId_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;

%======================my code========================%
% tip : 被删除的callback自己手动添加一下...55555.....
function openLocal_Callback(hObject,eventdata,handles)
[filename, pathname]=uigetfile({
     '*.jpg; *.png; *.bmp; *.tif';'*.png';'All Image Files';'*.*'},'请选择图片路径');
if pathname==0
    return;
end
I=imread([pathname filename]);
%显示原图
    axes(handles.axes1)     %将Tag值为axes1的坐标轴置为当前
    imshow(I,[]);   %解决图像太大无法显示的问题.why?貌似会自动缩放
    title('原图');
    handles.I=I;        %更新图像
% Update handles structure
guidata(hObject, handles);

function openCamera_Callback(hObject,eventdata,handles)
    imaqhwinfo
    vid = videoinput('winvideo',1);
    usbVidRes1=get(vid,'videoResolution');%获取视频的尺寸
    nBands1=get(vid,'NumberOfBands');%采集视频的颜色通道
    axes(handles.axes1);
    hImage1=imshow(zeros(usbVidRes1(2),usbVidRes1(1),nBands1));
    preview(vid,hImage1);
    handles.vid=vid;
% Update handles structure
guidata(hObject, handles);

function btnTakePhoto_Callback(hObject,eventdata,handles)
    vid=handles.vid;
    frame = getsnapshot(vid);
    axes(handles.axes1);
    imwrite(frame,'I.png');
    I=imread('I.png');
    axes(handles.axes1)     %将Tag值为axes1的坐标轴置为当前
    imshow(I,[]);   %解决图像太大无法显示的问题.why?貌似会自动缩放
    title('拍摄完成');
    handles.I=I;     %更新原图
% Update handles structure
guidata(hObject, handles);

%下面在使用原图方法: handles.I


% --- Executes on button press in btnGray2.
function btnGray2_Callback(hObject, eventdata, handles)
% hObject    handle to btnGray2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
    I=handles.Cut;
    I = rgb2gray(I);
    axes(handles.axes8)     %将Tag值为axes1的坐标轴置为当前
    imshow(I,[]);   %解决图像太大无法显示的问题.why?貌似会自动缩放
    title('灰度处理');
    handles.gray2=I;     %更新原图
% Update handles structure
guidata(hObject, handles);


% --- Executes on button press in btnBalance.
function btnBalance_Callback(hObject, eventdata, handles)
% hObject    handle to btnBalance (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
    I=handles.gray2;
    I = histeq(I);
    axes(handles.axes9)     %将Tag值为axes1的坐标轴置为当前
    imshow(I,[]);   %解决图像太大无法显示的问题.why?貌似会自动缩放
    title('直方图均衡化');
    handles.balance=I;     %更新原图
% Update handles structure
guidata(hObject, handles);


% --- Executes on button press in btnDouble.
function btnDouble_Callback(hObject, eventdata, handles)
% hObject    handle to btnDouble (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
    I=handles.balance;
    I = im2bw(I, 0.76);
    axes(handles.axes10)     %将Tag值为axes1的坐标轴置为当前
    imshow(I,[]);   %解决图像太大无法显示的问题.why?貌似会自动缩放
    title('图像二值化');
    handles.double=I;     %更新原图
% Update handles structure
guidata(hObject, handles);


% --- Executes on button press in btnMid.
function btnMid_Callback(hObject, eventdata, handles)
% hObject    handle to btnMid (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
    I=handles.double;
    I = medfilt2(I);
    axes(handles.axes11)     %将Tag值为axes1的坐标轴置为当前
    imshow(I,[]);   %解决图像太大无法显示的问题.why?貌似会自动缩放
    title('中值滤波');
    handles.Mid=I;     %更新原图
% Update handles structure
guidata(hObject, handles);


% --- Executes on button press in btnCut2.
function btnCut2_Callback(hObject, eventdata, handles)
% hObject    handle to btnCut2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
I=handles.Mid;
I = my_imsplit(I);  %切割图像
[m, n] = size(I);

s = sum(I);    %sum(x)就是竖向相加，求每列的和，结果是行向量;
j = 1;
k1 = 1;
k2 = 1;
while j ~= n
    while s(j) == 0
        j = j + 1;
    end
    k1 = j;
    while s(j) ~= 0 && j <= n-1
        j = j + 1;
    end
    k2 = j + 1;
    if k2 - k1 > round(n / 6.5)
        [val, num] = min(sum(I(:, [k1+5:k2-5])));
        I(:, k1+num+5) = 0;
    end
end

三、运行结果

四、备注

版本：2014a