【验证码识别】基于matlab GUI不变矩验证码识别（带面板）【含Matlab源码 095期】

一、不变矩验证码识别简介

1 背景意义
验证码具有多变性特点，而当前的识别系统往往具有很强的针对性，只能够识别某种类型的验证码。随着网络安全技术及验证码生成技术的不断发展，已经出现了更加复杂的验证码生成方法，如基于动态图像的验证码系统等。运用计算机视觉、模式识别等相关理论对多种不同类型的验证码进行识别研究。矩特征主要表征了图像区域的几何特征,又称为几何矩，由于其具有旋转、平移、尺度等特性的不变特征，所以又称其为不变矩。

2 理论基础
本案例提出了以处理颜色加噪的数字字符为理论研究素材，将模板匹配作为基本框架的验证码识别系统。本系统的优点在于能够对特定类型的数字验证码进行精确识别，实验中识别准确率可达到95％以上，并提供动态更新样本库的功能，可根据实际运行的环境提高验证码的识别率。
本案例选择了经典的数字验证码识别作为识别的对象。验证码的识别涉及图像预处理、分割、特征提取、识别等相关技术，本案例通过对彩色验证码图像进行灰度化、二值化、去噪和归一化等步骤来进行预处理，通过建立模板库的动态更新机制来提高系统的兼容性，进一步提升验证码识别的效率和准确性。
流程图如下：

3 算法流程
为了进行验证码识别，建立模板库建立动态模板库，加入自动更新的功能提高对数字验证码的识别率。数字验证码待识别对象即数字0 ~ 9，调用mkdir 函数来自动建立模板数据库文件夹。
由于图中有类似于椒盐噪声的带有颜色的噪声，数字验证码中的数字个数保持常量并且分布均匀、易于分割。因此，为了进行下一步的数字分割操作，需要先进行验证码图像去噪步骤。本案例采用颜色空间转换到hsv 的方式，用阈值过滤的手段进行去噪。进行图像去噪之后，可以发现验证码图像中的数字呈现分布均匀的状态，并且未明显受到倾斜、形变等因素的影响。借用数字图像二值化、积分投影的方式可对数字进行定位。在实际处理过程中，为了保证分割有效，加入了区域面积滤波操作，将剩余的噪声点进行滤除。为了进行下一步的识别操作，需要将分割结果进行归一化处理，整合成固定维数的数字集合。数字图像分割完成后，通过提取数字图像的不变矩特征信息，与模板库中的数字图像
进行对比，得到识别结果。

二、部分源代码

function varargout = daunxujian1(varargin)
% DAUNXUJIAN1 MATLAB code for daunxujian1.fig
%      DAUNXUJIAN1, by itself, creates a new DAUNXUJIAN1 or raises the existing
%      singleton*.
%
%      H = DAUNXUJIAN1 returns the handle to a new DAUNXUJIAN1 or the handle to
%      the existing singleton*.
%
%      DAUNXUJIAN1('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in DAUNXUJIAN1.M with the given input arguments.
%
%      DAUNXUJIAN1('Property','Value',...) creates a new DAUNXUJIAN1 or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before daunxujian1_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to daunxujian1_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 daunxujian1% Last Modified by GUIDE v2.5 23-Oct-2020 21:52:34% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...'gui_Singleton',  gui_Singleton, ...'gui_OpeningFcn', @daunxujian1_OpeningFcn, ...'gui_OutputFcn',  @daunxujian1_OutputFcn, ...'gui_LayoutFcn',  [] , ...'gui_Callback',   []);
if nargin && ischar(varargin{1})gui_State.gui_Callback = str2func(varargin{1});
endif nargout[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
elsegui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT% --- Executes just before daunxujian1 is made visible.
function daunxujian1_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 daunxujian1 (see VARARGIN)
% Choose default command line output for daunxujian1
handles.output = hObject;
handles.Result = [];
handles.File = [];
% Update handles structure
guidata(hObject, handles);
clc; warning off all;
InitAxes(handles);
% UIWAIT makes daunxujian1 wait for user response (see UIRESUME)
% uiwait(handles.figure1);% --- Outputs from this function are returned to the command line.
function varargout = daunxujian1_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)
[filename, pathname] = uigetfile({'*.jpg;*.tif;*.png;*.gif','All Image Files';...'*.*','All Files' },'载入图像',...fullfile(pwd, 'images'));
I = imread(fullfile(pathname, filename));
Result = Process_Main(I);
handles.File = fullfile(pathname, filename);
handles.Result = Result;
guidata(hObject, handles);
InitAxes(handles)
axes(handles.axes1); imshow(handles.Result.Image); title('原图像');% --- 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)
if ~isempty(handles.Result)axes(handles.axes1); imshow(handles.Result.Image); title('原图像');axes(handles.axes2); imshow(handles.Result.Medfilt); title('中值滤波图像');
end% --- 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)
if ~isempty(handles.Result)axes(handles.axes1); imshow(handles.Result.Image); title('原图像');axes(handles.axes2); imshow(handles.Result.Medfilt); title('中值滤波图像');axes(handles.axes3); imshow(handles.Result.Normalize); title('归一化图像');
end% --- 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)
if ~isempty(handles.Result)axes(handles.axes1); imshow(handles.Result.Image); title('原图像');axes(handles.axes2); imshow(handles.Result.Medfilt); title('中值滤波图像');axes(handles.axes3); imshow(handles.Result.Normalize); title('归一化图像');axes(handles.axes4); imshow(handles.Result.Bww); title('二值化图像');
end% --- Executes on button press in pushbutton6.
function pushbutton6_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton6 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if ~isempty(handles.Result)axes(handles.axes1); imshow(handles.Result.Image); title('原图像');axes(handles.axes2); imshow(handles.Result.Medfilt); title('中值滤波图像');axes(handles.axes3); imshow(handles.Result.Normalize); title('归一化图像');axes(handles.axes4); imshow(handles.Result.Bww); title('二值化图像');axes(handles.axes6); imshow(handles.Result.Thin); title('细化处理');axes(handles.axes5); imshow(handles.Result.Bw); title('特征提取');hold on;h = [];for i = 1 : length(handles.Result.hs) %绘制水平线h = [h plot([1 handles.Result.sz(2)], [handles.Result.hs(i) handles.Result.hs(i)], 'r-')];endfor i = 1 : length(handles.Result.vs)%绘制竖直线h = [h plot([handles.Result.vs(i) handles.Result.vs(i)], [1 handles.Result.sz(1)], 'g-')];endh = [h plot(handles.Result.x1, handles.Result.y1, 'y-')];%绘制左对角线h = [h plot(handles.Result.x2, handles.Result.y2, 'm-')];%绘制右对角线
end% --- Executes on button press in pushbutton7.
function pushbutton7_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton7 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
[filename, pathname] = uiputfile({'*.jpg;*.tif;*.png;*.gif','All Image Files';...'*.*','All Files' },'Save Image',...fullfile(pwd, 'Result/result.png'));
if ~isequal(filename, 0)imwrite(handles.Result.label, fullfile(pathname, filename));msgbox('保存图像成功！', '信息提示框');
end% --- 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)
choice = questdlg('确定退出?', ...'退出', ...'是','否','否');
switch choicecase '是'close;otherwisereturn;
endfunction edit1_Callback(hObject, eventdata, handles)
% hObject    handle to edit1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)% Hints: get(hObject,'String') returns contents of edit1 as text
%        str2double(get(hObject,'String')) returns contents of edit1 as a double% --- Executes during object creation, after setting all properties.
function edit1_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))set(hObject,'BackgroundColor','white');
end% --- Executes on button press in pushbutton8.
function pushbutton8_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton8 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
set(handles.edit1,'string',handles.Result.label);% --- 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)
if ~isempty(handles.Result)axes(handles.axes1); imshow(handles.Result.Image); title('原图像');axes(handles.axes2); imshow(handles.Result.Medfilt); title('中值滤波图像');axes(handles.axes3); imshow(handles.Result.Normalize); title('归一化图像');axes(handles.axes4); imshow(handles.Result.Bww); title('二值化图像');axes(handles.axes6); imshow(handles.Result.Thin); title('细化处理');
end

三、运行结果

四、matlab版本及参考文献

1 matlab版本
2014a

2 参考文献
[1] 蔡利梅.MATLAB图像处理——理论、算法与实例分析[M].清华大学出版社，2020.
[2]杨丹,赵海滨,龙哲.MATLAB图像处理实例详解[M].清华大学出版社，2013.
[3]周品.MATLAB图像处理与图形用户界面设计[M].清华大学出版社，2013.
[4]刘成龙.精通MATLAB图像处理[M].清华大学出版社，2015.