|
EDA365欢迎您登录!
您需要 登录 才可以下载或查看,没有帐号?注册
x
& S" y; m4 O0 J( z
一、简介
% k4 b8 _6 y5 D5 ?" G3 l1 背景意义
& { R& n9 m3 l) P; ~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。
& Z" u2 a0 `: U0 j* D; ]7 K+ M. u) c5 r
2 理论基础7 J; b$ A- l, L9 ?( H
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。
" G& H5 f! y" k. {( K) K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。' z$ H) Q; n% `. t- F" {4 F
流程图如下:5 O! q0 _ s9 x6 j
; x+ J* R. A# l5 S% Y
4 c# z) c/ ?2 L# i) D, H3 算法流程
% s7 f3 M* E; ` k% {8 i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。
$ c- z1 O" m: t3 g7 O" t9 r. Y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
& W0 D% e5 r! d9 e; r# l进行对比,得到识别结果。6 F# t' C* h c0 o
( }6 [" J* e+ m; t, f" O二、源代码
( V ~4 L2 ]7 E6 c1 t- 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});
- 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 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-')];
- end
- for 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-')];
- end
- h = [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 choice
- case '是'
- close;
- otherwise
- return;
- end
- function 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* z: N5 t' F+ d# ^
A' e4 j/ w5 E' h- k1 S
* _1 o: Q/ O. {( A- F& c三、运行结果/ d" A0 D! K& _3 A- a6 c1 K! j# e
9 x( q9 ~5 k1 p9 i- L
$ ?8 R1 ]0 u) k
# O8 \" ]/ Z( x9 W7 j. a2 w( ]) c |
|