【实验内容】

用MATLAB的GUI程序设计一个具备图像边缘检测功能的用户界面，该设计程序有以下基本功能：

（1）图像的读取和保存。

（2）设计图形用户界面，让用户对图像进行彩色图像到灰度图像的转换，并显示原图和灰度图像。

（3）设计图形用户界面，让用户能够根据需要来选择边缘检测算子，即选择边缘检测的方法。

（4）设计图形用户界面，让用户能够自行设定检测的阈值和方向。

（5）显示边缘检测后的图像，并与原图和灰度图像进行对比。

【实验步骤】

1、建立菜单，选项包括“文件”（打开、保存、退出）、“检测方法”（sobel、prewitt、roberts、canny）和“帮助”。

建立3个坐标轴对象，用于显示原始图像、灰度图像和边缘检测后的图像。

建立1个按钮，用于将原始图像转换为灰度图像。

建立1个文本编辑框，用于输入数据。

建立菜单，选项包括“文件”（打开、保存、退出）、“检测方法”（sobel、prewitt、roberts、canny）和“帮助”。

五个静态文本框的string属性分别为“原图”、“灰度图像”、“检测图像”、“设定阈值”和“检测方向”。

三个坐标轴的Tag标识分别为original_image、gray_image、test_image。

按钮控件的string属性为“灰度转换”，Tag标识为rgbtogray。

文本编辑框的Tag标识为thresh_value。

列表框的string属性为horizontal、vertical、both，Tag标识为direction。

编写代码完成程序中的变量赋值、输入、输出等工作，打开对应文件，在对应函数位置添加如下程序，其他代码不变。

function varargout = m240531(varargin)
% M240531 MATLAB code for m240531.fig
%      M240531, by itself, creates a new M240531 or raises the existing
%      singleton*.
%
%      H = M240531 returns the handle to a new M240531 or the handle to
%      the existing singleton*.
%
%      M240531('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in M240531.M with the given input arguments.
%
%      M240531('Property','Value',...) creates a new M240531 or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before m240531_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to m240531_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 m240531% Last Modified by GUIDE v2.5 31-May-2024 11:43:02% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...'gui_Singleton',  gui_Singleton, ...'gui_OpeningFcn', @m240531_OpeningFcn, ...'gui_OutputFcn',  @m240531_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 m240531 is made visible.
function m240531_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 m240531 (see VARARGIN)% Choose default command line output for m240531
handles.output = hObject;% Update handles structure
guidata(hObject, handles);% UIWAIT makes m240531 wait for user response (see UIRESUME)
% uiwait(handles.figure1);% --- Outputs from this function are returned to the command line.
function varargout = m240531_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 rgbtogray.
function rgbtogray_Callback(hObject, eventdata, handles)
% hObject    handle to rgbtogray (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
gray=rgb2gray(handles.img)
set(handles.gray_image, 'HandleVisibility', 'ON');
axes(handles.gray_image)
imshow(gray);
handles.img=gray;
guidata(hObject,handles);function thresh_value_Callback(hObject, eventdata, handles)
% hObject    handle to thresh_value (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 thresh_value as text
%        str2double(get(hObject,'String')) returns contents of thresh_value as a double% --- Executes during object creation, after setting all properties.
function thresh_value_CreateFcn(hObject, eventdata, handles)
% hObject    handle to thresh_value (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 selection change in direction.
function direction_Callback(hObject, eventdata, handles)
% hObject    handle to direction (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)% Hints: contents = cellstr(get(hObject,'String')) returns direction contents as cell array
%        contents{get(hObject,'Value')} returns selected item from direction% --- Executes during object creation, after setting all properties.
function direction_CreateFcn(hObject, eventdata, handles)
% hObject    handle to direction (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called% Hint: popupmenu 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% --------------------------------------------------------------------
function Untitled_1_Callback(hObject, eventdata, handles)
% hObject    handle to Untitled_1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)% --------------------------------------------------------------------
function Untitled_2_Callback(hObject, eventdata, handles)
% hObject    handle to Untitled_2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)% --------------------------------------------------------------------
function Untitled_3_Callback(hObject, eventdata, handles)
% hObject    handle to Untitled_3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)% --------------------------------------------------------------------
function Sobel_Callback(hObject, eventdata, handles)
% hObject    handle to Sobel (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
v1=str2double(get(handles.thresh_value, 'string' ));
contents=get(handles.direction,'string');
v2=contents{(get(handles.direction,'value'))};
edge_sobel=edge(handles.img,'sobel',v1,v2);
set(handles.test_image, 'HandleVisibility','ON');
axes(handles.test_image);
imshow(edge_sobel)
handles.img=edge_sobel;
guidata(hObject,handles);% --------------------------------------------------------------------
function Prewitt_Callback(hObject, eventdata, handles)
% hObject    handle to Prewitt (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
v1=str2double(get(handles.thresh_value,'string'))
contents=get(handles.direction, 'string');
v2=contents{(get(handles.direction,'value' ))};
edge_prewitt=edge(handles.img, 'prewitt' ,v1,v2);
set(handles.test_image, 'HandleVisibility','ON');
axes(handles.test_image);
imshow(edge_prewitt)
handles.img=edge_prewitt;
guidata(hObject,handles);% --------------------------------------------------------------------
function Roberts_Callback(hObject, eventdata, handles)
% hObject    handle to Roberts (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
v1=str2double(get(handles.thresh_value,'string'))
contents=get(handles.direction, 'string');
v2=contents{(get(handles.direction,'value'))};
edge_roberts=edge(handles.img, 'roberts' ,v1,v2);
set(handles.test_image, 'HandleVisibility','ON');
axes(handles.test_image);
imshow(edge_roberts)
handles.img=edge_roberts;
guidata(hObject,handles);% --------------------------------------------------------------------
function Canny_Callback(hObject, eventdata, handles)
% hObject    handle to Canny (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
v1=str2double(get(handles.thresh_value, 'string'));
contents=get(handles.direction,'string');
v2=contents{(get(handles.direction,'value'))};
edge_canny=edge(handles.img,'canny',v1, v2);
set(handles.test_image, 'HandleVisibility','ON');
axes(handles.test_image);
imshow(edge_canny);
handles.img=edge_canny;
guidata(hObject,handles);% --------------------------------------------------------------------
function open_Callback(hObject, eventdata, handles)
% hObject    handle to open (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';'*.bmp';'*.tif';'*.*'},'载入图像');
if isequal(filename,0) || isequal(pathname,0)errordlg('没有选中文件','出错');return;
elsefile=[pathname,filename];global SS=file;x=imread(file);set(handles.original_image,'HandleVisibility','ON');axes(handles.original_image);imshow(x);handles.img=x;guidata(hObject,handles);
end% --------------------------------------------------------------------
function save_Callback(hObject, eventdata, handles)
% hObject    handle to save (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
[sfilename,sfilepath]=uiputfile({'*.jpg';'*.bmp';'*.tif';'*.*'}, ...'保存图像文件','untitled.jpg');
if ~isequal([sfilename,sfilepath],[0,0])sfileullname = [sfilepath,sfilename];imwrite(handles.img, sfilefullname);
elsemsgbox('你按了取消键','保存失败');
end% --------------------------------------------------------------------
function exit_Callback(hObject, eventdata, handles)
% hObject    handle to exit (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

1. 执行程序后，单击菜单栏中的文件，打开图片，在原图位置会显示彩色图像，单击“灰度转换”按钮，在灰度图像位置会显示转换后的灰度图像，在“设定阈值”框输入0.1，选择“检测方向”为both，再在“检测方法”菜单中选择Canny，即可在“检测图像”的位置显示边缘检测后的图像，最后在“文件”菜单中选择“保存”，即可保存最终分割后的边缘检测图。