前幾天在用MATLAB寫GUI軟件的過程中遇到了一些問題,在這裏分享一下,今天先講一下第一個問題就是GUI中圖像座標的獲取,今天先介紹第一個方法:ginput函數實現座標的獲取。
其實ginput函數就是獲取鼠標或者光標的圖像輸入,可以獲取圖像上的座標位置以及按鍵屬性,具體使用方法見MATLAB公司的幫助文檔,裏面介紹很詳細:
下面是GIF圖GUI的實現代碼:
function varargout = Getposition(varargin)
% GETPOSITION MATLAB code for Getposition.fig
% GETPOSITION, by itself, creates a new GETPOSITION or raises the existing
% singleton*.
%
% H = GETPOSITION returns the handle to a new GETPOSITION or the handle to
% the existing singleton*.
%
% GETPOSITION('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in GETPOSITION.M with the given input arguments.
%
% GETPOSITION('Property','Value',...) creates a new GETPOSITION or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before Getposition_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to Getposition_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 Getposition
% Last Modified by GUIDE v2.5 08-Apr-2019 13:13:02
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', @Getposition_OpeningFcn, ...
'gui_OutputFcn', @Getposition_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 Getposition is made visible.
function Getposition_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 Getposition (see VARARGIN)
% Choose default command line output for Getposition
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes Getposition wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = Getposition_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)
[pathname filename] = uigetfile({'*.jpg';'*.*'});
if isequal(filename,0)
warning off
imshow('trees.tif')
else
str = [pathname,filename];
pic = imread(str);
imshow(pic)
end
axes(handles.axes1)
while(1)
[x,y] = ginput();
set(handles.edit1,'string',x);
set(handles.edit2,'string',y);
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
function edit2_Callback(hObject, eventdata, handles)
% hObject handle to edit2 (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 edit2 as text
% str2double(get(hObject,'String')) returns contents of edit2 as a double
% --- Executes during object creation, after setting all properties.
function edit2_CreateFcn(hObject, eventdata, handles)
% hObject handle to edit2 (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
該方法雖然實現簡單,但是存在問題:
①十字光標於整個figure界面顯示,不美觀;
②可以獲取圖像顯示區域以外的座標,不符合使用要求;
③使用死循環進行不斷獲取座標,而死循環具有一定的風險性;
因此,後面將介紹其他方法獲取GUI圖像上的座標信息,大家可以根據使用情況選擇獲取方法~