Matlab中Slider和ButtonDownFcn的问题

Question

我遇到了Slider和ButtonDownFcn的问题。

目前我向用户显示GUI中的图像（使用GUIDE），然后我让他们通过在其周围画一个矩形来选择牌照。

我添加了滑块以度数转动图像。

当我转动图像然后单击它时，图像将返回其初始状态（角度）。

如何确保图像保留在其位置然后在其上绘制矩形？

这是我的ButtonDownFcn函数：

function axes1_ButtonDownFcn(hObject, eventdata, handles)
global image  h 
imshow(image, []);
h = imrect;
setColor(h, 'black');

这是我的滑块功能：

function slider2_Callback(hObject, eventdata, handles)
global image hImage
slider_value = get(handles.slider2,'Value');
axes(handles.axes1);
hImage = imshow(imrotate(image,slider_value,'bilinear'), 'Parent', handles.axes1);
set(hImage, 'ButtonDownFcn', @(s,e) axes1_ButtonDownFcn());

编辑：现在一切正常，更重要的是很明显。 最后一件事你知道如何从X轴和Y轴上移除数字。 我试过axes off，但没有帮助。

非常感谢。

Answer 1

我相信通过实例学习更容易。所以，我将继续我在previous question开始的示例。

启动GUI时，会显示一个图像，您可以使用滑块旋转图像。单击图像时，选择矩形ROI（您可以继续旋转下面的图像）。一旦满意，双击矩形，裁剪后的图像显示在其他轴上（一个从旋转的图像中裁剪，另一个从原始图像中裁剪），然后删除矩形。

function rotationGUI2()
    %# setup GUI
    hFig = figure('menu','none', 'Position',[100 100 750 420]);
    hAx = axes('Parent',hFig, 'Units','pixels', 'Position',[50 70 350 300]);
    hAx1 = axes('Parent',hFig, 'Units','pixels', 'Position',[450 230 250 140]);
    hAx2 = axes('Parent',hFig, 'Units','pixels', 'Position',[450 70 250 140]);
    uicontrol('Parent',hFig, 'Style','slider', 'Value',0, 'Min',0,...
        'Max',360, 'SliderStep',[1 10]./360, ...
        'Position',[100 20 300 30], 'Callback',@slider_callback) 
    hTxt = uicontrol('Style','text', 'String','0', ...
        'Units','pixels', 'Position',[240 25 20 15]);

    %# read and show image
    I = imread('cameraman.tif');
    hImg = imshow(I, 'Parent',hAx);
    set(hImg, 'ButtonDownFcn',@image_ButtonDownFcn);  %# attach event listener

    %# Callback functions
    function slider_callback(hObj, eventdata)
        angle = round( get(hObj,'Value') );             %# rotation angle
        I_rot = imrotate(I, angle, 'bilinear', 'crop'); %# rotate image
        set(hImg, 'CData',I_rot)                        %# update image
        set(hTxt, 'String',num2str(angle))              %# update text
    end
    function image_ButtonDownFcn(hObj,eventdata)
        hRect = imrect(hAx);
        setColor(hRect, 'black');
        rectPos = wait(hRect);
        delete(hRect)

        I1 = imcrop(I, rectPos);                  %# crop from original image
        I2 = imcrop(get(hImg,'CData'), rectPos);  %# crop from rotated image
        imshow(I1, 'Parent',hAx1)
        imshow(I2, 'Parent',hAx2)
    end
end

同样，使用GUIDE生成的图重新创建示例应该是类似的。 HTH

---

修改

您将在下面找到GUIDE生成的类似示例。和以前一样，您必须创建GUI并通过拖放添加组件。使用“Property Inspector”根据需要调整其属性。更重要的是，给每个人一个独特的Tag。我正在使用：

• imgAxis，cropAxis，processAxis
• loadButton，processButton
• angleSlider，angleText

最好不要使用全局变量，而是将数据存储在handles结构中，然后传递给回调函数。只需记住在任何更改其数据的方法的末尾调用guidata函数，以提交更改。

对于手动将处理程序附加到图像ButtonDownFcn事件的部分，您还应该将handles结构传递给参数列表。

那就是说，这里是GUI背后的代码（相关部分）：

%# --- Executes just before untitled is made visible.
function untitled_OpeningFcn(hObject, eventdata, handles, varargin)
    %# store handles to figure, axes, and others
    handles.fig = hObject;
    handles.hAx = findobj(hObject, 'Tag','imgAxis');
    handles.hAxCrop = findobj(hObject, 'Tag','cropAxis');
    handles.hAxProcess = findobj(hObject, 'Tag','processAxis');
    handles.img = [];
    handles.hImg = [];
    handles.hImgCrop = [];

    %# disable interaction of some components until image is loaded
    set(findobj(hObject, 'Tag','angleSlider'), 'Enable','off')
    set(findobj(hObject, 'Tag','processButton'), 'Enable','off')

    %# Update handles structure
    guidata(hObject, handles);
end

%# --- Outputs from this function are returned to the command line.
function varargout = untitled_OutputFcn(hObject, eventdata, handles)
    varargout{1} = handles.fig;
end

%# --- Executes on slider movement.
function angleSlider_Callback(hObject, eventdata, handles)
    angle = round( get(hObject,'Value') );                    %# rotation angle
    I_rot = imrotate(handles.img, angle, 'bilinear', 'crop'); %# rotate image
    set(handles.hImg, 'CData',I_rot)                          %# update image
    set(findobj(handles.fig,'Tag','angleText'), 'String',num2str(angle))
end

%# --- Executes on button press in processButton.
function processButton_Callback(hObject, eventdata, handles)
    %# get cropped image
    I = get(handles.hImgCrop, 'CData');

    %# do some processing: here i'm simply detecting the edges
    if isrgb(I), I = rgb2gray(I); end
    %#BW = im2bw(I, graythresh(I));
    BW = edge(I, 'canny');

    %# show processed image
    imshow(BW, 'Parent',handles.hAxProcess)

    %# Update handles structure
    guidata(hObject, handles);
end

%# --- Executes on button press in loadButton.
function loadButton_Callback(hObject, eventdata, handles)
    %# get image file location
    [fName, fPath] = uigetfile(...
        {'*.psd;*.bmp;*.jpg;*.tif;*.png;*.gif','All Image Files'; ...
        '*.*','All Files' }, 'File Selector', ...
        fullfile(matlabroot,'toolbox','images','imdemos'));
    if fPath==0
        msgbox('No file selected', 'File Selector', 'error');
        return
    end

    %# read and show image
    handles.img = imread( fullfile(fPath,fName) );
    handles.hImg = imshow(handles.img, 'Parent',handles.hAx);

    %# attach handler
    set(handles.hImg, 'ButtonDownFcn',{@imgAxis_ButtonDownFcn,handles});

    %# reenable disabled components
    set(findobj(handles.fig, 'Tag','angleSlider'), 'Enable','on')

    %# Update handles structure
    guidata(hObject, handles);
end

%# --- Executes on mouse press over axes background.
function imgAxis_ButtonDownFcn(hObject, eventdata, handles)
    %# check if some image is shown
    if isempty(handles.hImg) || ~ishandle(handles.hImg)
        return
    end

    %# select ROI using a rectangle
    hRect = imrect(handles.hAx);
    setColor(hRect, 'black');
    rectPos = wait(hRect);
    delete(hRect)

    %# crop image from rotated image, and show it
    I = imcrop(get(handles.hImg,'CData'), rectPos);
    handles.hImgCrop = imshow(I, 'Parent',handles.hAxCrop);

    %# reenable disabled components
    set(findobj(handles.fig, 'Tag','processButton'), 'Enable','on')

    %# Update handles structure
    guidata(hObject, handles);
end

我希望这一切都清楚

Answer 2

在axes1_ButtonDownFcn，imshow(image, []);行显示单击时未旋转的图像。我认为删除该行应该摆脱你的问题。然后，您可以使用gca代替您的轴。简而言之，试试这个

function axes1_ButtonDownFcn(hObject, eventdata, handles)
global image  h 
h = imrect(gca);
setColor(h, 'black');