Matlab：在 GUI 中的两个图像上同时显示十字准线
Matlab: display crosshairs simultaneously on two images in GUI
我正在使用 GUIDE 构建一个 MATLAB GUI 来处理医学图像（MRI 扫描中的脑肿瘤分割）。作为预处理步骤，程序会注册不同的扫描，如下所示：
我现在想在两张图片上都显示十字准线，以目视检查配准。十字准线应该相互链接，以便它们指向两个图像中的相同像素。此外，当将鼠标悬停在（或单击）其中一张图像上时，它应该会移动。这就是我想要实现的目标：
是否存在可以实现此目的的内置 MATLAB 函数？或者，如果我必须自己编写，将如何解决这个问题？
我将使用 Toy GUI 来展示它的工作原理：
让我们首先尝试让它仅适用于第一张图片。你想要实现的是：
- 当用户点击图形时，我们想要获得鼠标点击的位置。
- 然后我们要检查点击是否位于第一张图片内
- 如果是，我们要更新横杆的位置，这将由叠加在图像上并在所选点交叉的两条线表示。
第 0 步：初始设置
你要先确认一些细节:
- 确保在两次
imshow 调用之后添加对 hold on 的调用，否则交叉栏将删除您的图像而不是叠加在图像上。
第一步：获取鼠标点击的位置
在您的 GUI 打开函数中（此处为 SuperDuperGUI_OpeningFcn），您想添加对 :
的调用
set(gcf, 'WindowButtonDownFcn', @getMousePositionOnImage);
这将在用户每次在您的 GUI 中单击时触发函数 getMousePositionOnImage。
然后，您要添加并实现函数 getMousePositionOnImage :
function getMousePositionOnImage(src, event)
% Fetch the current handles structure
handles = guidata(src);
% Get the coordinate IN THE AXES UNITS OF AXES1 (Here I chose to define them
% as pixels) of the point where the user clicked
cursorPoint = get(handles.axes1, 'CurrentPoint')
第 2 步：检查鼠标点击是否在第一张图片内
仍在getMousePositionOnImage函数中：
% Get the Position of the first image (We're only interested by the width
% and height of the axes1 object)
Img1Pos=get(handles.axes1,'Position')
% Check if inside
if(cursorPoint(1,1)<Img1Pos(3)&&cursorPoint(1,2)<Img1Pos(4)&&cursorPoint(1,1)>=0&&cursorPoint(1,2)>=0)
% Do stuff
end
第 3 步：如果点击在第一张图片内，更新横杆的位置
% Check if inside
if(cursorPoint(1,1)<Img1Pos(3)&&cursorPoint(1,2)<Img1Pos(4)&&cursorPoint(1,1)>=0&&cursorPoint(1,2)>=0)
Lines=findobj('Type','line','Parent',handles.axes1);
if isempty(Lines)
% If Lines is empty, we need to create the line objects
line([0 Img1Pos(3)],[cursorPoint(1,2) cursorPoint(1,2)],'Color','g','Parent',handles.axes1);
line([cursorPoint(1,1) cursorPoint(1,1)],[0 Img1Pos(4)],'Color','g','Parent',handles.axes1);
else
% If not, we just update the fields XData and YData of both Lines
Lines(1).XData=[0 Img1Pos(3)]; % Unnecessary but I'll leave it there for clarity
Lines(1).YData=[cursorPoint(1,2) cursorPoint(1,2)];
Lines(2).XData=[cursorPoint(1,1) cursorPoint(1,1)];
Lines(2).YData=[0 Img1Pos(4)]; % Unnecessary but I'll leave it there for clarity
end
end
结果：
现在我将让您完成最后一部分，其中涉及连接两个横杆。您将单独检查两者，而不是只检查点击是否在第一张图片上。然后，如果它在其中一张图片中，您将更新 both crossbar 到右轴对象中点击的位置
编辑
下面的代码是受 BillBokeey 的回答启发而来的，非常感谢。
首先，执行 BillBokeey 解决方案的第 0 步和第 1 步。然后我把这个函数放在我的代码中：
function getMousePositionOnImage(src, event)
% Fetch the current handles structure
handles = guidata(src);
% Get the coordinate IN THE AXES UNITS OF AXES1 (Here I chose to define them
% as pixels) of the point where the user clicked
cursorPoint1 = get(handles.axes2, 'CurrentPoint');
cursorPoint2 = get(handles.axes3, 'CurrentPoint');
% Get the Position of the first image (We're only interested by the width
% and height of the axes1 object)
Img1Pos = getpixelposition(handles.axes2);
Img2Pos = getpixelposition(handles.axes3);
XLim1 = get(handles.axes2, 'XLim');
YLim1 = get(handles.axes2, 'YLim');
XLim2 = get(handles.axes3, 'XLim');
YLim2 = get(handles.axes3, 'YLim');
% Check if inside
if (cursorPoint1(1)<XLim1(2) && cursorPoint1(2)<YLim1(2) && cursorPoint1(1)>=XLim1(1) && cursorPoint1(1)>=YLim1(1))
Lines1=findobj('Type','line','Parent',handles.axes2);
Lines2=findobj('Type','line','Parent',handles.axes3);
if isempty(Lines1)
% If Lines is empty, we need to create the line objects
line(XLim1,[cursorPoint1(1,2) cursorPoint1(1,2)],'Color','g','Parent',handles.axes2);
line([cursorPoint1(1,1) cursorPoint1(1,1)],YLim1,'Color','g','Parent',handles.axes2);
line(XLim2,[cursorPoint1(1,2) cursorPoint1(1,2)],'Color','g','Parent',handles.axes3);
line([cursorPoint1(1,1) cursorPoint1(1,1)],YLim2,'Color','g','Parent',handles.axes3);
else
% If not, we just update the fields XData and YData of both Lines
Lines1(1).XData=XLim1; % Unnecessary but I'll leave it there for clarity
Lines1(1).YData=[cursorPoint1(1,2) cursorPoint1(1,2)];
Lines1(2).XData=[cursorPoint1(1,1) cursorPoint1(1,1)];
Lines1(2).YData=YLim1; % Unnecessary but I'll leave it there for clarity
Lines2(1).XData=XLim2; % Unnecessary but I'll leave it there for clarity
Lines2(1).YData=[cursorPoint1(1,2) cursorPoint1(1,2)];
Lines2(2).XData=[cursorPoint1(1,1) cursorPoint1(1,1)];
Lines2(2).YData=YLim2; % Unnecessary but I'll leave it there for clarity
end
elseif (cursorPoint2(1)<XLim2(2) && cursorPoint2(2)<YLim2(2) && cursorPoint2(1)>=XLim2(1) && cursorPoint2(1)>=YLim2(1))
Lines1=findobj('Type','line','Parent',handles.axes2);
Lines2=findobj('Type','line','Parent',handles.axes3);
if isempty(Lines2)
% If Lines is empty, we need to create the line objects
line(XLim1,[cursorPoint2(1,2) cursorPoint2(1,2)],'Color','g','Parent',handles.axes2);
line([cursorPoint2(1,1) cursorPoint2(1,1)],YLim1,'Color','g','Parent',handles.axes2);
line(XLim2,[cursorPoint2(1,2) cursorPoint2(1,2)],'Color','g','Parent',handles.axes3);
line([cursorPoint2(1,1) cursorPoint2(1,1)],YLim2,'Color','g','Parent',handles.axes3);
else
% If not, we just update the fields XData and YData of both Lines
Lines1(1).XData=XLim1; % Unnecessary but I'll leave it there for clarity
Lines1(1).YData=[cursorPoint2(1,2) cursorPoint2(1,2)];
Lines1(2).XData=[cursorPoint2(1,1) cursorPoint2(1,1)];
Lines1(2).YData=YLim1; % Unnecessary but I'll leave it there for clarity
Lines2(1).XData=XLim2; % Unnecessary but I'll leave it there for clarity
Lines2(1).YData=[cursorPoint2(1,2) cursorPoint2(1,2)];
Lines2(2).XData=[cursorPoint2(1,1) cursorPoint2(1,1)];
Lines2(2).YData=YLim2; % Unnecessary but I'll leave it there for clarity
end
end
我正在使用 GUIDE 构建一个 MATLAB GUI 来处理医学图像（MRI 扫描中的脑肿瘤分割）。作为预处理步骤，程序会注册不同的扫描，如下所示：
我现在想在两张图片上都显示十字准线，以目视检查配准。十字准线应该相互链接，以便它们指向两个图像中的相同像素。此外，当将鼠标悬停在（或单击）其中一张图像上时，它应该会移动。这就是我想要实现的目标：
是否存在可以实现此目的的内置 MATLAB 函数？或者，如果我必须自己编写，将如何解决这个问题？
我将使用 Toy GUI 来展示它的工作原理：
让我们首先尝试让它仅适用于第一张图片。你想要实现的是：
- 当用户点击图形时，我们想要获得鼠标点击的位置。
- 然后我们要检查点击是否位于第一张图片内
- 如果是，我们要更新横杆的位置，这将由叠加在图像上并在所选点交叉的两条线表示。
第 0 步：初始设置
你要先确认一些细节:
- 确保在两次
imshow调用之后添加对hold on的调用，否则交叉栏将删除您的图像而不是叠加在图像上。
第一步：获取鼠标点击的位置
在您的 GUI 打开函数中（此处为 SuperDuperGUI_OpeningFcn），您想添加对 :
set(gcf, 'WindowButtonDownFcn', @getMousePositionOnImage);
这将在用户每次在您的 GUI 中单击时触发函数 getMousePositionOnImage。
然后，您要添加并实现函数 getMousePositionOnImage :
function getMousePositionOnImage(src, event)
% Fetch the current handles structure
handles = guidata(src);
% Get the coordinate IN THE AXES UNITS OF AXES1 (Here I chose to define them
% as pixels) of the point where the user clicked
cursorPoint = get(handles.axes1, 'CurrentPoint')
第 2 步：检查鼠标点击是否在第一张图片内
仍在getMousePositionOnImage函数中：
% Get the Position of the first image (We're only interested by the width
% and height of the axes1 object)
Img1Pos=get(handles.axes1,'Position')
% Check if inside
if(cursorPoint(1,1)<Img1Pos(3)&&cursorPoint(1,2)<Img1Pos(4)&&cursorPoint(1,1)>=0&&cursorPoint(1,2)>=0)
% Do stuff
end
第 3 步：如果点击在第一张图片内，更新横杆的位置
% Check if inside
if(cursorPoint(1,1)<Img1Pos(3)&&cursorPoint(1,2)<Img1Pos(4)&&cursorPoint(1,1)>=0&&cursorPoint(1,2)>=0)
Lines=findobj('Type','line','Parent',handles.axes1);
if isempty(Lines)
% If Lines is empty, we need to create the line objects
line([0 Img1Pos(3)],[cursorPoint(1,2) cursorPoint(1,2)],'Color','g','Parent',handles.axes1);
line([cursorPoint(1,1) cursorPoint(1,1)],[0 Img1Pos(4)],'Color','g','Parent',handles.axes1);
else
% If not, we just update the fields XData and YData of both Lines
Lines(1).XData=[0 Img1Pos(3)]; % Unnecessary but I'll leave it there for clarity
Lines(1).YData=[cursorPoint(1,2) cursorPoint(1,2)];
Lines(2).XData=[cursorPoint(1,1) cursorPoint(1,1)];
Lines(2).YData=[0 Img1Pos(4)]; % Unnecessary but I'll leave it there for clarity
end
end
结果：
现在我将让您完成最后一部分，其中涉及连接两个横杆。您将单独检查两者，而不是只检查点击是否在第一张图片上。然后，如果它在其中一张图片中，您将更新 both crossbar 到右轴对象中点击的位置
编辑
下面的代码是受 BillBokeey 的回答启发而来的，非常感谢。
首先，执行 BillBokeey 解决方案的第 0 步和第 1 步。然后我把这个函数放在我的代码中：
function getMousePositionOnImage(src, event)
% Fetch the current handles structure
handles = guidata(src);
% Get the coordinate IN THE AXES UNITS OF AXES1 (Here I chose to define them
% as pixels) of the point where the user clicked
cursorPoint1 = get(handles.axes2, 'CurrentPoint');
cursorPoint2 = get(handles.axes3, 'CurrentPoint');
% Get the Position of the first image (We're only interested by the width
% and height of the axes1 object)
Img1Pos = getpixelposition(handles.axes2);
Img2Pos = getpixelposition(handles.axes3);
XLim1 = get(handles.axes2, 'XLim');
YLim1 = get(handles.axes2, 'YLim');
XLim2 = get(handles.axes3, 'XLim');
YLim2 = get(handles.axes3, 'YLim');
% Check if inside
if (cursorPoint1(1)<XLim1(2) && cursorPoint1(2)<YLim1(2) && cursorPoint1(1)>=XLim1(1) && cursorPoint1(1)>=YLim1(1))
Lines1=findobj('Type','line','Parent',handles.axes2);
Lines2=findobj('Type','line','Parent',handles.axes3);
if isempty(Lines1)
% If Lines is empty, we need to create the line objects
line(XLim1,[cursorPoint1(1,2) cursorPoint1(1,2)],'Color','g','Parent',handles.axes2);
line([cursorPoint1(1,1) cursorPoint1(1,1)],YLim1,'Color','g','Parent',handles.axes2);
line(XLim2,[cursorPoint1(1,2) cursorPoint1(1,2)],'Color','g','Parent',handles.axes3);
line([cursorPoint1(1,1) cursorPoint1(1,1)],YLim2,'Color','g','Parent',handles.axes3);
else
% If not, we just update the fields XData and YData of both Lines
Lines1(1).XData=XLim1; % Unnecessary but I'll leave it there for clarity
Lines1(1).YData=[cursorPoint1(1,2) cursorPoint1(1,2)];
Lines1(2).XData=[cursorPoint1(1,1) cursorPoint1(1,1)];
Lines1(2).YData=YLim1; % Unnecessary but I'll leave it there for clarity
Lines2(1).XData=XLim2; % Unnecessary but I'll leave it there for clarity
Lines2(1).YData=[cursorPoint1(1,2) cursorPoint1(1,2)];
Lines2(2).XData=[cursorPoint1(1,1) cursorPoint1(1,1)];
Lines2(2).YData=YLim2; % Unnecessary but I'll leave it there for clarity
end
elseif (cursorPoint2(1)<XLim2(2) && cursorPoint2(2)<YLim2(2) && cursorPoint2(1)>=XLim2(1) && cursorPoint2(1)>=YLim2(1))
Lines1=findobj('Type','line','Parent',handles.axes2);
Lines2=findobj('Type','line','Parent',handles.axes3);
if isempty(Lines2)
% If Lines is empty, we need to create the line objects
line(XLim1,[cursorPoint2(1,2) cursorPoint2(1,2)],'Color','g','Parent',handles.axes2);
line([cursorPoint2(1,1) cursorPoint2(1,1)],YLim1,'Color','g','Parent',handles.axes2);
line(XLim2,[cursorPoint2(1,2) cursorPoint2(1,2)],'Color','g','Parent',handles.axes3);
line([cursorPoint2(1,1) cursorPoint2(1,1)],YLim2,'Color','g','Parent',handles.axes3);
else
% If not, we just update the fields XData and YData of both Lines
Lines1(1).XData=XLim1; % Unnecessary but I'll leave it there for clarity
Lines1(1).YData=[cursorPoint2(1,2) cursorPoint2(1,2)];
Lines1(2).XData=[cursorPoint2(1,1) cursorPoint2(1,1)];
Lines1(2).YData=YLim1; % Unnecessary but I'll leave it there for clarity
Lines2(1).XData=XLim2; % Unnecessary but I'll leave it there for clarity
Lines2(1).YData=[cursorPoint2(1,2) cursorPoint2(1,2)];
Lines2(2).XData=[cursorPoint2(1,1) cursorPoint2(1,1)];
Lines2(2).YData=YLim2; % Unnecessary but I'll leave it there for clarity
end
end