Crop image from an axes used in a GUI

listBoxStrings = get(handles.listbox1,'String');
ListBoxValue = get(handles.listbox1,'Value');
if(find(strcmp(listBoxStrings,'Afghanistan')) == ListBoxValue)
set(handles.text3,'String','Processing image for Afghanistan, please wait!');
Rect = imrect(gca,[50 20 50 50]);
setColor(Rect,'green')
setFixedAspectRatioMode(Rect,1);
fcn = makeConstrainToRectFcn('imrect',get(gca,'XLim'),get(gca,'YLim'));
setPositionConstraintFcn(Rect,fcn); 
pos = getPosition(Rect); 
I2 = imcrop(handles.axes1,pos);
imshow(handles.axes1,I2);

This code is linked to a button, when I push the button it gives me the square white crop on top of the image. I get an error though:

I can't crop the image, due to this error. The image is a JPEG

Thanks.

Answer 1

[JR]

listBoxStrings = get(handles.listbox1,'String');
ListBoxValue = get(handles.listbox1,'Value');
if(find(strcmp(listBoxStrings,'Afghanistan')) == ListBoxValue)
set(handles.text3,'String','Processing image for Afghanistan, please wait!');
Rect = imrect(gca,[50 20 50 50]);
setColor(Rect,'green')
setFixedAspectRatioMode(Rect,1);
fcn = makeConstrainToRectFcn('imrect',get(gca,'XLim'),get(gca,'YLim'));
setPositionConstraintFcn(Rect,fcn); 
pos = getPosition(Rect);
Crop = imcrop();
imshow(Crop, 'Parent', handles.axes1);
guidata(hObject, handles);
axis(handles.axes1, 'image')

This code works and I can now crop, but I am using my own free hand crop rectangle. How would I be able to still crop, but using the box I have already made?