How to update the slider when I need to show different series of images (MATLAB GUI, not programmed)

Hello. I have a problem when using the slider to update my images. I have a series of images. I first use the slider to update the images. It works. After some crop of the first series of images, I got another series of images. I wonder When I change my images to the series 2. How to update the slider. Because when I push the slider, it still update the first series images. Thank you.

[Geoff Hayes]

Pan - how are you managing the second series of images? Are they saved to the computer or are you saving them to the handles structure (I'm assuming that you are using GUIDE)? I suspect that your slider callback function is hard-coded to reference only the first series of images. Can you post the code for this callback?

[Image Analyst]

And show a screenshot. I don't even have any idea if you're just dispalying one image at a time, or the whole series simultaneously. And what does "update" mean? Does it mean you just display one of the images, or does it mean that you use the slider value to apply some mathematical operation on the image data?

[Penny]

Thanks to Geoff, here is my code, where 'Img' is the first series of the images data. Next, I got the second series of the images. The 3 Matrix data was 'Img_2', and I saved the second series images data into the handles structure. The problem is how to use the 'Img_2' in the slider call back. Because I got the 'Img_2' after I callbcak the slider for the first time.

if true
function slider2_Callback(hObject, eventdata, handles)
% hObject    handle to slider2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
Img=handles.Img;
SIZE_Z=handles.SIZE_Z;
set(hObject,'Min',1,'Max',SIZE_Z);
set(hObject,'SliderStep',[1/(SIZE_Z-1),1/(SIZE_Z-1)]);
slider2Val=floor(get(hObject,'Value'));
currentSlice=slider2Val;
imshow(Img(:,:,currentSlice),[752 1512],'Parent',handles.axes6); 
handles.currentSlice=currentSlice;
guidata(hObject,handles);
edit12_Callback(hObject, eventdata, handles);
end

Answer 1

[Geoff Hayes]

Pan - since your slider2_Callback uses the images from handles.Img, then either you will need to replace them with the Img_2 set of images or use a different field within handles to manage the images to be used by this callback. For example, when you initialize handles.Img, then also initialize another field as

 handles.sliderImages = handles.Img;

Then your slider callback would do

 function slider2_Callback(hObject, eventdata, handles)
 Img = handles.sliderImages;
 % etc.

And when you initialize handles.Img_2, then you would replace the sliderImages too

 handles.sliderImages = handles.Img;

Note that each time you update these images for the slider, you would then update the Min, Max, and SliderStep

 set(handles.slider2,'Min',1,'Max',SIZE_Z);
 set(handles.slider2,'SliderStep',[1/(SIZE_Z-1),1/(SIZE_Z-1)]);

(rather than updating these values within the callback) where SIZE_Z is the number of images in sliderImages.

[Penny]

Hi, Geoff, thanks to your annswer. It works by using handles.sliderImages = handles.Img; But another problmes appears. When I update the Min, Max and SliderStep, it said that'Warning: 'slider' control cannot have a 'Value' outside of 'Min'-'Max' range Control will not be rendered until all of its parameter values are valid '.I know this is because the current Slider Value is bigger than the Max value I updated. So can you tell me how to reset the current slider value as 1 to make it work. Thanks

[Geoff Hayes]

Pan - perhaps try

 set(handles.slider2,'Value',1);

[Penny]

HI, Geoff, thank you very much. I got it. I solved the problem, thanks again.