How can i read images for filtering using if else condition in GUI?

function popupmenu3_Callback(hObject, eventdata, handles)

 popupimage=get(popupmenu3.handles,'value');

img=imread('flower.jpg');
img1=imread('balloon.jpg');

%average

 if
 popupimage==img

    e=fspecial('average',[33])
    A=imfilter(img,e);
    axes(handles.axes2);
    imshow(A);

 else if popupimage==img1

   e=fspecial('average',[33])        
   B=imfilter(img1,e);        
   axes(handles.axes2);     
   imshow(B);

 end

Answer 1

[Image Analyst]

Try this:

selectedItem = get(popupmenu3.handles,'value');

img=imread('flower.jpg');
img1=imread('balloon.jpg');

%average
e=fspecial('average',[33])
axes(handles.axes2);
if selectedItem == 1
  A=imfilter(img,e);
  imshow(A);
elseif selectedItem == 2
  B=imfilter(img1,e);
  imshow(B);
end

[siti]

thanks for your answer.i can read the image but,why i still cannot filter the image?

[Image Analyst]

You have to give me more information, because when I selected an item number, and used standard MATLAB demo images, it worked just fine:

selectedItem = 2; % get(popupmenu3.handles,'value');

img=imread('onion.png');
img1=imread('cameraman.tif');

%average
e=fspecial('average',[33])
% axes(handles.axes2);
if selectedItem==1
  A=imfilter(img,e);
  imshow(A);
elseif selectedItem==2
  B=imfilter(img1,e);
  imshow(B);
end

Does the code above work for you? If so, investigate why your is different.

[Image Analyst]

Siti's "Answer" moved here:

thanks again,now i can do the filtering process..but sometimes the output showing the different image. Actually what i'm trying to do is to read the images from files

function Graybutton_Callback(hObject, eventdata, handles)
path='G:\IP.projek\grayImg';
filter='*.jpg';
selectedFile=uigetfile(fullfile(path, filter));
axes(handles.axes1);
imshow(selectedFile);

function ColorButton_Callback(hObject, eventdata, handles)
path='G:\IP.projek\color img';
filter='*.jpg';
selectedFile=uigetfile(fullfile(path, filter));
axes(handles.axes1);
imshow(selectedFile);

and then i choose flower image in color img folder for example,then i want to apply filtering process.Currently i'm using popup menu for the list of filters .So now i'm just a little bit confuse.does i need to use switch case for every filter that i'm going to use? And in every case should i put if else condition for different images that i'm going to filter?.if yes,how to do it? i'm sorry for asking this but i really don't know.

[Image Analyst]

No. You should have a listbox that you load up with image names. Then you can have a listbox or popup that you load up with filter names. In the callback of each control, you should call a function called FilterSelectedImage(handles) that you write. Inside FilterSelectedImage() you get the string and value of the listbox, then read in the selected image into a variable in that function. Then you get the value of the filter listbox or popup. You have a switch or if to filter the image according to the different filter types, then display it of course. This way no matter which you click on - the image file name, or the filter name - you will read in an original image and perform the filter on it.

[siti]

i try to use listbox to load the image.but i got error..whats wrong with my code?

 function listboxImg_Callback(hObject, eventdata, handles)
 img = get(handles.listboxImg, 'Value');
 if(img==1)
    A=imread('flower.jpg');
    axes(handles.axes1);
    imshow(A);
 elseif(img==2)
    B=imread('balloon.jpg');
    axes(handles.axes1);
    imshow(B);
 elseif(img==3)
    C=imread('Grayflower.jpg');
    axes(handles.axes1);
    imshow(C);
 elseif(img==4)
    D=imread('Grayballoon.jpg');
    axes(handles.axes1);
    imshow(D);
 end

[Image Analyst]

You don't need any of that. In your callback, just have this:

% Get selected index.
selectedItem = get(handles.listboxImg, 'Value');
% If more than one is selected, bail out.
if length(selectedItem) > 1
  return;
end
% If only one is selected, display it.
% First you need to get a list of all the items in the listbox.
ListOfImageNames = get(handles.lstImageList, 'string');
% Now construct the filename.
baseImageFileName = cell2mat(ListOfImageNames(selectedItem));
fullImageFileName = [handles.imageFolder '\' baseImageFileName];  % Prepend folder.
% Now read in the image.
rgbImage = imread(fullImageFileName);
% Now display the image.
axes(handles.axes1);
imshow(rgbImage);
title(baseImageFileName, 'FontSize', 20);

[Image Analyst]

siti's "Answer" moved here since it contains another question and appears not to be a final answer to the original question, but a reply to me.

Thanks,i already use this coding.

 function LoadImg_Callback(hObject, eventdata, handles)
 % hObject    handle to LoadImg (see GCBO)
 % eventdata  reserved - to be defined in a future version of MATLAB
 % handles    structure with handles and user data (see GUIDATA)
  contents = get (handles.listbox1,'Value');

 switch contents

    case 1
         A=imread('flower.jpg');
         axes(handles.axes1);
         imshow(A);
    case 2
         A=imread('balloon.jpg');
         axes(handles.axes1);
         imshow(A);

    case 3
         A=imread('Grayflower.jpg');
         axes(handles.axes1);
         imshow(A);

    case 4
         A=imread('Grayballoon.jpg');
         axes(handles.axes1);
         imshow(A);

 end

And i wanna ask.how can i get images from listbox to be filter in popup menu?i dont know how to write the code so that all the images in listbox can be used to filter in popup menu.

[Image Analyst]

It looks like you ignored my recommendations and went ahead with your prior code. Not sure why you didn't like my code.

Anyway, what do you have? A listbox with image names, and a popup with filter names, or what? Please attach your m and fig files or a screenshot. Do you want the user to click on an image name in the listbox and a filter showing in the popup will automatically be applied and the resulting image displayed in the axes?

[siti]

i'm sorry.it is not that i don't like your code.i'm try to figure out my coding,and i got it before you reply that comment.

yes.i have image names in listbox and filter names in popup.so when user click average filter for example,it will apply to any images that user choose in listbox.

[Image Analyst]

First try this. Have the callbacks of both the listbox and the popup call the same function called DisplayAndFilterImage. Nothing else, just simple a line like this:

DisplayAndFilterImage(handles)

Now define that function like this:

function DisplayAndFilterImage(handles)
% Get selected listbox index.
selectedItem = get(handles.listboxImg, 'Value');
% If more than one is selected, bail out.
if length(selectedItem) > 1
  return;
end
% If only one is selected, display it.
% First you need to get a list of all the items in the listbox.
ListOfImageNames = get(handles.lstImageList, 'string');
% Now construct the filename.
baseImageFileName = cell2mat(ListOfImageNames(selectedItem));
fullImageFileName = [handles.imageFolder '\' baseImageFileName];  % Prepend folder.
% Now read in the image.
rgbImage = imread(fullImageFileName);
% Now display the image in axes1.
axes(handles.axes1);
imshow(rgbImage);
title(baseImageFileName, 'FontSize', 20);

% Now get what filter they chose.
selectedPopupIndex = get(handles.popup1, 'Value');
axes(handles.axes2); % We'll show result in axes 2.
switch selectedPopupIndex 
    case 1
        % Median filter, or whatever.
        filteredImage = medfilt2(rgbImage);
        imshow(filteredImage);
    case 2
        % Your own custom filter, or whatever.
        filteredImage = MyFilter(rgbImage);
        imshow(filteredImage);
end

[siti]

 fullImageFileName = [handles.imageFolder '\' baseImageFileName];

for this coding,imageFolder is a folder that i created for my images right?

and then

 function DisplayAndFilterImage(handles)

where should i put it?is it in both listbox and popup callback?

[Image Analyst]

That looks like old code. Now I use code like this:

fullImageFileName = fullfile(handles.imageFolder, baseImageFileName);

Yes, handles.imageFolder is whatever folder you have your images in.

You put DisplayAndFilterImage() elsewhere in your file, like down at the bottom, as the last function.

[siti]

why i got this error 'Reference to non-existent field 'images'. ' ? when i use this :

baseImageFileName = cell2mat(ListOfImageNames(selectedItem));

fullImageFileName = fullfile(handles.images, baseImageFileName);

whats wrong with my code?

[Image Analyst]

You need to give it the folder with your images in it. If you didn't store the image folder string attached to your handles structure, then where are you storing it?

[siti]

i already store my images in the folder..but why it gives me this 'Reference to non-existent field 'images'. 'error?

[Image Analyst]

What variable name contains the string that is the folder name?