I want to get the image I got in a function in another function

this is the function I used to get the image

function selectImage_Callback(hObject, eventdata, handles)
[filename, pathname] = uigetfile({'*.jpg';'*.bmp';'*.png''*.jpeg'},'File Selector');
 handles.myImage = strcat(pathname, filename);
 axes(handles.imageAxes2);
 imshow(handles.myImage)
 % save the updated handles object
 clear axes scale
 axis off
 guidata(hObject,handles);

and I'm trying to use the same image in another function

function classifyImage_Callback(hObject, eventdata, handles)
          net = alexnet;
          image = handles.myImage;
          image = imresize(image,[227 227]);
          label = classify(net,image);
          set(handles.imageType, 'String' , label)

%

[kamrul islam sharek]

I = imread('grey.jpg');

Points = detectSURFFeatures(I );

imshow(I);

hold on;

plot(Points.selectStrongest(10));

problem isError using

detectSURFFeatures>checkImage (line 128)

Input image must be a 2-D grayscale

image. You can use RGB2GRAY to convert

your image to a 2-D grayscale image.

Error in detectSURFFeatures (line 81)

checkImage(I);

Error in Object (line 2)

Points = detectSURFFeatures(I);

>> Object

Error: File: Object.m Line: 2 Column: 31

Invalid expression. Check for missing

multiplication operator, missing or

unbalanced delimiters, or other syntax

error. To construct matrices, use

brackets instead of parentheses.

[Image Analyst]

Did you use rgb2gray() like it told you to? If not, why not?

rgbImage = imread('grey.jpg');
if ndims(rgbImage) > 1
    % Need to convert to gray scale.
    grayImage = rgb2gray(rgbImage);
else
    grayImage = rgbImage; % It's already gray scale.
end
Points = detectSURFFeatures(grayImage);

Answer 1

[Alfonso]

Try using the user data to save/load variables in different functions:

function selectImage_Callback(hObject, eventdata, handles)
[filename, pathname] = uigetfile({'*.jpg';'*.bmp';'*.png''*.jpeg'},'File Selector');
fullFileName = fullfile(pathname, filename);
handles.myImage = imread(fullFileName); % attending to the 2nd answer of post
axes(handles.imageAxes2);
imshow(handles.myImage)

% Save in user data
img = handles.myImage;
data_image= struct('img',img);
hObject.UserData = data_image;

% save the updated handles object
clear axes scale
axis off
guidata(hObject,handles);

Then in the second function, you load the user data of the first function

function classifyImage_Callback(hObject, eventdata, handles)
          % Load the user data of the 1st function
          h = findobj('Tag','selectImage');
          data_image = h.UserData;

          net = alexnet;
          image = data_image.img;
          image = imresize(image,[227 227]);
          label = classify(net,image);
          set(handles.imageType, 'String' , label)

In the second function in the findobj you should put the tag of your gui component, I wrote selectImage as it seems this is it.

[Mohamed Amine Habch]

thanks for you answer Alfonso, now I got this error when trying to get the image from data_image

Dot indexing is not supported for variables of this type.
Error in ClassifyV2>classifyImage_Callback (line 71)
    image = data_image.img;

[Stephen23]

Why bother introducing the complexity of findobj, when handles is already available with the required data in it?

[Mohamed Amine Habch]

How can I get the image from handles in the 2nd function? I'm a still a newbie in Matlab programming

[Stephen23]

@Mohamed Amine Habch: exactly the way you did in your question:

handles.myImage

Note that you should avoid using the variable name image, as this shadows the inbuilt image function.

[Mohamed Amine Habch]

thanks a lot it worked!

[Alfonso]

About the error of trying to get the image of data_image, I wrote the tag of the second function in findobj where I should have written the tag of the 1st function; now it is corrected.

Glad you could finally solve the error.

[Mohamed Amine Habch]

yeah I figured you meant the first function, but I already tried it but didn't work, anyways the other parts of your solution really helped =) thank you!

Answer 2

[Image Analyst]

This is wrong:

handles.myImage = strcat(pathname, filename);

You're just storing the filename string, not the actual image.

What you need to do is to call imread() with that filename string to get the actual image:

fullFileName = fullfile(pathname, filename);
handles.myImage = imread(fullFileName);

[Mohamed Amine Habch]

thank you!