Errors using imwrite "Unable to determine the file format from the filename" I am trying to splice together the name of a new image file but dont understand why imwrite isnt working.

% --- Executes on button press in Save.
function Save_Callback(hObject, eventdata, handles)
% hObject    handle to Save (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global y
newname = get(handles.newname,'String')
display(y);
tif = '.tif';
filename = [newname tif];
display(filename);

imwrite(y,'default',newname,'tif')

Heres hat I have so far. Not really sure how to solve this issue with the way I am going about it. I though thtat if the filename had the .tif written in it it may recognize the fileformat, but I guess not. Any suggestions? Also on another note, how can I create somesort of dropdown menu to specify the pathway for this image file? Thanks

[Stephen23]

This time I fixed your code formatting for you. In future please do it yourself by first selecting your code text, and then clicking the {} Code button. The default text that clicking the button produces is not markup.

Answer 1

[Stephen23]

You could try reading the imwrite documentation. At the top of the page there is a list of the accepted syntaxes:

Syntax

imwrite(A,filename)example
imwrite(A,map,filename)example
imwrite(___,fmt)
imwrite(___,Name,Value)

Whereas what you are trying to use is:

imwrite(y,'default',newname,'tif')

What does 'default' mean? It does not seem to fit any of the permitted syntaxes. Where did you get this from? I don't see 'default' listed as any of the permitted input arguments. When I try your code with an image it produces the same error:

>> X = imread('parula_0.png');
>> newname = 'test';
>> imwrite(X,'default',newname,'tif')
??? Error using ==> imwrite at 435
Unable to determine the file format from the filename.

but when I remove 'default' from your code it works fine:

>> imwrite(X,newname,'tif')

with a new file created correctly. This is why reading the documentation is useful.

Also note that your code creates a new name string in the variable filename, but that you do not use this variable. Perhaps you really meant to call this:

imwrite(y,filename,'tif')