deadspace in UIaxes near image

Trying to create a clean looking GUI

Inserting image into UIaxes

there seems to always be dead space around the image that i dont understand (Shown below)

Trying to read the image size to resize UI axes but getting extra space on both sides.

Can someone check this ?

There seems to be 2 properteis UI figure and UI axes, am I using the right one (both in forms initilization)?

        % Button pushed function: LoadImageFileButton
        function openfile(app, event)
              [file,path]=uigetfile({'*.jpg';'*.bmp';'*.gif';'*.tiff'}, 'Select file');
              app.a= double(imread(file));
              app.a= -(0.0316*app.a) +8.3;  
              app.b = app.a;
              %app.UIAxes.Positon = [ 100 , 100  , size(app.a,1),  size(app.a,2)] 
               app.UIAxes.Position = [400 100 size(app.a,1)/10 size(app.a,2)/10];
           %    app.UIFigure.Position = [100 100 size(app.a,1)/3 size(app.a,2)/3];
              imagesc(app.a,'Parent',app.UIAxes); 
              colorbarupdate(app, event);
        end

Answer 1

[ScottB]

You could try "axis tight".

[Voss]

% ...
imagesc(app.a,'Parent',app.UIAxes);
axis(app.UIAxes,'tight')
% ...

[JM]

yes

this works

dont even need this part

% app.UIAxes.Position = [400 100 size(app.a,1)/10 size(app.a,2)/10];

[JM]

there is typically a button about "solution accepted" howeever, it is not there for this thread

[Voss]

That's because these are comments, not answers.

I'll make ScottB's comment an answer and then you can accept it.