MATLAB: Changing Sensitivity of ‘Imbinarize’ using a slider

digital image processingimbinarizeslider

Hey guys,
I´m binarizing Images using Matlab and try to figure out the right sensitivity value for each image. Therefore a slider would be quite useful.
How could this be done?
Here is my code so far.
clf()
I= imread('Bild_1.jpg');    %input
I=I(:,:,1);                 %Selecting a colour
I = imbinarize(I,'adaptive','ForegroundPolarity','dark','Sensitivity',sens); %turn grayscale image in binary image
                                                                    %sens is my variable 
imshow(I);
fig = uifigure();
fig.Position([3,4]) = [400,75];
sld = uislider(fig,'Position',[50,50,300,50],'Value',1,'Limits',[0,1],...
    'ValueChangedFcn', @(sld,event)changeSensitivityFcn(sld,event));
function changeSensitivityFcn(sld, event)
sens=sld.Value
drawnow()
end
I hope you can help me.
Greetings
Here is a related question i asked about the sliders
https://de.mathworks.com/matlabcentral/answers/471732-control-image-transparency-with-a-slider-appdesigner#answer_383287

Best Answer

You can store the figure handle in a variable using uiaxes which can be passed to the changeSensitivity function to modify the binarization according to the changed sensitivity factor.
You can modify your code to something similar to as the following:
clc; clear; close all;
I= imread('peppers.png');    %input
I = I(:,:,1);                 %Selecting a colour
fig = uifigure;
cg = uiaxes(fig, 'Position', [50, 70, 500, 300]);
imshow(I, 'parent', cg);
sld = uislider(fig, 'Position', [100 50 300 50], 'Value', 1, 'Limits', [0,1],...
'ValueChangedFcn', @(sld, event)changeSensitivityFcn(event, cg, I));
function changeSensitivityFcn(event, cg, I)
    sens = event.Value;
    cg.Children.CData = im2uint8(imbinarize(I, 'adaptive', 'ForegroundPolarity', 'dark', ...
        'Sensitivity', sens)); 
    drawnow();
end
Hope this helps!
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