How to create an undo button for image colorization?

I'm currently doing an image colorization application in GUI and I'm facing trouble in creating an undo button to undo the colours.

Can anyone help me with this?

Below is my code that might be useful for solving my problem.

Thank you.

function Result = Paint(InputImage,C)

Color(:,:,1)=C(1,1);
Color(:,:,2)=C(1,2);
Color(:,:,3)=C(1,3);
Color=uint8(Color);

Result=InputImage;
Level=graythresh(InputImage);
Img=im2bw(InputImage,Level);

[L,~]=bwlabel(Img);

[X,Y]=ginput(1);
Num=L(ceil(Y),ceil(X));

[R,C]=find(L==Num);
Tmp=[R,C];
for k=1:size(Tmp,1)
    Result(Tmp(k,1),Tmp(k,2),1)=Color(:,:,1);
    Result(Tmp(k,1),Tmp(k,2),2)=Color(:,:,2);
    Result(Tmp(k,1),Tmp(k,2),3)=Color(:,:,3);
end

end

Answer 1

[Jan]

An "Undo" button does not depend in any way from the applied computations. All you have to do is to store the formerly existing data in the GUI and restore it on demand. Now it matters, how you have created your GUI: With AppDesigner, GUIDE or programmatically? In all cases, create the wanted button and create a backup of the current values e.g. in the ApplicationData or UserData of the figure, before you call the function to modify the data.

See also this professional method: https://undocumentedmatlab.com/blog/customizing-uiundo