i want the explanation of below code

sz=size(sondos,2);
 DC=[]; QZ=4;
for a=1:sz
 FDCT=dct2(sondos(a).block);
 FDCT=round(FDCT./QZ);
  DC(a,1)=FDCT(1,1);
end

[nndata km]=size(DC);
G=[];
numclass=4;
[centers,mincenter,mindist,q2,quality] = FastKmean(DC,numclass,km);
for n=1:numclass
    ind= find(mincenter==n);
    for i=1:length(ind)
        
        G(n,i)= ind(i);
        
    end
end

[Rik]

Have a read here. It will greatly improve your chances of getting an answer. This time I edited your question for you. Next time, please use the tools explained on this page to make your question more readable.

As I mentioned in the previous thread: code commenting is important. Where did you get this from? Why don't you ask the original author? Also, have you tried a basic Matlab tutorial to get you started? Nobody is born understanding Matlab, and courses like OnRamp are really helpful.

[Image Analyst]

No idea. Looks like it's doing something with compression and k-means, but other than that I don't know. You should ask the author.

[kotha umeshchandra]

k -means for what?