i need explaination for this code .....thanks in advance

if true
  % code
end
  compt=0; 
  T_edge=[0.1 0.2];
  threshold=15;

[FileName,PathName] = uigetfile('*.*','Select the image file');
nomfich=[PathName,FileName];
 % Read the sample image in
 imo=imread(nomfich);

imo = imresize(imo, [300 300]);
SI=size(imo);
im=rgb2gray(imo);%figure(11); imshow(im);
h=figure(1); imshow(imo);set(h,'name',nomfich);

 edgeim = edge(im,'canny', T_edge, 1);
 figure, imshow(edgeim);

 [edgelist, labelededgeim] = edgelink(edgeim, 10);
 h = waitbar(0,'Please wait...Analysis can be time consuming for High Resolution image');  
    Nmax=max(max(labelededgeim));

 SC=zeros(1000,2,100);
    for uu=1:Nmax
        waitbar(uu/Nmax,h)
        [r,c] = find(labelededgeim==uu);  
        rc = [r c];
        [sx sy]=size(rc);
        [imx,imy]=size(labelededgeim);

        n1=zeros(imx,imy); 
        for i=1:sx
            x1=rc(i,1);
            y1=rc(i,2);
            n1(x1,y1)=255;
        end % Storing the extracted image in an array

 Cn1=ait_imneg(n1);
 [y,x]=find(Cn1==0);

 cerne=[y,x];

 delta_sq = diff(cerne).^2;
 perimeter = sum(sqrt(sum(delta_sq,2)));
 P(uu)=perimeter/length(cerne);
  if P(uu) > threshold
    Pu(uu)=uu;
    compt=compt+1;
    disp('THE AGE OF THE WOOD IS ');
    disp(compt);
    SC(1:length(cerne),:,compt)=cerne;
    disp('good');
    %perimeter/length(cerne)
 metric_string = [sprintf('R %d ', compt)];%,sprintf('\n'), sprintf('P %d', P(uu))];
 figure(1);hold on;plot(x,y,'g.');hold on;
 text(mean(x)-5,min(y)+5,metric_string,'Color','y',...
       'FontSize',11,'FontWeight','bold');

    else
    disp('NOT A RING');
    end 
    end
  disp(sprintf('age of the wood is %d',compt));
 close(h);

[Guillaume]

I doubt anyone is going to bother explaining every single line of code.

Why don't you tell use which line is confusing you?

[John D'Errico]

No problem. It tries to compute the age of some wood. Looks pretty old to me.

If you want more than that, start learning MATLAB. Or, ask a SPECIFIC question about one line. Or contact the author.

[Guillaume]

Note that the whole

        [r,c] = find(labelededgeim==uu);  
        rc = [r c];
        [sx sy]=size(rc);
        [imx,imy]=size(labelededgeim);

        n1=zeros(imx,imy); 
        for i=1:sx
            x1=rc(i,1);
            y1=rc(i,2);
            n1(x1,y1)=255;
        end % Storing the extracted image in an array

could be replaced by just one line:

n1 = 255 * (labelededgeim == uu);

which will be a lot faster as well.

[y,x]=find(Cn1==0);
cerne=[y,x];
delta_sq = diff(cerne).^2;
perimeter = sum(sqrt(sum(delta_sq,2)));

I am very skeptical that this calculates a perimeter correctly.

Answer 1

[bidyut mandi]

Here a color image file is selected and then converted to gray image.After that edge of the image is shown(For more info about edge detection https://in.mathworks.com/help/images/edge-detection.html).Then Nmax is calculated by taking the max of labelededge.Then two loop function used.First loop for [r,c], [sx sy] and [imx,imy] .Second loop for x1, y1, and n1(x1,y1).After that P(uu) is calculate and a loop is use for showing if P(uu)>threshold then dispay 'the age of the wood is' else display 'not a ring'. Hope this explaination will help.