what is the function of these code?

anyone can tell me what this run button do?

% --- Executes on button press in Run_btn.
function Run_btn_Callback(hObject, ~, handles)
% hObject    handle to Run_btn (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
cd(handles.current_folder);
files=dir('*.TIF');
fid = fopen(strcat(handles.current_folder,'\eggResult.txt'),'wt+');
fprintf(fid, '\tFiles_Name\t\t          Regression(r)       Slope(m)\tOffset(b)\t      Result\n\n');
fclose(fid);

maxconbar=waitbar(0,'1','Name','Processing Imgaes',...
            'CreateCancelBtn',...
            'setappdata(gcbf,''canceling'',1)');

a = 1;
for i=1: length(files)

       if getappdata(maxconbar,'canceling')
                  break
       end

       b = length(files);
       %Report file being process in waitbar message field
       waitbar(i/length(files),maxconbar,sprintf(strcat( num2str(a) ,'/', num2str(b) ,'   Processing:',char(files(i).name))));
       a = a + 1;
  %    disp(strcat('Processing ',char(files(i).name)));

      im0=imread(files(i).name);
      im0=imadjust(im0,stretchlim(im0),[]);
      s=size(im0);
      im0=imcrop(im0,[floor(s(1)/4) floor(s(2)/4) floor(s(1)/2) floor(s(2)/2)]);
  %figure,imshow(im0);
      im1=im2bw(im0,graythresh(im0));
  %figure,imshow(im1);
      im1=imcomplement(im1);
  %figure,imshow(im1);
      im1=imfill(im1,'holes');
  %figure,imshow(im1);
      s=size(im1);
      onepercent=floor(s(1)*s(2)*0.01);
      im1=bwareaopen(im1,onepercent);
  %figure,imshow(im1);
      imcc=bwconncomp(im1);
      %----------------------------------------------
      Zebrafishdata = regionprops(imcc, 'area');
      Zebrafish_areas = [Zebrafishdata.Area];
      [max_area, idx] = max(Zebrafish_areas);
      percentage=floor(s(1)*s(2)*0.16);
      if max_area>=percentage
          continue;
      else
          Zebrafish = false(size(im1));
          Zebrafish(imcc.PixelIdxList{idx}) = true;
          area{i}= max_area;

          greyvector=im0(imcc.PixelIdxList{1});
          greyvector=sort(greyvector);
  %figure,plot(greyvector,'color','r')

          y=double(greyvector);
          y=y';
          L=length(y);
          t=1:L;
          [r,m,b]=regression(t,y);
         %[files_name]=files(i).name;

          fid  = fopen(strcat(handles.current_folder,'\eggResult.txt'),'at+');
          string1='alive';
          string2='dead';
          if m>=0.2250
              fprintf(fid, '%s     %7.5f            %6.4f       %e          %s\n\n',files(i).name,r,m,b,string1);
          else
              fprintf(fid, '%s     %7.5f            %6.4f       %e          %s\n\n',files(i).name,r,m,b,string2);
          end

              fclose(fid);

         if m<0.2250
              save{i}= m;
              D=cell2mat(save);
  %             q=plot(handles.axes2,D);           
  %             set(q,'Color','red')
  %             hold all;

          else
              store{i}= m;
              A=cell2mat(store);
  %             p=plot(handles.axes2,A);
  %             set(p,'Color','blue')
  %             title('Alive(Blue) vs Dead(Red)');

          end       
  %figure,plotregression(t,y)

      end
  end
  delete(maxconbar); 
  q=plot(handles.axes2,D);           
  set(q,'Color','red')
  hold all;

p=plot(handles.axes2,A);
set(p,'Color','blue')

set(handles.axes2,'XGrid','on');
set(handles.axes2,'YGrid','on');
title('Alive(Blue) vs Dead(Red)');

message = sprintf('%d images processed.', a-1);  
uiwait(msgbox(message));

guidata(hObject, handles);

Answer 1

[Image Analyst]

Looks like it crops an image of zebra fish, then thresholds and does some particle size analysis. It then does some sort of regression on all the pixel locations of the biggest blobs and gets something called m (I don't have the regression() function so I don't know what that is), and decides if the fish is alive or dead based on if m is greater or less than 0.2250.