imread figures from new folder created

I created figures in the folder. then, I want to read figures again to calculate, and then save .xls file in the folder created. how to do this? this is my code, but it is not working:

for ii=0:10:360
     for jj=0:10:90
view(ii,jj);
%%%create a multiple folder
     newdir=sprintf('view%2dview%2d',ii,jj);
       mkdir(fullfile(newdir));
%rotate masks
     for i=1:36
       rotate(aa,[0,0,1],1);
% print figure with rotate
 filename = sprintf('Slice_%d.png', i);
  print('-dpng', fullfile(newdir, filename));
pause(2);
end
%%%%%%%%calculate red pixels and save in excel file
%%%%%%%%%%%%%%%
for i = 1 : 36
filename=['D:\Matlab code RMC\zzzz\newdir\Slice_ ' num2str(i,'%01d') ];
      rgbImage = imread(filename);
      imshow(rgbImage);
             redChannel = rgbImage(:,:, 1);
             greenChannel = rgbImage(:,:, 2);
             blueChannel = rgbImage(:,:, 3);
             greenness = mean2(greenChannel);
% Extract the individual red, green, and blue color channels.
redPixels = redChannel == 255 & greenChannel == 0 & blueChannel == 0;
redArea(i) = sum(redPixels(:));
end
%I want to save .xls into the folder created view(ii)view(jj)
filename='test.xlsx';
A=[redArea];
xlswrite(filename,A);