Skin Color Block in Matlab

%%%%%%%%%%%%%%% FIND SKIN COLOR BLOCKS %%%%

[L,lenRegions] = bwlabel(SN_fill,4);
AllDat  = regionprops(L,'BoundingBox','FilledArea');
AreaDat = cat(1, AllDat.FilledArea);
[maxArea, maxAreaInd] = max(AreaDat);

FaceDat = AllDat(maxAreaInd);
FaceBB = [FaceDat.BoundingBox(1),FaceDat.BoundingBox(2),...
    FaceDat.BoundingBox(3)-1,FaceDat.BoundingBox(4)-1];

aa=imcrop(rgb2gray(uint8(I)).*uint8(SN_fill),FaceBB);

%  figure,imshow(aa);
%  title('Identified Face');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%