how to find center of mass in each grid based on foreground pixel

this is my code

clc;
clear all;
close all;
a = imread('i2eee.jpg');
figure;imshow(a);

% Normalizatoin

b = imresize(a,[100,100]);
figure;imshow(b);

% Binarization
th = graythresh(b);
figure;imshow(th);

a = im2bw(b,th);
figure,imshow(a);
s=0;
x=1;z=1;
w = 10;
h = 10;
c=100/w;
r=100/h;
a(r:c:end,:,:) = 0;
a(:,r:c:end,:) = 0;
figure,imshow(a);

cellA = cell(r,c);
m=1;
n=1;
Row_CoM=0;
Col_CoM=0;
tot=0;
ic=1;

for i=1:w:100
for j=1:h:100            
k=i+w-1;
l=j+h-1;
i1=1;j1=1;
if(k <=100 && l<=100)
for ii=i:k
for jj=j:l
s(i1,j1)=a(ii,jj);
j1=j1+1;
end
i1=i1+1;
j1=1;
end
cellA{ic}=s;
ic=ic+1;            
end       
end
end
rr=0;
cc=0;
for i=1:10
for j=1:10
s=cellA{i,j};
Row_CoM = 0;
Col_CoM = 0;
for rw=1:10
for cr=1:10
if(s(rw,cr)==0) 
Row_CoM = Row_CoM + rw;
Col_CoM = Col_CoM + cr;
tot=tot+1;
end
end
end            
Row_CoM = Row_CoM/tot;
Col_CoM = Col_CoM/tot;
rr=rr+Row_CoM;
cc=cc+Col_CoM;
j = impoint(gca,[rr,cc]);
end  
end