function J=zoomcolor(I,d);
close all;

I1=I(:,:,1);I2=I(:,:,2);I3=I(:,:,3);
 J1=samplingzoom(I1,d);[n,m]=size(J1);
 J2=samplingzoom(I2,d);
 J3=samplingzoom(I3,d);
 J(:,:,1)=J1; J(:,:,2)=J2; J(:,:,3)=J3;
  figure;imshow(J);

  function Irec = samplingzoom(I,d);

close all;
I=double(I)./255;
s=size(I);
m=s(1);n=s(2);
n=min([n,m]);
r=floor(n/(2*d));
b=r;
for i=1:d:(d*n);for j=1:d:(d*n);
        Y(i,j)=I(1+(i-1)/(d),1+(j-1)/(d));
    end
end
Ibanda=Y;
n=d*n;
r=(n/d)-1;
AA=ones(r+1,r+1);
for i=0:1:r;
         for j=0:1:r
     AA(i+1,j+1)=Y(d*i+1,d*j+1);
         end 
end
 sincvector=discretsincvector(b,n);
 Irec=Y;
 V1 = ones(r+1,r+1);
 V2 = ones(r+1,r+1);
 v = ones(1, r+1);
 aux = n - d*(0:r);
 for s=0:(n-1);
     v = sincvector(aux+s);
     V1(s+1, :) = v;
 end
 V2=V1';
 Irec = d.^2 * V1 * AA * V2;
 
    function SM = discretsincvector(M,N)
  t = (-N+1):(N-1);
  SM = repmat(double(0), size(t));
  SM( t>0 ) =  sin(pi*(2*M+1)*t(t>0)/N)./(N*sin(pi*t(t>0)/N));
  SM( t<0 ) =  sin(pi*(2*M+1)*(t(t<0)+N)/N)./(N*sin(pi*(t(t<0)+N)/N));
  SM( t==0 ) = (2*M+1)/N;