Normal Map Displayed As RGB Values

I would like to build a normal map displayed as RGB Values like this example Normal Maps. How can I create Normal Maps with Matlab ?

Thanks.

Kind regards.

Gilles

[Debanga]

% Try this example
[X,Y] = meshgrid(1:.1:100,1:.1:100); 
R = sin(Y/1) + eps;
Z = R;
[nx,ny,nz] = surfnorm(X,Y,Z);
b = reshape([nx ny nz], size(nx,1), size(nx,2),3);
b = ((b+1)./2).*255;
imshow(uint8(b));

-DRN