Nearest-Neighbour-Search-Neural-Networks-Product-Quantization/MNIST/Functions/Vector2PictureMatrix.m

%% Vector to 3D Matrix containing N images
%  The function provides convertion from a Vector containing N grayscale 
%  [0, 255] layers pictures  of square size ImgSz*ImgSz [px] in a 3D Matrix
%  containing N layers, each one of them will contain a single picture.
% 
%  Inputs: 
% - imgSz   Size of the single squared picture
% - N       Total Number of pictures
% - Xset    Input Vector
% 
%  Outputs:
% - Xmat    3D Matrix containing the pictures
%%

%% Filling the Matrix
%  The for cycles loop over the Vector Xset: the outer cycle runs over the N pictures,
%  the inner cycle copies a row of each picture to the current one.
%%

function Xmat = Vector2PictureMatrix(imgSz, N, Xset)

Xmat = zeros(imgSz,imgSz, N,'uint8');

for ii=1:N  
    for jj=1:imgSz
        Xmat(jj,:,ii)=Xset((ii-1)*imgSz^2+(jj-1)*imgSz+1:(ii-1)*imgSz^2+jj*imgSz);
    end
end

end