%%%
%%% Error function for non-linear minimization on the camera paramters (M)
%%%

function [err] = errfuncperspM( X, W, S, Test, Ncamera, Npoint )

   rot = rotmat( X(1), X(2), X(3) );
   trans = X(4:6);
   i     = rot(1,:);
   j     = rot(2,:);
   k     = rot(3,:);
   den   = k*S - k*trans'*ones(1,Npoint);
   U     = (i*S - i*trans'*ones(1,Npoint))./den;
   V     = (j*S - j*trans'*ones(1,Npoint))./den;

   West  = [U ; V];
   West  = West - Test * ones(1,Npoint);

   err   = sum( (W(1,:) - West(1,:)).^2 + (W(2,:) - West(2,:)).^2 );