Matlab code

function [Ri] = interp2c(pos_x_total,pos_y_total,R) %linear interpolation %(i,j)--->(pos_x(i,j),pos_y(i,j)) [m,n] = size(R); Ri=zeros(m,n); for i=1:m for j=1:n x=pos_x_total(i,j); y=pos_y_total(i,j); if (x>= m) x=m; ceil_x=m; floor_x=ceil_x-1; else if (x<=1) x=1; end floor_x=floor(x); ceil_x=floor_x+1; end if (y>= n) y=n; ceil_y=n; floor_y=ceil_y-1; else if (y<=1) y=1; end floor_y=floor(y); ceil_y=floor_y+1; end Ri(i,j)=R(ceil_x,ceil_y)*(x-floor_x)*(y-floor_y)+R(floor_x,floor_y)*(ceil_x-x)*(ceil_y-y)+R(floor_x,ceil_y)*(ceil_x-x)*(y-floor_y)+R(ceil_x,floor_y)*(x-floor_x)*(ceil_y-y); end end end