mobili.m

function [B, finalError] = mobili(seq, frm, id, label_dir)
% label_dir directory path must be relative to './devkit/matlab' directory
  avgCarHeight = 1.5208;
  avgCarLength = 3.8600;
  
  h = avgCarHeight; % Average height of camera from the ground plane
  K = [
        721.53, 0, 609.55;
        0, 721.53, 172.85;
        0, 0, 1;
      ];            % Camera intrinsics matrix
  n = [0, -1, 0]';  % Unit normal vector perpendicular to ground plane
  
  trackletFields = getTracklets(seq, frm, id, label_dir);
  B = [];           % Matrix to store 3D projection vectors of all instances
  finalError = [];  % Comparision between estimates and actual measurements
  
  for i=1:numel(seq)
    b = [(trackletFields(i, 4) + trackletFields(i, 6)) / 2, trackletFields(i, 7), 1]'; % Midpoint from left and right ends and on the bottom part
    proj = -(h * inv(K) * b) / (n' * inv(K) * b);
    proj = proj + [0; -avgCarHeight/2; avgCarLength/2]; % In 3D, move up in vertical direction and move inward to arrive at midpoint of 3D projection cube
    B = [B; proj'];
    finalError = [finalError; abs(proj' - trackletFields(i, 9:11))];
  end
end