get_axis_aligned_BB.m

function [cx, cy, w, h] = get_axis_aligned_BB(region)
% GETAXISALIGNEDBB extracts an axis aligned bbox from the ground truth REGION with same area as the rotated one
nv = numel(region);
assert(nv==8 || nv==4);

if nv==8
    cx = mean(region(1:2:end));
    cy = mean(region(2:2:end));
    x1 = min(region(1:2:end));
    x2 = max(region(1:2:end));
    y1 = min(region(2:2:end));
    y2 = max(region(2:2:end));
    A1 = norm(region(1:2) - region(3:4)) * norm(region(3:4) - region(5:6));
    A2 = (x2 - x1) * (y2 - y1);
    s = sqrt(A1/A2);
    w = s * (x2 - x1) + 1;
    h = s * (y2 - y1) + 1;
else
    x = region(1);
    y = region(2);
    w = region(3);
    h = region(4);
    cx = x+w/2;
    cy = y+h/2;
end