def retroprojectsubject(camera, subject):
ih = camera.inverse_homography
sb = subject.h_base
st = subject.h_top
uvb = np.array([[sb[0]], [sb[1]], [1]])
uvt = np.array([[st[0]], [st[1]], [1]])
db = ih.dot(uvb)
dt = ih.dot(uvt)
db = db / db[2]
dt = dt / dt[2]
subject.setretroprojection(db, dt)
def __gethomography(self):
r = self.rotation
t = self.translation
h = np.array([[r[0, 0], r[0, 1], t[0]], [r[1, 0], r[1, 1], t[1]],
[r[2, 0], r[2, 1], t[2]]])
self.homography = h / t[2]
self.inverse_homography = np.linalg.inv(self.homography)
