def METHOD_NAME(self, point2d):
    iK = inv(self.K)
    Pi=np.array([point2d[0]/point2d[2],point2d[1]/point2d[2],1.0],dtype=np.double).reshape(3,1)
    a=np.dot(iK,Pi)
    aH=np.array([a[0],a[1],a[2],1],dtype=np.double)
    RT2=self.RT.copy()
    RT2[0,3] = 0
    RT2[1,3] = 0
    RT2[2,3] = 0
    RT2[3,3] = 1
    b = np.dot(np.transpose(RT2),aH)
    translate = np.identity(4,dtype=np.double)
    translate[0,3] = self.RT[0,3]/self.RT[3,3];
    translate[1,3] = self.RT[1,3]/self.RT[3,3];
    translate[2,3] = self.RT[2,3]/self.RT[3,3];
    b=np.dot(translate,b)
    outPoint = np.array([b[0]/b[3],b[1]/b[3],b[2]/b[3],1])
    return outPoint