The algorithm with three unequal phase-shifting steps,neglects the condition that the denominator could be zero in the division operation about the intensity of the image,which leads to the incorrect wrapped phase and incorrect phase unwrapping in the certain region,even the reconstructed object will be misshapen or anamorphic.A novel improved three unequal step length phase-shifting algorithm is presented.The improved algorithm takes into account the phase distribution when the denominator is zero,so some ...