The ghost-free condition is proposed to avoid the ghosting effect caused by the insufficient sampling rate when rendering the multi-layer scenes by the light-field method.It is shown that the optimal constant depth and the maximum camera interval can be determined by the scene geometry and the angular resolution of the camera.Also,a quantitative experiment is used to verify the presented condition.The peak signal-to-noise ratio(PSNR) between the rendered views and the standard views is calculated to show th...