A method for improving the viewing quality of integral imaging (II) is proposed, based on using an aperture-tunable lens array (LA). The proposed method uses a liquid crystal (LC) panel without a backlighting unit to tune the aperture of an LA dynamically. The shape and transmittance of the aperture can be controlled arbitrarily by programming the state of the pixels on the LC panel. Adding the temporal multiplexing technique, the viewing quality can be improved by the after-image effect of the human eye. Moreover, the relationships between the lateral resolution and the aperture tuning pattern and the depth of field and the aperture tuning pattern are derived, respectively. The product of the depth of field, the lateral resolution squared, and the lateral viewing range is proposed as a new figure of merit for an II system. Experimental results show the validity of the proposed method.