In order to optically refocus three-dimensional (3-D) objects on their real depths, we design an adaptive periodic δ-function array (A-PDFA)-based 3-D optical refocusing method. An A-PDFA kernel with adaptively determined impulse number is first generated, and next by convolving this A-PDFA with the elemental image array (EIA) captured using an integral imaging system, the depth-filtered EIA is obtained to finally refocus the objects on their real depths. Based on simulations and experiments, the performance of the A-PDFA-based 3-D optical refocusing method is confirmed with the widest effective process zone and the highest image quality compared to other classical 3-D optical refocusing methods. Thus, it is believed the proposed method potentially can be used in various 3-D imaging and display applications.
The information warfare needs a highly transparent environment of battlefield, it follows that true three-dimensional display technology has obvious advantages than traditional display technology in the current field of military science and technology. It also focuses on the research progress of lens array imaging technology and aims at what restrict the development of integral imaging, main including low spatial resolution, narrow depth range and small viewing angle. This paper summarizes the principle, characteristics and development history of the integral imaging. A variety of methods are compared and analyzed that how to improve the resolution, extend depth of field, increase scope and eliminate the artifact aiming at problems currently. And makes a discussion about the experimental results of the research, comparing the display performance of different methods.
Integral imaging is known as a promising 3D display method for its ability to reconstruct the light field of the scene. However, integral imaging suffers from low spatial resolution and narrow viewing angle due to the limited spatial bandwidth product of LCD, which prevents its commercial application. In conventional integral imaging display, spatial resolution and viewing angle are two vital factors that should be considered, and many previous research focuses on the two factors. A novel integral imaging 3D display system with large viewing angle about 35° and high spatial resolution for HVS is presented. The method is composed of a high definition 5K LCD panel, a macro lens array and a light shaping diffusor. One point of the method different from conventional integral imaging in which micro lens array is used, a macro lens array with elemental lens diameter 1cm is employed in our method to ensure a large viewing angle, however, this may result in low spatial resolution for HVS. And the other point is a light shaping diffusor is placed in front of the lens array with proper distance, and lifelike 3D reconstruction is obtained. Experimental results with full parallax, large viewing angle and high resolution 3D images are shown to verify the validity of the proposed system.