A Software Tool for Refocusing of Light Fields




Sun, Canyu

Journal Title

Journal ISSN

Volume Title



In this project, an interactive software tool is designed for volumetric refocusing of a light field (LF) by using a post-capture refocusing technique. This software tool aims to help people like traditional photographers who do not know LFs to understand what the refocus of LF is and how the bokeh is generated. LF emerges as a technology allowing to capture richer visual information which is a higher dimensional representation of visual data. The spectral region of support (ROS) of a Lambertian point at a constant depth is shown to be two hyperfans in four-dimensional (4-D) frequency domain. Based on the spectral analysis, a 4-D finite-extent impulse response (FIR) hyperfan filter is designed for refocusing of the LF. Two filter parameters can be changed to result in different visual effect of the refocused images, namely α and θ. Experiments are conducted to evaluate the effect of these two parameters by using LFs of different size. Comparisons and analyses are made using different LFs and different parameters. Based on these comparisons, conclusions are drawn about the effect of fan filters on the quality of the refocused images. It is found that filter parameter α controls the depth of the focal plane and θ controls the depth of field (DOF) of the refocused image. Furthermore, the structure of the software and the design of each function is described. The software can be used to display a LF as a video, display the center image of the LF, display the refocused image and the figure of the filter used as well as extracting central images of the LF. The interactive user interface makes the refocusing of LFs easier.