Optical performance analysis of plenoptic camera systems

Abstract

Adding an array of microlenses in front of the sensor transforms the capabilities of a conventional camera to capture both spatial and angular information within a single shot. This plenoptic camera is capable of obtaining depth information and providing it for a multitude of applications, e.g. artificial re-focusing of photographs. Without the need of active illumination it represents a compact and fast optical 3D acquisition technique with reduced effort in system alignment. Since the extent of the aperture limits the range of detected angles, the observed parallax is reduced compared to common stereo imaging systems, which results in a decreased depth resolution. Besides, the gain of angular information implies a degraded spatial resolution. This trade-off requires a careful choice of the optical system parameters. We present a comprehensive assessment of possible degrees of freedom in the design of plenoptic systems. Utilizing a custom-built simulation tool, the optical performance is quantified with respect to particular starting conditions. Furthermore, a plenoptic camera prototype is demonstrated in order to verify the predicted optical characteristics

Depth and angular resolution in plenoptic cameras

“…We validate the SPC-based depth and angular resolution extractors results against the Zemax simulation results from [8].…”

“…For this purpose, we build the SPC model of the plenoptic camera configuration stated in [8], and apply the defined depth and resolution extractors. Figure 5 illustrates resolvable depth planes for every one pixel parallax in the microimages captured by the neighbouring microlenses.…”

“…Analytical and model based approaches have been utilized for quantifying the performance of a plenoptic camera such as the efforts in [6,7,8]. An analytical approach for calculating the spatial resolution in a multi-focus plenoptic camera is also presented in [9].…”

“…Experimental approaches are located in the other end of the complexity spectrum for evaluating plenoptic cameras. Examples of such approaches can be found in [8,10,11]. Experimental approaches are too expensive since they need a controlled environment, proper equipments and a minimum level of expertise.…”

“…The SPC model is bound to the realm of the geometrical optics which gives a wider scope compared to e.g. the paraxial ray model utilized in [6,8]. Considering the above advantages, this work focuses on quantifying the angular and depth resolution in a plenoptic camera using the SPC model.…”