Transfer Efficiency and Depth Invariance in Computational Cameras

Jongmin Baek

Proc. IEEE International Conference on Computational Photography, March 2010

Relative transfer efficiency and depth invariance of computational cameras

Figure. Top: the transfer efficiency of the given lenses.
Bottom: the depth variance of the given lenses.


Recent advances in computational cameras achieve extension of depth of field by modulating the aperture of an imaging system, either spatially or temporally. They are, however, accompanied by loss of image detail, the chief cause of which is low and/or depth-varying frequency response of such systems. In this paper, we examine the tradeoff between achieving depth invariance and maintaining high transfer efficiency by providing a mathematical framework for analyzing the transfer function of these computational cameras. Using this framework, we prove mathematical bounds on the efficacy of the tradeoff. These bounds lead to observations on the fundamental limitations of computational cameras. In particular, we show that some existing designs are already near-optimal in our metrics.

Paper (PDF; 473 KB): Link

Supplement (PDF; 127 KB; Fast Computation of the OTFs for Various Computational Cameras): Link

Slides: (PDF; 3.9 MB): Link

  author = {Baek, Jongmin},
  title = {Transfer efficiency and depth invariance in computational cameras},
  booktitle = {Proceedings of IEEE International Conference on Computational Photography 2010},
  issue_date = {March 2010},
  month = {March},
  year = {2010},
  pages = {1-8},
  doi = 10.1109/ICCPHOT.2010.5585098}