Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Refocusing from a plenoptic camera within seconds on a mobile phone

[+] Author Affiliations
Óscar Gómez-Cárdenes, José G. Marichal-Hernández, Fernando L. Rosa, Jonas P. Lüke, Juan José Fernández-Valdivia, José M. Rodríguez-Ramos

Univ. de La Laguna (Spain)

Proc. SPIE 9139, Real-Time Image and Video Processing 2014, 913907 (May 15, 2014); doi:10.1117/12.2053186
Text Size: A A A
From Conference Volume 9139

  • Real-Time Image and Video Processing 2014
  • Nasser Kehtarnavaz; Matthias F. Carlsohn
  • Brussels, Belgium | April 14, 2014

abstract

Refocusing a plenoptic image by digital means and after the exposure has been thoroughly studied in the last years, but few efforts have been made in the direction of real time implementation in a constrained environment such as that provided by current mobile phones and tablets. In this work we address the aforementioned challenge demonstrating that a complete focal stack, comprising 31 refocused planes from a (256ff16)2 plenoptic image, can be achieved within seconds by a current SoC mobile phone platform. The election of an appropriate algorithm is the key to success. In a previous work we developed an algorithm, the fast approximate 4D:3D discrete Radon transform, that performs this task with linear time complexity where others obtain quadratic or linearithmic time complexity. Moreover, that algorithm does not requires complex number transforms, trigonometric calculus nor even multiplications nor oat numbers. Our algorithm has been ported to a multi core ARM chip on an off-the-shelf tablet running Android. A careful implementation exploiting parallelism at several levels has been necessary. The final implementation takes advantage of multi-threading in native code and NEON SIMD instructions. As a result our current implementation completes the refocusing task within seconds for a 16 megapixels image, much faster than previous attempts running on powerful PC platforms or dedicated hardware. The times consumed by the different stages of the digital refocusing are given and the strategies to achieve this result are discussed. Time results are given for a variety of environments within Android ecosystem, from the weaker/cheaper SoCs to the top of the line for 2013. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Citation

Óscar Gómez-Cárdenes ; José G. Marichal-Hernández ; Fernando L. Rosa ; Jonas P. Lüke ; Juan José Fernández-Valdivia, et al.
" Refocusing from a plenoptic camera within seconds on a mobile phone ", Proc. SPIE 9139, Real-Time Image and Video Processing 2014, 913907 (May 15, 2014); doi:10.1117/12.2053186; http://dx.doi.org/10.1117/12.2053186


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.