Vol. 51, Issue 2, pp. 257-269 (2021)

Vol. 51 Issue 2 pp. 257-269

The effect of noise, a constant background, and bit depth on the phase retrieval of pure phase objects

Varis Karitans, Andrejs Tokmakovs, Adele Antonuka

Keywords

phase retrieval, phase problem, diffraction

Abstract

In the current study, we investigate the effect of uniform white noise, Poisson noise and a constant background on the phase retrieval of pure phase objects. We also study the influence of the aforementioned factors on phase retrieval at different bit depths of intensity measurements. An algorithm called PhaseLift is used for phase retrieval as it requires a small number of modulating masks and can retrieve the phase of an object from sparse intensity measurements of low bit depth. A test object is modulated by eight random masks generated from a single mask and the phase of the object is retrieved from coded diffraction patterns. Different levels of uniform white noise, Poisson noise and constant background are superimposed on the diffraction patterns and the root-mean-square error (RMSE) of the retrieved object is calculated at each level. The results suggest that Poisson noise and a constant background at the same level cause similar RMSE compared to uniform white noise. Lowering the bit depth from 18-bits to 14-bits resulted in the decrease of the RMSE caused by Poisson noise and a constant background. We conclude that the effects of noise and constant background can be reduced by lowering the bit depth.

Vol. 51
Issue 2
pp. 257-269

3.79 MB

Corresponding address

Optica Applicata
Wrocław University of Science and Technology
Faculty of Fundamental Problems of Technology
Wybrzeże Wyspiańskiego 27
50-370 Wrocław, Poland

Publisher

Wrocław University of Science and Technology
Faculty of Fundamental Problems of Technology
Wybrzeże Wyspiańskiego 27
50-370 Wrocław, Poland

Contact us

  • optica.applicata@pwr.edu.pl
  • +48 71 320 23 93
  • +48 71 328 36 96