OSA's Digital Library

Biomedical Optics Express

Biomedical Optics Express

  • Editor: Joseph A. Izatt
  • Vol. 4, Iss. 1 — Jan. 1, 2013
  • pp: 89–104

Effect of signal intensity and camera quantization on laser speckle contrast analysis

Lipei Song and Daniel S. Elson  »View Author Affiliations

Biomedical Optics Express, Vol. 4, Issue 1, pp. 89-104 (2013)

View Full Text Article

Enhanced HTML    Acrobat PDF (2252 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



Laser speckle contrast analysis (LASCA) is limited to being a qualitative method for the measurement of blood flow and tissue perfusion as it is sensitive to the measurement configuration. The signal intensity is one of the parameters that can affect the contrast values due to the quantization of the signals by the camera and analog-to-digital converter (ADC). In this paper we deduce the theoretical relationship between signal intensity and contrast values based on the probability density function (PDF) of the speckle pattern and simplify it to a rational function. A simple method to correct this contrast error is suggested. The experimental results demonstrate that this relationship can effectively compensate the bias in contrast values induced by the quantized signal intensity and correct for bias induced by signal intensity variations across the field of view.

© 2012 OSA

OCIS Codes
(030.6140) Coherence and statistical optics : Speckle
(170.3880) Medical optics and biotechnology : Medical and biological imaging

ToC Category:
Speckle Imaging and Diagnostics

Original Manuscript: September 17, 2012
Revised Manuscript: November 5, 2012
Manuscript Accepted: November 28, 2012
Published: December 13, 2012

Lipei Song and Daniel S. Elson, "Effect of signal intensity and camera quantization on laser speckle contrast analysis," Biomed. Opt. Express 4, 89-104 (2013)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. Z. Luo, Z. Yuan, M. Tully, Y. Pan, and C. Du, “Quantification of cocaine-induced cortical blood flow changes using laser speckle contrast imaging and Doppler optical coherence tomography,” Appl. Opt.48(10), D247–D255 (2009). [CrossRef] [PubMed]
  2. N. Li, X. F. Jia, K. Murari, R. Parlapalli, A. Rege, and N. V. Thakor, “High spatiotemporal resolution imaging of the neurovascular response to electrical stimulation of rat peripheral trigeminal nerve as revealed by in vivo temporal laser speckle contrast,” J. Neurosci. Methods176(2), 230–236 (2009). [CrossRef] [PubMed]
  3. Z. C. Luo, Z. J. Yuan, Y. T. Pan, and C. W. Du, “Simultaneous imaging of cortical hemodynamics and blood oxygenation change during cerebral ischemia using dual-wavelength laser speckle contrast imaging,” Opt. Lett.34(9), 1480–1482 (2009). [CrossRef] [PubMed]
  4. R. Bezemer, M. Legrand, E. Klijn, M. Heger, I. C. J. H. Post, T. M. van Gulik, D. Payen, and C. Ince, “Real-time assessment of renal cortical microvascular perfusion heterogeneities using near-infrared laser speckle imaging,” Opt. Express18(14), 15054–15061 (2010). [CrossRef] [PubMed]
  5. A. B. Parthasarathy, S. M. S. Kazmi, and A. K. Dunn, “Quantitative imaging of ischemic stroke through thinned skull in mice with Multi Exposure Speckle Imaging,” Biomed. Opt. Express1(1), 246–259 (2010). [CrossRef] [PubMed]
  6. R. C. Bray, K. R. Forrester, J. Reed, C. Leonard, and J. Tulip, “Endoscopic laser speckle imaging of tissue blood flow: applications in the human knee,” J. Orthop. Res.24(8), 1650–1659 (2006). [CrossRef] [PubMed]
  7. C. J. Stewart, R. Frank, K. R. Forrester, J. Tulip, R. Lindsay, and R. C. Bray, “A comparison of two laser-based methods for determination of burn scar perfusion: laser Doppler versus laser speckle imaging,” Burns31(6), 744–752 (2005). [CrossRef] [PubMed]
  8. D. D. Duncan and S. J. Kirkpatrick, “Can laser speckle flowmetry be made a quantitative tool?” J. Opt. Soc. Am. A25(8), 2088–2094 (2008). [CrossRef] [PubMed]
  9. P. Zakharov, A. Völker, A. Buck, B. Weber, and F. Scheffold, “Quantitative modeling of laser speckle imaging,” Opt. Lett.31(23), 3465–3467 (2006). [CrossRef] [PubMed]
  10. J. W. Goodman, Speckle Phenomena in Optics: Theory and Applications (Ben Roberts & Company, 2007).
  11. S. J. Kirkpatrick, D. D. Duncan, and E. M. Wells-Gray, “Detrimental effects of speckle-pixel size matching in laser speckle contrast imaging,” Opt. Lett.33(24), 2886–2888 (2008). [CrossRef] [PubMed]
  12. S. Yuan, A. Devor, D. A. Boas, and A. K. Dunn, “Determination of optimal exposure time for imaging of blood flow changes with laser speckle contrast imaging,” Appl. Opt.44(10), 1823–1830 (2005). [CrossRef] [PubMed]
  13. J. A. Zadnik and J. W. Beletic, “Effect of CCD Readout Noise in Astronomical Speckle Imaging,” Appl. Opt.37(2), 361–368 (1998). [CrossRef] [PubMed]
  14. T. L. Alexander, J. E. Harvey, and A. R. Weeks, “Average speckle size as a function of intensity threshold level: comparisonof experimental measurements with theory,” Appl. Opt.33(35), 8240–8250 (1994). [CrossRef] [PubMed]
  15. J. C. Dainty, Laser Speckle and Related Phenomena (Springer-Verlag, 1975).
  16. R. Bandyopadhyay, A. S. Gittings, S. S. Suh, P. K. Dixon, and D. J. Durian, “Speckle-visibility spectroscopy: A tool to study time-varying dynamics,” Rev. Sci. Instrum.76(9), 093110 (2005). [CrossRef]
  17. T. Smausz, D. Zölei, and B. Hopp, “Real correlation time measurement in laser speckle contrast analysis using wide exposure time range images,” Appl. Opt.48(8), 1425–1429 (2009). [CrossRef] [PubMed]
  18. A. B. Parthasarathy, W. J. Tom, A. Gopal, X. J. Zhang, and A. K. Dunn, “Robust flow measurement with multi-exposure speckle imaging,” Opt. Express16(3), 1975–1989 (2008). [CrossRef] [PubMed]
  19. H. Zhang, P. Li, N. Feng, J. Qiu, B. Li, W. Luo, and Q. Luo, “Correcting the detrimental effects of nonuniform intensity distribution on fiber-transmitting laser speckle imaging of blood flow,” Opt. Express20(1), 508–517 (2012). [CrossRef] [PubMed]
  20. P. Li, S. Ni, L. Zhang, S. Zeng, and Q. Luo, “Imaging cerebral blood flow through the intact rat skull with temporal laser speckle imaging,” Opt. Lett.31(12), 1824–1826 (2006). [CrossRef] [PubMed]
  21. H. Zhang, P. Li, N. Feng, J. Qiu, B. Li, W. Luo, and Q. Luo, “Correcting the detrimental effects of nonuniform intensity distribution on fiber-transmitting laser speckle imaging of blood flow,” Opt. Express20(1), 508–517 (2012). [CrossRef] [PubMed]
  22. J. W. Goodman, Statistical Optics (Wiley, 1985).
  23. A. M. S. Maallo, P. F. Almoro, and S. G. Hanson, “Quantization analysis of speckle intensity measurements for phase retrieval,” Appl. Opt.49(27), 5087–5094 (2010). [CrossRef] [PubMed]
  24. D. D. Duncan, S. J. Kirkpatrick, and R. K. Wang, “Statistics of local speckle contrast,” J. Opt. Soc. Am. A25(1), 9–15 (2008). [CrossRef] [PubMed]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited