Dynamic laser speckle for non-destructive quality evaluation of bread

E. Stoykova; B. Ivanov; M. Shopova; T. Lyubenova; I. Panchev; V. Sainov

doi:10.1117/12.881922

17 January 2011 Dynamic laser speckle for non-destructive quality evaluation of bread

E. Stoykova, B. Ivanov, M. Shopova, T. Lyubenova, I. Panchev, V. Sainov

Proceedings Volume 7747, 16th International School on Quantum Electronics: Laser Physics and Applications; 77470L (2011) https://doi.org/10.1117/12.881922
Event: XVI International School on Quantum Electronics: Laser Physics and Applications, 2010, Nessebar, Bulgaria

Abstract

Coherent illumination of a diffuse object yields a randomly varying interference pattern, which changes over time at any modification of the object. This phenomenon can be used for detection and visualization of physical or biological activity in various objects (e.g. fruits, seeds, coatings) through statistical description of laser speckle dynamics. The present report aims at non-destructive full-field evaluation of bread by spatial-temporal characterization of laser speckle. The main purpose of the conducted experiments was to prove the ability of the dynamic speckle method to indicate activity within the studied bread samples. In the set-up for acquisition and storage of dynamic speckle patterns an expanded beam from a DPSS laser (532 nm and 100mW) illuminated the sample through a ground glass diffuser. A CCD camera, adjusted to focus the sample, recorded regularly a sequence of images (8 bits and 780 x 582 squared pixels, sized 8.1 × 8.1 μm) at sampling frequency 0.25 Hz. A temporal structure function was calculated to evaluate activity of the bread samples in time using the full images in the sequence. In total, 7 samples of two types of bread were monitored during a chemical and physical process of bread's staling. Segmentation of images into matrixes of isometric fragments was also utilized. The results proved the potential of dynamic speckle as effective means for monitoring the process of bread staling and ability of this approach to differentiate between different types of bread.

Citation Download Citation

E. Stoykova, B. Ivanov, M. Shopova, T. Lyubenova, I. Panchev, and V. Sainov "Dynamic laser speckle for non-destructive quality evaluation of bread", Proc. SPIE 7747, 16th International School on Quantum Electronics: Laser Physics and Applications, 77470L (17 January 2011); https://doi.org/10.1117/12.881922

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available