Time History Of Speckle Pattern Research Articles

Laser biospeckle technique for characterizing the impact of temperature and initial moisture content on seed germination

In this paper, we present laser biospeckle technique for analyzing the impact of temperature regimes and initial moisture content on germination characteristics of soybean seeds. A method is proposed to evaluate the optimum values of recording angle and speckle size for standardizing the experimental parameters. Moreover, to enhance accuracy of the technique, a new procedure based on full-field time history of speckle pattern (FTHSP) for numerical quantification of biospeckle activity (BA) is proposed. Investigations indicate that the BA is significantly (p<0.05) dependent on temperature and initial moisture content of seed during germination. Obtained data revealed that these two factors regulated the time required to complete the germination process. The results are benchmarked with standard laboratory test by calculating imbibition rate and germination percentage. These standard laboratory tests are also in agreement with the results acquired by using biospeckle technique. Significant positive correlation (p < 0.01) between BA and standard germination tests proves applicability of biospeckle analysis as an efficient tool for rapidly evaluating the impact of temperature and initial moisture content on seed germination characteristics. Furthermore, it was also found that both recording angle and size of speckle grains affect the quality of speckle patterns which influence overall accuracy of the analysis. The key advantages of proposed analysis technique are full-field analysis, consideration of optical inhomogeneity present in the samples, lower computation time and complexity (as compared to other full-field techniques), zero standard deviation, and independent of image background.

Biophototic in azuki bean seeds treated with ultrahigh dilutions

Seed analysis is usually performed by destructive samples with time-consuming methods. Treatments that improve seed vigor are suggested based on bioassays and protocols for most plants. This includes the use of images to assess quality and pro- vide information that supports decisions. However, instrumental cost has not made these technologies widely used. The objective of this research was to study biophotonic images generated by low cost technologies - cold plasma scanner or gas discharge visualization (GDV) and speckle laser (BSL) - to evaluate the germination of adzuki beans seeds treated with ultrahigh dilutions (UHD). The research was carried out at the EPAGRI Homeopathy and Plant Health Laboratory, with a post-graduate support at the State University of Santa Catarina (UDESC). The images of the seeds were diagnosed mathematically, before and after germination, using “Local Connected Fractal Dimension Analysis” (LCFD) and “Time History Speckle Pattern” (THSP). The results show that the images identify the effects of high dilution - Bryonia alba and Silicea terra, at 6, 12 and 30 CH (centesimal hahnemannian dilution order) - on the seeds of azuki beans. There were statistically differences (p &lt; 1% and p &lt; 5%) of the treatments in relation to the control: water. Only Silicea terra 30CH inhibited seed germination. The signals found in the BSL images of the seeds were superior to the GDV signals, showing an average of 89% correct responses (BSL) against 87% (GDV).

Biological activity using dynamic speckle in blood serum of mares in different reproductive stages

This study aimed to evaluate the biological activity in blood serum plasma samples from mares at different reproductive stages using dynamic speckle analysis. For this purpose, samples were collected from 40 Mangalarga Machador mares from the Formoso 2S horse farm in Cajueiro, AL. The mares were classified into four groups of ten animals each according to the pregnancy stage: ten empty mares (not pregnant), ten pregnant mares in the early third of pregnancy between one month and four months, ten pregnant mares in the final third of the pregnancy between seven and eleven months, and ten lactating mares (within two months post-partum). The biological activity response using a dynamic speckle (biospeckle) was obtained by capturing images reflected by a coherent light (diode laser with a wavelength of 532 nm and intensity of 3 mW) on a sample using a CCD (charge coupled device) camera. This data was analyzed using image processing techniques through the computational application Speckle-THSP-MCO-Descritores (STMD), applying THSP (time history speckle pattern) methodology, which evaluates the temporal evolution of the interference image from spreading over the sample surface over time. A coherence matrix generated from the THSP was used to present the intensity module dispersion, which provided the bioactivity data. These data were then processed using the program OriginPro 8. Ink, generate graphs and compare the results from the different groups under study. A general biospeckle signature was observed regardless of the mares’ reproductive stage considered in this study. A short phase of movement of the samples associated with an accommodation of the drop on the slide was observed. It was followed by an ascending curve starting between 5 and 10 min of observation, reaching a peak within 15 and 25 min, and finally decayed uniformly until almost zero after 45 min. The group of pregnant mares in the final third of pregnancy presented superior bioactivity compared to pregnant mares in the early third of pregnancy. The curve observed for the group of lactating mares is similar to the curve obtained for the group of pregnant mares in the early third of pregnancy. Bioactive molecules act as dispersion elements of coherent light incident on a sample. The variation inherent to the presence of bioactive molecules in the different stages evaluated influenced the biospeckle pattern detected in each sample. It was concluded that the biological activity peaks of the blood plasma samples from the mares evaluated in this study using the dynamic speckle analysis technique were different for both amplitude and time of occurrence, according to the different reproductive stages.

Poincare sphere noise filtering for singularities in dynamic speckle activity: Application to paint drying time measurement

We present an approach based on optical vortex density to characterize a dynamic process. The proposal is tested in real experiments involving the drying of paint as case study. In this case, speckle patterns are generated by coherent light scattered from the sample. The dynamic behavior of the speckle pattern during the paint drying is evaluated by using Time History of Speckle Pattern (THSP). The THSP's pseudo-phase representation is calculated via a two-dimensional Laguerre Gauss transform algorithm. The singular points in the pseudo-phase are then identified, then the number of phase singularities are evaluated over all the pseudo-phase representations of the THSP sequence.A comparison between the number of the phase singularities in THSP sequences and the gravimetric curve shows that the results are in good agreement for the active period. However, for very low activity periods noise vortices are obtained. The noise vortices are originated in the camera recoding and digitalization process. We propose the use of Stokes Parameters to configure a Vortex-Filter in order to eliminate noise vortices in each paint-drying measurement, this filter is represented using Poincare Sphere for visualization purposes. In all cases, the drying evolution curve obtained by using the optical vortex density and the Poincare Sphere filter present a good agreement with gravimetric curve, indicating that the proposed method is a valid measuring alternative.

Evaluation of the quality of the shielded metal arc welding process using speckle interferometry

Speckle, which is a branch of optics that studies the interference pattern caused by the incidence of coherent light in a material’s surface, has some optical techniques and methods that can be successfully applied to determine properties of materials. In this work we used the method called THSP, Time History Speckle Pattern, in samples made of AISI 1020 carbon steel that were submitted to the shielded metal arc welding (SMAW) process, with the objective of identifying (qualitatively) the level of irregularity on its welded surface, by comparing these samples with a default sample, made with the same material. The technique of spekle by reflection was used for data collection. The results showed quantitative diferences between the default welded sample and the other samples, and there are good perspectives that speckle can be applied to determine the quality of the welding process, since the results showed more accuracy than visual inspection.

Bio Metrological Assessment of Shelf-life of Azadirachta Indica

The concentration and activity of water in Azadirachta indica describes the shelf life of Neem. The physical and chemical properties of many biological materials depends on the level of water content, which affects the maturity of the fruits and vegetables. Biospeckle technique is a tool used for contrast analysis and hence distinguishes the water activities at different stages in shelf-life of the specimen. Decomposing condition of Azadirachta indica is evaluated by Time History of Speckle Pattern (THSP) during different stages with histogram analysis and fractal box counting methods.

Fractal box-counting technique for shelf life study of grapes by laser speckle image processing

Background: In agriculture, it is essential to follow the ripening of fruits and vegetables which is a subject of interest economically. The use of optical non-destructive method is the most suitable technique for evaluating the ripening stage of fruits when they ripen off-tree and eventually to predict the optimum storage life. Many methods are recently developed in optical image processing. The texture correlation function and the fractal box counting (FBC) of biospeckle pattern have been described. Materials and Methods: The dynamic speckle patterns known as boiling speckle are produced by a coherent light illumination incident on the active material of biological tissue. A high coherent laser source He-Ne with 632 nm with neutral density filter and charge-coupled device camera are the major components of the experimental setup. The same experiment may be done by a green laser of wavelength 541 nm (green color). The same procedure continues to take the speckle images in periodically. Results and Discussion: With the help of FBC method in image processing technique, we can assess optically rough surface fruits such as grapes in this work. According to the FBC theory, the speckle images (R1) give a binary counting value D = 1.7640 at the initial stage. Gray image converted into binary image which gives the fractal counting value D = 1.7554 at later on phase. It means that the specimen (grapes) becomes dry periodically and its value is affected by the surrounding environmental condition. Conclusion: Using the dynamic speckle phenomenon or biospeckle method, we demonstrated the assessment of shelf life activity of grapes. The visual phase of the autocorrelation function gives reliable results showing the variation in activity because of the internal changes caused by decreasing water content and then becomes dry grape stage. The correlation function of speckle patternand the Fractal Box Counting (FBC) technique has been proposed as a tool to estimate the postharvest stage of grapes. The bioactivities of fruits and vegetable materials are based on Brownian motion, due to subcellular organs. This indicates the senescence or biological aging characteristics. The quantification of the biospeckle phenomena is associated with the moment of inertia, time history of speckle pattern and grey level co-occurrence matrix. We proposed a new FBC technique to assess the shelf life of grapes.

Assessment of biological leaf tissue using biospeckle laser imaging technique

We report on the application of an optical imaging technique, the biospeckle laser, as a potential tool to assess biological and medicinal plant leaves. The biospeckle laser technique is a non-invasive and non-destructive optical technique used to investigate biological objects. Just after their removal from plants, the torn leaves were used for biospeckle laser imaging. Quantitative evaluation of the biospeckle data using the inertia moment (IM) of the time history speckle pattern, showed that the IM can be utilized to provide a biospeckle signature to the plant leaves. It showed that leaves from different plants can have their own characteristic IM values. We further investigated the infected regions of the leaves that display a relatively lower biospeckle activity than the healthy tissue. It was easy to discriminate between the infected and healthy regions of the leaf tissue. The biospeckle technique can successfully be implemented as a potential tool for the taxonomy of quality leaves. Furthermore, the technique can help boost the quality of ayurvedic medicines.

Towards real-time speckle image processing for mealiness assessment in apple fruit

ABSTRACTBiospeckle activity (during 1–25 s) of ‘Red Delicious’ apples was recorded under 680 and 780 nm laser diodes. The time history speckle pattern (THSP) images were configured and evaluated using the common biospeckle and texture descriptors. Several artificial neural networks (ANN) models were developed to predict the stiffness and juiciness of apple fruits. At the recording time of 1 s and 680 nm laser diode, the ANN models developed by texture features showed better performance in prediction of stiffness (r = 0.70 and SEP = 8.4 kN) and juiciness (r = 0.68 and SEP = 2.3 cm2) as compared to the common biospeckle features-based ones (r = 0.25 and SEP = 11.3 kN m−1 for stiffness and r = 0.29 and SEP = 3.1 cm2for juiciness). Furthermore, classification of apples into fresh, semi-mealy, and mealy groups was carried out. At the recording time of 25 s and 680 nm laser, the ANN models developed by texture features classified fresh, semi-mealy, and mealy apples with accuracies of 86.3, 65.9, and 95.5%, respectively. Reduction of the recording time to 1 s resulted in the classification accuracies of 88.2, 68.5, and 85.5% for mealy, semi-mealy, and mealy apples compared to the common biospeckle features-based ANN models with the accuracies of 82.8, 50.7, and 46.8%, respectively. These results indicated that the texture descriptors had better performance at shorter recording times in comparison with the biospeckle features which are commonly used in evaluation of biospeckle images, even though more improvements are still required.

Study of drying process of paint by dynamic speckle with B/D pixel counting technique

The aim of the work is the assessment of drying process of latex paint by dynamic Laser speckle method. The basic concept of dynamic speckle technique is described. Laser light scattering by water borne sample is a time dependent surface activity. The variation of laser speckle intensity is due to the change of refractive index and the particle movements of the latex paint. A novel method, B/D counting technique to measure the dynamic activity of drying paint using co-occurrence matrix of Time History of Speckle Pattern (THSP) is presented. The result of drying process of latex paint by dynamic laser speckle method is compared with the gravimetric method and agreed well.

Measurement of shrinkage during photopolymerization of methacrylate resins by interferometric techniques: Local and global analyses

Light based measurement techniques have largely proven its efficiency on polymer materials. In this study we describe a method based on specific optical techniques for characterization of dental composites. First, a Dynamic Speckle Pattern (DSP) global analysis was made, which allowed qualitative descriptions of the behavior of samples during polymerization from their upper surface view. This analysis is complemented with local measurements of shrinkage by means of a fiber optic Fizeau Interferometer. Second, a Time History Speckle Pattern (THSP) analysis of different samples was carried out in order to gain a better understanding of the shrinkage development as the polymerization reaction takes place. To show the virtues of these techniques, we applied them to both a commercial resin dental composite and a model resin based on methacrylate monomers. Both techniques could serve as a good comparing test protocol among different commercial resins.

Assessment of bio-activity using the methods of inertia moment and absolute value of the differences

In this paper, a numerical analysis of the time history of speckle pattern (THSP) has been carried out by means of a co-occurrence matrix (COM) that assembles the intensity distributions of speckle pattern of the specimen with regard to time. Experiments have been performed to implement inertia moment (IM) and absolute value of the differences (AVD) methods on the biospeckle COMs. In the present work, we have used three different Indian fruits namely pear, apple and tomato for the study of bio-activities using above methods for the first time. The variation of IM and AVD with frequency is found to increase for all the fruits but apple has relatively higher rate of increase of IM and AVDs in comparison to pear and tomato. In addition, the value IM for the fruits is found to decrease with the aging of the sample but apple has relatively lower rate of decrease of IM in comparison to pear and tomato.

Use of time history speckle pattern and pulsed photoacoustic techniques to detect the self-accommodating transformation in a Cu–Al–Ni shape memory alloy

Continuous and pulsed electromagnetic radiation was used to detect the self-accommodation mechanism on a polycrystalline Cu–13.83 wt.%Al–2.34 wt.%Ni shape memory alloy. Rectangular samples of this alloy were mechanically polished to observe the austenite and martensite phases. The samples were cooled in liquid nitrogen prior to the experiments to obtain the martensite phase. Using a dynamic speckle technique with a continuous wave laser we obtained the time history of the speckle pattern image and monitored the surface changes caused by the self-accommodation mechanism during the inverse (martensitic to austenitic) transformation. Using a photoacoustic technique based on a pulsed laser source it was also possible to detect the self-accommodation phenomena in a bulk sample. For comparison purposes, we used differential scanning calorimetry (DSC) to detect the critical temperatures of transformation and use these as reference to evaluate the performance of the optical and photoacoustical techniques. In all cases, the same range of temperature was obtained during the inverse transformation. From these results, we conclude that time history speckle pattern (THSP) and pulsed photoacoustic are complementary techniques; they are non-destructive and useful to detect surface and bulk martensitic transformation induced by a temperature change.

Time history speckle pattern under statistical view

The dynamic speckle analysis has been done because speckle interference began to be evaluated as an important source of information, especially those related to biological samples under laser beam. The time history speckle pattern, a THSP image, is an approach to analyze, which allows a summary to represent the activity monitored. THSP adoption has compelled the research to evaluate the information and the reliability of its inner pattern. This study presents a statistical approach to analyze the data using white noise tests and cross-spectrum analysis. The data analyzed was a set of THSP from animal sperm samples. The evaluation of white noise among lines was conducted using the Fischer test over eight THSP and the cross-spectral approach has been conducted by comparing the information in each THSP. The results presented that the THSP of the sperm did not behave as a white noise in a global evaluation, and specifically in the Gaussian white noise test over 4096 lines; only six lines presented the behavior of a white noise pattern. The strong rejection of white noise test confirms that the THSP pattern allows reliable information. The results obtained with the cross-spectral analysis presented differences between lines within the same THSP, showing that the information of an inner pattern varies in relation to space, which is against the findings in literature.

CHARACTERIZING DYNAMIC SPECKLE TIME SERIES WITH THE HURST COEFFICIENT CONCEPT

We propose in this work a dynamic speckle descriptor based on a Hurst wavelet estimator. The dynamic speckle or biospeckle is a phenomenon produced by laser illumination of active materials, such as biological tissue or the drying process of paint. Dynamic speckle interferometry is a useful technique for assessing the time evolution of surfaces as also to segment the loci of different activity in living tissues. Considering previous biospeckle characterization based on the autocorrelation function and its relation with the Hurst coefficient, a wavelet-based estimator is proposed as a feature extraction of the dynamic speckle characteristic. Encouraging results of the descriptor performance are obtained via three different experiments: a time history of speckle pattern applied to the drying of painting, segmenting regions in whole field image applied to the viability test of a corn seed and also to the bruising in fruits.