Search results for "Image."

A new method for morphometric analysis of opal phytoliths from plants.

2014

Micro-morphometry has substantially gained ground in the field of phytolith analysis, but the comparability of results is limited due to the use of different methods. This paper presents a new, user-friendly method based on open-source software (FIJI) that is proposed as a step towards the introduction of a standard method. After obtaining a mask of a phytolith by making a digital drawing, 27 commonly used variables of size and shape are measured automatically. This method is not only useful for phytolith analysis, but may also be used for other fields of morphometric research. Users can furthermore customize the software tool when additional variables are required.

Temperature-induced microstructural changes in shells of laboratory-grown Arctica islandica (Bivalvia).

2021

Bivalve shells are increasingly used as archives for high-resolution paleoclimate analyses. However, there is still an urgent need for quantitative temperature proxies that work without knowledge of the water chemistry–as is required for δ18O-based paleothermometry–and can better withstand diagenetic overprint. Recently, microstructural properties have been identified as a potential candidate fulfilling these requirements. So far, only few different microstructure categories (nacreous, prismatic and crossed-lamellar) of some short-lived species have been studied in detail, and in all such studies, the size and/or shape of individual biomineral units was found to increase with water temperat…

PREPARATION AND CHARACTERIZATION OF BIOPOLYMERIC POROUS STRUCTURES FOR ADVANCED APPLICATIONS

Porous biopolymers received an increasing academic and industrial interest finding application in several fields such as tissue engineering, bioprocess intensification and waste removal. Tissue engineering combines the knowledge of materials science and bioengineering in order to develop structures able to substitute and restore the normal function of injured or diseased tissues. In this context, polymeric 3D or 2D scaffolds are widely investigated as temporary cell guidance during the tissue restore. Porous biomaterials can offer a versatile and cost effective way for immobilization of filamentous microorganisms in submerged fermentation processes for the production of biologically active …

INTEGRAL/RXTE Observations of Cygnus X-1

2003

We present first results from contemporaneous observations of Cygnus X-1 with INTEGRAL and RXTE, made during INTEGRAL's performance verification phase in 2002 November and December. Consistent with earlier results, the 3-250 keV data are well described by Comptonization spectra from a Compton corona with a temperature of kT~50-90 keV and an optical depth of tau~1.0-1.3 plus reflection from a cold or mildly ionized slab with a covering factor of Omega/2pi~0.2-0.3. A soft excess below 10 keV, interpreted as emission from the accretion disk, is seen to decrease during the 1.5 months spanned by our observations. Our results indicate a remarkable consistency among the independently calibrated de…

A Robust Generic Method for Grid Detection in White Light Microscopy Malassez Blade Images in the Context of Cell Counting

2015

AbstractIn biology, cell counting is a primary measurement and it is usually performed manually using hemocytometers such as Malassez blades. This work is tedious and can be automated using image processing. An algorithm based on Fourier transform filtering and the Hough transform was developed for Malassez blade grid extraction. This facilitates cell segmentation and counting within the grid. For the present work, a set of 137 images with high variability was processed. Grids were accurately detected in 98% of these images.

On the use of Denoising Autoencoders and Deep Convolutional Adversarial Networks for Automated Removal of Date Stamps

2019

Master's thesis Information- and communication technology IKT590 - University of Agder 2019 This thesis investigates to what extent the deep learning models such as DenoisingAutoencoder (DAE) and Deep Convolution General Adversarial Net (DCGAN)automate the removal of the date stamps from images with high resolution whilepreserving the rest of the images. Both DAE and DCGAN algorithms are im-plemented with Convolutional Neural Networks (CNN). The DAE algorithm canperform this task with entirely satisfactory results. The DAE can reconstruct theoriginal images from corrupted inputs with date stamps. While DCGAN deliverspoor yet interesting results. The images generated by the DCGAN are quite d…

Blind deconvolution using TV regularization and Bregman iteration

2005

In this paper we formulate a new time dependent model for blind deconvolution based on a constrained variational model that uses the sum of the total variation norms of the signal and the kernel as a regularizing functional. We incorporate mass conservation and the nonnegativity of the kernel and the signal as additional constraints. We apply the idea of Bregman iterative regularization, first used for image restoration by Osher and colleagues [S.J. Osher, M. Burger, D. Goldfarb, J.J. Xu, and W. Yin, An iterated regularization method for total variation based on image restoration, UCLA CAM Report, 04-13, (2004)]. to recover finer scales. We also present an analytical study of the model disc…

Free-depths reconstruction with synthetic impulse response in integral imaging

2015

Integral Imaging provides spatial and angular information of three-dimensional (3D) objects, which can be used both for 3D display and for computational post-processing purposes. In order to recover the depth information from an integral image, several algorithms have been developed. In this paper, we propose a new free depth synthesis and reconstruction method based on the two-dimensional (2D) deconvolution between the integral image and a simplified version of the periodic impulse response function (IRF) of the system. The period of the IRF depends directly on the axial position within the object space. Then, we can retrieve the depth information by performing the deconvolution with compu…

A time evolution model for total-variation based blind deconvolution

2007

Departamento Matematica Aplicada, Universidad de Valencia, Burjassot 46100, Spain.We propose a time evolution model for total-variation based blind deconvolution consisting of two evolution equations evolv-ing the signal by means of a nonlinear scale space method and the kernel by using a diffusion equation starting from the zerosignal and a delta function respectively. A preliminary numerical test consisting of blind deconvolution of a noiseless blurredimage is presented.

Sparse Deconvolution Using Support Vector Machines

2008

Sparse deconvolution is a classical subject in digital signal processing, having many practical applications. Support vector machine (SVM) algorithms show a series of characteristics, such as sparse solutions and implicit regularization, which make them attractive for solving sparse deconvolution problems. Here, a sparse deconvolution algorithm based on the SVM framework for signal processing is presented and analyzed, including comparative evaluations of its performance from the points of view of estimation and detection capabilities, and of robustness with respect to non-Gaussian additive noise. Publicado