Search results for "Image Analysi"
showing 10 items of 173 documents
A fuzzy approach to the evaluation of image complexity
2009
The inherently multidimensional problem of evaluating the complexity of an image is of a certain relevance in both computer science and cognitive psychology. Computer scientists usually analyze spatial dimensions in order to deal with automatic vision problems, such as feature extraction. Psychologists seem more interested in the temporal dimension of complexity, as a means to explore attentional models. Is it possible to define, by merging both approaches, a more general index of visual complexity? The aim of this paper is the definition of objective measures of image complexity that fits with the so named perceived time. Towards the end we have defined a fuzzy mathematical model of visual…
Automated segmentation and description of the internal morphology of human permanent teeth by means of micro-CT
2020
High-resolution micro-computed tomography is a powerful tool to analyze and visualize the internal morphology of human permanent teeth. It is increasingly used for investigation of epidemiological questions to provide the dentist with the necessary information required for successful endodontic treatment. The aim of the present paper was to propose an image processing method to automate parts of the work needed to fully describe the internal morphology of human permanent teeth. One hundred and four human teeth were scanned on a high-resolution micro-CT scanner using an automatic specimen changer. Python code in a Jupyter notebook was used to verify and process the scans, prepare the dataset…
Medical Imaging Applications: Three Case Studies
2006
Reliable Detection and Smart Deletion of Malassez Counting Chamber Grid in Microscopic White Light Images for Microbiological Applications
2015
AbstractIn biology, hemocytometers such as Malassez slides are widely used and are effective tools for counting cells manually. In a previous work, a robust algorithm was developed for grid extraction in Malassez slide images. This algorithm was evaluated on a set of 135 images and grids were accurately detected in most cases, but there remained failures for the most difficult images. In this work, we present an optimization of this algorithm that allows for 100% grid detection and a 25% improvement in grid positioning accuracy. These improvements make the algorithm fully reliable for grid detection. This optimization also allows complete erasing of the grid without altering the cells, whic…
Automatic Assessment of Depression Based on Visual Cues: A Systematic Review
2019
International audience; Automatic depression assessment based on visual cues is a rapidly growing research domain. The present exhaustive review of existing approaches as reported in over sixty publications during the last ten years focuses on image processing and machine learning algorithms. Visual manifestations of depression, various procedures used for data collection, and existing datasets are summarized. The review outlines methods and algorithms for visual feature extraction, dimensionality reduction, decision methods for classification and regression approaches, as well as different fusion strategies. A quantitative meta-analysis of reported results, relying on performance metrics r…
A genetic algorithm for scratch removal in static images
2002
This paper investigates the removal of line scratches from old moving pictures and gives a twofold contribution. First, it presents a simple technique for detecting the scratches, based on an analysis of the statistics of the grey levels. Second, the scratch removal is approached as an optimisation problem, which is solved by using a genetic algorithm. The method can be classified as a static approach, as it works independently on each single frame of the sequence. It does not require any a-priori knowledge of the absolute position of the scratch, nor an external starting population of chromosomes for the genetic algorithm. The central column of the line scratch once detected is changed wit…
Toward an Integrated System for Surveillance and Behaviour Analysis of Groups and People
2013
Security and INTelligence SYStem is an Italian research project which aims to create an integrated system for the analysis of multi-modal data sources (text, images, video, audio), to assist operators in homeland security applications. Within this project the Scientific Research Unit of the University of Palermo is responsible of the image and video analysis activity. The SRU of Palermo developed a web service based architecture that provides image and video analysis capabilities to the integrated analysis system. The developed architecture uses both state of the art techniques, adapted to cope with the particular problem at hand, and new algorithms to provide the following services: image …
TURF-BOX: an active lighting multispectral imaging system with led VIS-NIR sources for monitoring of vegetated surfaces
2021
A microcontroller driven system suitable to monitor soil and low vegetation is described. A radiometrically pre-calibrated imaging camera driven by a microcontroller is contained in a light-tight box aiming at an actively illuminated target surface area of 50×38 cm, using LED sources with different emission wavelengths (blue, green, red and infrared). The adopted arrangement allows measurements independent from local lighting conditions and from the in situ, per-session calibrations necessary with the conventional instrumentation adopted for field measurements. Sequential lighting of the target surface with the monochromatic LED sources allows capturing multispectral images at a relatively …
Sedimentation of halloysite nanotubes from different deposits in aqueous media at variable ionic strengths
2019
Abstract Halloysite clay is a natural nanomaterial that is attracting a growing interest in colloidal science. The halloysite aqueous dispersion stability is a key aspect for the configuration of a purification protocol as well as to establish the durability of a formulation. A physico-chemical study demonstrated the role of ionic strength and nanotube characteristic sizes on the sedimentation behavior. We highlighted the importance of the electrostatic repulsions exercised between the particles in the settling process. A protocol for image analysis has been proposed to provide robust information from time resolved optical images on the suspensions. In conclusion, we managed to correlate mi…
MAPPATURA DEL DISORDINE NON LINEARE MEDIANTE INTERAZIONE PARAMETRICA A TRE ONDE
2010
We introduce a simple approach for characterizing the ferroelectric domain distribution in bulk quadratic crystals. The approach is demonstrated in a lithium tantalate sample with periodic electric field poling and random mark-to-space ratio.