Search results for "segmentation"
showing 10 items of 674 documents
Signal Restoration via a Splitting Approach
2012
International audience; In the present study, a novel signal restoration method from noisy data samples is presented and is termed as "signal split (SSplit)" approach. The new method utilizes Stein unbiased risk estimate estimator to split the signal, the Lipschitz exponents to identify noise elements and a heuristic approach for the signal reconstruction. However, unlike many noise removal techniques, the present method works only in the non-orthogonal domain. Signal restoration was performed on each individual part by finding the best compromise between the data samples and the smoothing criteria. Statistical results are quite promising and suggest better performance than the conventional…
An application of neural networks to natural scene segmentation
2006
This paper introduces a method for low level image segmentation. Pixels of the image are classified corresponding to their chromatic features.
Quantifizierung von Atelektasen bei kontrollierter Beatmung: Spiral-CT versus dynamische Einzelschicht-CT
2004
Ziel: Dynamische CT-Untersuchungen (dCT) erlauben die Darstellung und Quantifizierung ventilierter Lungenflache und Atelektasenbildung wahrend kontinuierlicher Beatmung. Diese Studie vergleicht eine quantitative Auswertung einer infrakarinalen dCT-Einzelschicht mit der einer Spiral-CT der gesamten Lunge, um zu untersuchen, ob eine dynamisch gemessene Einzelschicht bezuglich der intrapulmonalen Atelektasenverteilung reprasentativ fur die Gesamtlunge ist. Material und Methoden: An 8 gesunden Schweinen erfolgte eine dCT (Schichtdicke 1 mm, zeitliches Inkrement 100 ms) wahrend kontinuierlicher Beatmung, gefolgt von einer Spiral-CT der gesamten Lunge (Schichtdicke 2 mm; Pitch 1,5; Inkrement 2 m…
Computational Analysis Workshop: Comparing Four Approaches to Melodic Analysis
2009
We compare four computational approaches of melodic analysis according to diverse approach aspects: input type (monophonic or polyphonic), pattern identification type (strict or similar), analysis segmentation, aim of approach, motivic pattern representation, and type of result representations. The considered four computational approaches are the following: a similarity neighbourhood approach by Adiloglu (Adiloglu and Obermayer 2006a, b), a multiple viewpoint representation and discovery approach by Anagnostopoulou (Anagnostopoulou, Share and Conklin 2006), a topological approach by Buteau (2005), and an approach based on multidimensional closed pattern mining by Lartillot (Lartillot and To…
Leaping across Modalities: Speed Regulation Messages in Audio and Tactile Domains
2010
This study examines three design bases for speed regulation messages by testing their ability to function across modalities. Two of the design bases utilise a method originally intended for sound design and the third uses a method meant for tactile feedback. According to the experimental results, all designs communicate the intended meanings similarly in audio and tactile domains. It was also found that melodic (frequency changes) and rhythmic (segmentation) features of stimuli function differently for each type of message.
Adaptive surface compression with geometric wavelets.
2008
The recent advances in computer graphics and digitization allow access to an ever finer three-dimensional modelling of the world. The critical challenges with 3D models lie in their transmission and rendering, which must fit the heterogeneity of the end resources (network bandwidth, display terminals . . . ). In this context, this thesis investigates the progressive compression and transmission of 3D models, based on multiresolution analysis, to provide a scalable representation of these geometric models. This work is part of "CoSurf", a collaborative research project involving LIRIS laboratory and France Télécom R&D in Rennes. The proposed hierarchical compression method is based on a wave…
Expression of en and wg in the embryonic head and brain of Drosophila indicates a refolded band of seven segment remnants
1992
ABSTRACT Based on the expression pattern of the segment polarity genes engrailed and wingless during the embryonic development of the larval head, we found evidence that the head of Drosophila consists of remnants of seven segments (4 pregnathal and 3 gnathal) all of which contribute cells to neuromeres in the central nervous system. Until completion of germ band retraction, the four pregnathal segment remnants and their corresponding neuromeres become arranged in an S-shape. We discuss published evidence for seven head segments and morphogenetic movements during head formation in various insects (and crustaceans).
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…
Microaneurysms detection with the radon cliff operator in retinal fundus images
2010
ABSTRACT Diabetic Retinopathy (DR) is one of the leading causes of blindness in the industrialized world. Early detection is thekey in providing effective treatment. However, the current number of trained eye care specialists is inadequate to screenthe increasing number of diabetic patients. In recent years, automated and semi-automated systems to detect DR withcolor fundus images have been developedwith encouraging,but not fully satisfactory results. In this study we present theinitial results of a new techniquefor the detection and localization of microaneurysms,an early sign of DR. The algorithmis based on three steps: candidates selection, the actual microaneurysms detection and a Þnal …
A Survey on Microaneurysms Detection in Color Fundus Images
2020
Early Detection of Microaneurysms (MA) plays a vital role in preventing the blindness caused by diabetic retinopathy (DR). DR is preventable yet a serious diabetic problem. Treatment at an earlier stage reduces the risk of blindness. Microaneurysm is the first sign of DR found in fundus images while doing screening. Detection of MA is a challenging task mainly because of its size. MA appears as a tiny red spot ranging from 15µm to 60µm size. The most common way to detect the MA from a colour fundus image is by classification/segmentation through machine learning and deep learning approaches. The FROC-based performance evaluation shows that the existing methods can reach only up to 80% of se…