Search results for "Segmentation"
showing 10 items of 674 documents
A simple and efficient face detection algorithm for video database applications
2000
The objective of this work is to provide a simple and yet efficient tool to detect human faces in video sequences. This information can be very useful for many applications such as video indexing and video browsing. In particular the paper focuses on the significant improvements made to our face detection algorithm presented by Albiol, Bouman and Delp (see IEEE Int. Conference on Image Processing, Kobe, Japan, 1999). Specifically, a novel approach to retrieve skin-like homogeneous regions is presented, which is later used to retrieve face images. Good results have been obtained for a large variety of video sequences. Peer Reviewed
Image segmentation to evaluate islets of langherans
2008
This contribution deals with an unsupervised system to process digital photomicrographs in order to locate and analyze islets of Langherans in human pancreases. The experiment has been conducted on real data and, though we are still going to complete the evaluation of the whole method, we expect to define a set of proper features (e.g. area, perimeter, fractal dimension, shape complexity, texture and entropy) useful for a fast and reliable counting of healthy cells. In particular, this research aims to measure the advisability of a possible implantation in patients affected by type I diabetes mellitus
Studies of methods and tools for the really mixed visual coherence applied to the patrimony
2013
The work described in this report has as a target the mixed reality device ray-on, developed by the on-situ company. This device, dedicated to cultural heritage and specifically architectural heritage, is meant to be installed on-site and shows the user an uchronic view of its surroundings. As the chosen stance is to display photo-realistic images, two trails were followed: the improvement of the real-virtual merging by reproducing accurately the real lighting on the virtual objects, and the development of a real-time segmentation method which is resilient to lighting changes.Regarding lighting reproduction, an image-based rendering method is used in addition to a high dynamic range capture…
Dissecting and Reassembling Color Correction Algorithms for Image Stitching
2018
This paper introduces a new compositional framework for classifying color correction methods according to their two main computational units. The framework was used to dissect fifteen among the best color correction algorithms and the computational units so derived, with the addition of four new units specifically designed for this work, were then reassembled in a combinatorial way to originate about one hundred distinct color correction methods, most of which never considered before. The above color correction methods were tested on three different existing datasets, including both real and artificial color transformations, plus a novel dataset of real image pairs categorized according to …
Textile and tile pattern design automatic cataloguing using detection of the plane symmetry group
2004
We present an integrated management system of pattern design for the textile and tile industries providing automatic cataloguing capabilities based on the application of the scientific theory of symmetry groups. To do this, a process of analysis is performed which starts from an initial image of the decorative element, which in turn is subjected to a number of segmentation and labelling operators that allow to detect the objects present in the image. These objects are vectorized, compared, and their isometries obtained; subsequently they are grouped and the isometries of the groups of objects detected. Finally, a composition analysis is carried out that, on the basis of the repetitions and …
Supershape Recovery from 3D Data Sets
2006
In this paper, we apply supershapes and R-functions to surface recovery from 3D data sets. Individual supershapes are separately recovered from a segmented mesh. R-functions are used to perform Boolean operations between the reconstructed parts to obtain a single implicit equation of the reconstructed object that is used to define a global error reconstruction function. We present surface recovery results ranging from single synthetic data to real complex objects involving the composition of several supershapes and holes.
Evolving Tree Algorithm Modifications
2007
There are many variants of the original self-organizing neural map algorithm proposed by Kohonen. One of the most recent is the Evolving Tree, a tree-shaped self-organizing network which has many interesting characteristics. This network builds a tree structure splitting the input dataset during learning. This paper presents a speed-up modification of the original training algorithm useful when the Evolving Tree network is used with complex data as images or video. After a measurement of the effectiveness an application of the modified algorithm in image segmentation is presented.
<title>Combining multiple image descriptions for browsing and retrieval</title>
2000
Retrieving images form large collections using image content is an important problem, in this multimedia age. A quick content-based visual access to the stored image is capital for efficient navigation through image collections. In this paper we introduce several techniques which characterize color homogeneous object and their spatial relationships for efficient content-based image retrieval. We present a region growing technique for efficient color homogeneous objects segmentation and extend the 2D string to an accurate description of spatial information and relationships. In order to improve content-based image retrieval, our method emphasized several objectives, such as: automated extrac…
A non-parametric Scale-based Corner Detector
2008
This paper introduces a new Harris-affine corner detector algorithm, that does not need parameters to locate corners in images, given an observation scale. Standard detectors require to fine tune the values of parameters which strictly depend on the particular input image. A quantitative comparison between our implementation and a standard Harris-affine implementation provides good results, showing that the proposed methodology is robust and accurate. The benchmark consists of public images used in literature for feature detection.
Exploring the tourism markets’ convergence hypothesis in Italy
2020
This article aims at investigating the tourism markets’ convergence hypothesis across Italy’s 20 major source markets. To reach our goal, we use monthly data of tourist arrivals and overnights over the period 2008–2018 and the time-varying factor model developed by Phillips and Sul (2007, 2009). Our findings suggest the absence of full (absolute) convergence, leading us to accept the hypothesis of club convergence. We show that the traditionally more important source markets have a tendency to persist, while Asian countries show heterogeneous behaviour. Furthermore, the relative decline in the contribution to total arrivals and overnights of several international source markets calls for a…