Search results for "Images"
showing 10 items of 460 documents
Turbidity analysis in Sicilian coastal zones by means of remote sensing images and spectroradiometric measurements
2009
Water turbidity has a wide range of variability both spatially and temporally. Rivers transport sediments to the river mouth following a seasonal behaviour and occasionally during flood events (Doxaran et al., 2006; Pribble et al., 2001). Once in the sea, sediments are spatially driven by currents, and re-suspended by waves from the bottom, changing water turbidity in the tidal and sub-tidal zones (Cloern et al., 1989; Uncles et al., 2002; Wolanski & Spagnol, 2003). Moreover human activities such as transport and dredging occasionally and locally influence turbidity magnitude and distribution (Schoellhamer, 1996). In recent years the pollution of the maritime environment suggests that only …
Graph-based minimal path tracking in the skeleton of the retinal vascular network
2012
This paper presents a semi-automatic framework for minimal path tracking in the skeleton of the retinal vascular network. The method is based on the graph structure of the vessel network. The vascular network is represented based on the skeleton of the available segmented vessels and using an undirected graph. Significant points on the skeleton are considered nodes of the graph, while the edge of the graph is represented by the vessel segment linking two neighboring nodes. The graph is represented then in the form of a connectivity matrix, using a novel method for defining vertex connectivity. Dijkstra and Floyd-Warshall algorithms are applied for detection of minimal paths within the graph…
Browser independent content based image resizing for liquid web layouts
2010
A typical problem for webdesigners is to realize pages that can be potentially accessed from a number of display devices with different screen sizes and resolutions. Liquid layouts can help for this purpose. However, they can not typically be applied to images, which need to be rescaled or deformed. In both cases usability could be deteriorated. Content-aware image resizing techniques can help for this goal by rescaling the images to the desired width while preserving important image structures. This paper presents a content-aware resizing technique which can be seamlessly integrated into web pages without any effort from the user. The results from the system application prove its effective…
Physical Metaphor for Streaming Media Retargeting
2014
We here introduce an image/video retargeting method that operates arbitrary aspect ratios resizing achieved in real-time performances. Most of the literature retargeting approaches sacrifice real-time performances in behalf of quality. On the other hand, existing fast methods provide arguable results. We can obtain a valuable trade-off between effectiveness and efficiency. The method named Spring Simulation Retargeting (SSR) is mainly based on a physical springs-based simulation. The media are assumed as flexible objects composed of particles and springs with different local stiffness properties, related to the visual importance of the content. The variation of the object size generates ela…
Continuous hand openness detection using a Kinect-like device
2014
This paper presents a novel method to reproduce in real time the opening and closing gestures of a human hand, animating a three-dimensional model of it. In other works, this result can be achieved by mapping a set of significant points of a real hand on the corresponding points of the model to animate. We propose an alternative way to produce the same effect without mapping points, but using a level-based estimation of the degree of opening of the hand. The experiments have been executed using Microsoft KinectTM, but the method would work on any other Kinect-like devices (as defined herein). The results obtained are particularly encouraging and demonstrate real-time performance of the syst…
Multi-modal Medical Image Registration by Local Affine Transformations
2018
Image registration is the process of finding the geometric transformation that, applied to the floating image, gives the registered image with the highest similarity to the reference image. Registering a pair of images involves the definition of a similarity function in terms of the parameters of the geometric transformation that allows the registration. This paper proposes to register a pair of images by iteratively maximizing the empirical mutual information through coordinate gradient descent. Hence, the registered image is obtained by applying a sequence of local affine transformations. Rather than adopting a uniformly spaced grid to select image blocks to locally register, as done by s…
Noise Filtering Using Edge-Driven Adaptive Anisotropic Diffusion
2008
This paper presents a method aimed to noise removal in MRI (Magnetic Resonance Imaging). We propose an improvement of Perona and Malik's anisotropic diffusion filter. In our schema, the diffusion equation of the filter has been modified to take into account the edges direction, This allows the filter to blur uniform areas, while it better preserves the edges. Both quantitative and qualitative evaluation is presented and the results are compared with other methods.
Restoration of Digitized Damaged Photos using Bit-Plane Slicing
2007
Digital image restoration aims to recover damaged zones of a digital image, using surrounding information. In this paper we propose a novel approach, based on bit-plane slicing decomposition, with the purpose to make information analysis and reconstruction process easy, fast and effective. Tests have been made on digitized damaged old photos to restore several classes of typical defects in old photographic prints.
An Explorable Immersive Panorama
2012
The immersive panoramas are widely used to provide virtual tours of real scene. Their use covers a wide field of applications: art, industry, space research, topography, forensic investigation and all those systems requiring the exploration of a virtual environment which simulates a real one. Often sophisticated devices are used to perform the panorama acquisition. In this paper, we present an image based immersive panorama requiring low cost devices for the acquisition task and provides an innovative human-computer interaction approach. Many panoramic images of the same location are captured. The visualization system changes the panorama in a transparent way with respect to the user intera…
PHOTOGRAMMETRY NOW AND THEN - FROM HAND-CRAFTED TO DEEP-LEARNING TIE POINTS
2022
Abstract. Historical images provide a valuable source of information exploited by several kinds of applications, such as the monitoring of cities and territories, the reconstruction of destroyed buildings, and are increasingly being shared for cultural promotion projects through virtual reality or augmented reality applications. Finding reliable and accurate matches between historical and present images is a fundamental step for such tasks since they require to co-register the present 3D scene with the past one. Classical image matching solutions are sensitive to strong radiometric variations within the images, which are particularly relevant in these multi-temporal contexts due to differen…