An enhanced random walk algorithm for delineation of head and neck cancers in PET studies
An algorithm for delineating complex head and neck cancers in positron emission tomography (PET) images is presented in this article. An enhanced random walk (RW) algorithm with automatic seed detection is proposed and used to make the segmentation process feasible in the event of inhomogeneous lesions with bifurcations. In addition, an adaptive probability threshold and a k-means based clustering technique have been integrated in the proposed enhanced RW algorithm. The new threshold is capable of following the intensity changes between adjacent slices along the whole cancer volume, leading to an operator-independent algorithm. Validation experiments were first conducted on phantom studies:…
Toward an Integrated System for Surveillance and Behaviour Analysis of Groups and People
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 …
Optic disc positioning and blood vessels extraction on eye fundus
This paper presents two methods aimed to the optic disc positioning on the retinal images. The first is based on a template of the entire image, while the second is based on the retinal vascularisation. For this second task, also a vessel extraction method is provided. Both the algorithm have been tested on test images of the Drive Database.
An automatic method for metabolic evaluation of gamma knife treatments
Lesion volume delineation of Positron Emission Tomography images is challenging because of the low spatial resolution and high noise level. Aim of this work is the development of an operator independent segmentation method of metabolic images. For this purpose, an algorithm for the biological tumor volume delineation based on random walks on graphs has been used. Twenty-four cerebral tumors are segmented to evaluate the functional follow-up after Gamma Knife radiotherapy treatment. Experimental results show that the segmentation algorithm is accurate and has real-time performance. In addition, it can reflect metabolic changes useful to evaluate radiotherapy response in treated patients.
Automatic aesthetic photo composition
A proper aesthetic composition of photographic content does result in an actual emotional response from the watcher. In this work we propose a fully automatic computational approach to photo composi- tion. This method takes into account well-known and widely adopted aesthetic guidelines relative to picture content as a mean for guiding an optimization framework. The resulting composition is produced as the optimal combination of cropping and retargeting. The effectiveness of the results achieved by the method are tested and evaluated with several of experiments.
Exploiting Visual Saliency Algorithms for Object-Based Attention: A New Color and Scale-Based Approach
Visual Saliency aims to detect the most important regions of an image from a perceptual point of view. More in detail, the goal of Visual Saliency is to build a Saliency Map revealing the salient subset of a given image by analyzing bottom-up and top-down factors of Visual Attention. In this paper we proposed a new method for Saliency detection based on colour and scale analysis, extending our previous work based on SIFT spatial density inspection. We conducted several experiments to study the relationships between saliency methods and the object attention processes and we collected experimental data by tracking the eye movements of thirty viewers in the first three seconds of observation o…
Browser independent content based image resizing for liquid web layouts
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…
Notice of Violation of IEEE Publication Principles: Distributed Multimedia Digital Libraries on Peer-to-Peer Networks
This paper presents an original approach to image sharing in large, distributed digital libraries, in which a user is able to interactively search interesting resources by means of content-based image retrieval techniques. The approach described here addresses the issues arising when the content is managed through a peer-to-peer architecture. In this case, the retrieval facilities are likely to be limited to queries based on unique identifiers or small sets of keywords, which may be quite inadequate, so we propose a novel algorithm for routing user queries that exploits compact representations of multimedia resources shared by each peer in order to dynamically adapt the network topology to …
Automatic image enhancement by picture fusion
This paper describes an automatic technique able to fuse different images of the same scene, acquired with different camera settings, in order to obtain an enhanced single representation of the interested. This allows to extend the functionalities (depth of field, dynamic range) of medium and low cost digital cameras. When Multi-Scale Decomposition (MSD) is used on differently focused images, magnification and blurring effects of lens focusing systems often compromise the final image with unpleasant artifacts. In our approach new techniques able to reduce these artifacts are introduced. Even if the algorithm has been essentially designed to extend depth of field it can be also used on multi…