Nikolaos D. Doulamis

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A framework for video content representation is proposed in this paper for extracting limited, but meaningful, information of video data directly from MPEG compressed domain. First, the traditional frame-based representation is transformed to a feature-based one. Then, all features are gathered together using a fuzzy formulation and extraction of several(More)
Grid technology is widely emerging. Still, there is an eminent shortage of real Grid users, mostly due to the lack of a " critical mass " of widely deployed and reliable higher-level Grid services, tailored to application needs. The GridLab project aims to provide fundamentally new capabilities for applications to exploit the power of Grid computing, thus(More)
A novel approach is presented in this paper for improving the performance of neural-network classifiers in image recognition, segmentation, or coding applications, based on a retraining procedure at the user level. The procedure includes: 1) a training algorithm for adapting the network weights to the current condition; 2) a maximum a posteriori (MAP)(More)
— An adaptive algorithm for extracting foreground objects from background in videophone or videoconference applications is presented in this paper. The algorithm uses a neural network architecture that classifies the video frames in regions-of-interest (ROI) and non-ROI areas, also being able to automatically adapt its performance to scene changes. The(More)
This paper performs issues relative to modeling of VBR MPEG coded video sources over ATM B-ISDN networks. Firstly, we analyse the statistical characteristics of the three types of frames, which the MPEG algorithm generates, and we study their autocovariance and probability density functions. Based on the data analysis, we propose two new source models which(More)
In this paper, an optimal relevance algorithm is proposed, which adapts the response of a content-based image retrieval (CBIR) system to the user's information needs. In particular, the importance of each descriptor to the similarity measure of the system is estimated so that the correlation between the query image and all images marked by the user as(More)