Tag Archives: parallel computations

Experimental Studies on the Performance of Algorithms for CFA Interpolation

Iva Nikolova

Abstract: This paper deals with the challenging task of reconstructing a full three-color representation of color images captured by a single image sensor – CCD or CMOS, which samples the image according to a color filter array (CFA). The output images feature a certain kind of pattern in which every pixel has only single-color information. The process of modifying the raw image sensor data to obtain full RGB color information at each pixel is called demosaicing or CFA interpolation. Seven popular algorithms CFA interpolation are regarded. The results of timing performance analysis of their sequential implementations are presented and discussed. The performance speedup analysis and scalability tests with multithreading and CUDA-based GPU implementations are analyzed.
Keywords: Bayer pattern, CFA interpolation, GPU, Image sensors, Multithreading, Parallel computations, Performance and speedup analysis.

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Recognition of Astronomical Objects for Photometric and Astrometric Purposes Using Parallel Computations

Milena Lazarova, Irina Nikolova

Abstract:Parallel algorithmic model for astronomical objects recognition is suggested in the paper. The analyses are aimed to find all astronomical objects in an image,  to make photometric meas- urements and to build a catalog of the objects’ features that will be used  in  further  astrometric and/or photometric analyses. The suggested parallel computational model is based on data de- composition and uses a combination of parallel algorithmic  paradigms “master-slave”  and SPMD. The experimental results on a cluster of symmetric multiprocessors and the communication profiles show that the suggested parallel model scales well in respect to both the workload and the cluster size.

Key words: astronomical objects, astrometric and photometric analyses, parallel computations, message passing,  SPMD, manager-worker,  cluster

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