Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Costs and Advantages of Object-Based Image Coding with Shape-Adaptive Wavelet Transform | Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2007 Article ID 78323 13 pages doi 2007 78323 Research Article Costs and Advantages of Object-Based Image Coding with Shape-Adaptive Wavelet Transform Marco Cagnazzo Sara Parrilli Giovanni Poggi and Luisa Verdoliva Dipartimento di Ingegneria Elettronica e delle Telecomunicazioni Universita Federico II di Napoli Via Claudio 21 80125 Napoli Italy Received 19 August 2006 Revised 27 November 2006 Accepted 5 January 2007 Recommended by Beatrice Pesquet-Popescu Object-based image coding is drawing a great attention for the many opportunities it offers to high-level applications. In terms of rate-distortion performance however its value is still uncertain because the gains provided by an accurate image segmentation are balanced by the inefficiency of coding objects of arbitrary shape with losses that depend on both the coding scheme and the object geometry. This work aims at measuring rate-distortion costs and gains for a wavelet-based shape-adaptive encoder similar to the shape-adaptive texture coder adopted in MPEG-4. The analysis of the rate-distortion curves obtained in several experiments provides insight about what performance gains and losses can be expected in various operative conditions and shows the potential of such an approach for image coding. Copyright 2007 Marco Cagnazzo et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Object-based image coding is an increasingly active area of research dating back to early works on second generation coding techniques 1 and gaining momentum more recently thanks to the driving force of the MPEG-4 video coding standard 2 . The major conceptual reason for object-based coding is that images are naturally composed by objects and the usual pixel-level .
