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 Content-Aware Scalability-Type Selection for Rate Adaptation of Scalable Video | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 10236 11 pages doi 2007 10236 Research Article Content-Aware Scalability-Type Selection for Rate Adaptation of Scalable Video Emrah Akyol 1 A. Murat Tekalp 2 and M. Reha Civanlar3 1 Departmet of Electrical Engineering Henry Samuel School of Engineering and Applied Science University of California . Box 951594 Los Angeles CA 90095-1594 USA 2 Department of Electrical and Computer Engineering College of Engineering Koc University 34450 Sariyer Istanbul Turkey 3 DoCoMo USA Labs Palo Alto CA 94304-1201 USA Received 4 October 2006 Revised 31 December 2006 Accepted 14 February 2007 Recommended by Chia-Wen Lin Scalable video coders provide different scaling options such as temporal spatial and SNR scalabilities where rate reduction by discarding enhancement layers of different scalability-type results in different kinds and or levels of visual distortion depend on the content and bitrate. This dependency between scalability type video content and bitrate is not well investigated in the literature. To this effect we first propose an objective function that quantifies flatness blockiness blurriness and temporal jerkiness artifacts caused by rate reduction by spatial size frame rate and quantization parameter scaling. Next the weights of this objective function are determined for different content shot types and different bitrates using a training procedure with subjective evaluation. Finally a method is proposed for choosing the best scaling type for each temporal segment that results in minimum visual distortion according to this objective function given the content type of temporal segments. Two subjective tests have been performed to validate the proposed procedure for content-aware selection of the best scalability type on soccer videos. Soccer videos scaled from 600 kbps to 100 kbps by the proposed content-aware selection of scalability type have been found
