Viewpoint switching in multiview videos using SP-frames

The distinguishing feature of multiview video lies in the interactivity, which allows users to select their favourite viewpoint. It switches bitstream at a particular view when necessary instead of transmitting all the views. The new SP-frame in H.264 is originally developed for multiple bit-rate streaming with the support of seamless switching. The SP-frame can also be directly employed in the viewpoint switching of multiview videos. Notwithstanding the guarantee of seamless switching using SP-frames, the cost is the bulky size of secondary SP-frames. This induces a significant amount of additional space or bandwidth for storage or transmission, especially for the multiview scenario. For this reason, a new motion estimation and compensation technique operating in the quantized transform (QDCT) domain is designed for coding secondary SP-frame in this paper. Our proposed work aims at keeping the secondary SP-frames as small as possible without affecting the size of primary SP-frames by incorporating QDCT-domain motion estimation and compensation in the secondary SP-frame coding. Simulation results show that the size of secondary SP-frames can be reduced remarkably in viewpoint switching. Index Terms — Multiview, viewpoint switching, SP-frame, QDCT-domain, motion estimatio

Fios e desafios da atenção à saúde da criança no estado do Espírito Santo: análise da mortalidade de zero a cinco anos com gestores do Programa Estadual de Saúde da Mulher e da Criança

Trata-se de um estudo de abordagem qualitativa que objetivou discutir a mortalidade de zero a cinco anos, no estado do Espírito Santo, no lapso de agosto de 2011 a agosto de 2012, a partir de matérias veiculadas por um jornal diário da mídia impressa de grande circulação, a saber A Gazeta. As referidas matérias constituíram uma hemeroteca que subsidiou a criação de um painel reprográfico. Os sujeitos da investigação foram os técnicos que compõem a equipe da Coordenação do Programa Estadual de Saúde da Mulher e da Criança, e a produção do material de estudo se deu a partir da análise de um grupo focal, com roteiro semiestruturado, tendo como partida a análise de uma cópia do painel contendo todas as máterias. Todo o material foi gravado e filmado. A Análise Institutucional foi a baliza norteadora de toda a elaboração e descrição do estudo. Conforme preconiza este quadro teórico proposto por Lourau, a etapa final do projeto constituiu-se em uma restituição concreta parte do procedimento científico, tratando-se da discussão das produções na pesquisa com os interessados, de modo a possibilitar a sua interferência direta neste processo. O estudo demonstrou que os sujeitos, a partir do dispositivo analisador natural, a morte de crianças menores de cinco anos, conseguiram fazer uma reflexão sobre o quanto é necessário buscar uma interlocução com os demais setores e perceber que a análise institucional, com sua potência de provocar a autoanálise e a autogestão, proporcionou-lhes uma possibilidade de repensar seus processos de trabalho na atenção à saúde da criança

A New Motion Vector Composition Algorithm for H.264 Multiple Reference Frame Motion Estimation

Multiple reference frame motion estimation (MRF-ME) is an important tool in H.264 to improve coding efficiency. However, it penalizes the encoder in computational complexity. When the number of reference frames increases, the required computation expands proportionally. Therefore, various motion vector composition algorithms have been proposed to reduce the computational complexity of the encoder. However, it is found that they only perform well in a limited range of reference frames. In this paper, a new composition algorithm is proposed to compose a resultant motion vector from a set of candidate motion vectors. The proposed algorithm is especially suited for temporally remote reference frames in MRF-ME. Compared with existing algorithms, experimental results show that the new algorithm can deliver a remarkable improvement on the rate-distortion performance.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Poster session: Image, Video, and Multimedia Signal Processing 2 (6 October 2009)

Mode Information Guided CNN for Quality Enhancement of Screen Content Coding

Video quality enhancement methods are of great significance in reducing the artifacts of decoded videos in the High Efficiency Video Coding (HEVC). However, existing methods mainly focus on improving the quality of natural sequences, not for screen content sequences that have drawn more attention than ever due to the demands of remote desktops and online meetings. Different from the natural sequences encoded by HEVC, the screen content sequences are encoded by Screen Content Coding (SCC), an extension tool of HEVC. Therefore, we propose a Mode Information guided CNN (MICNN) to further improve the quality of screen content sequences at the decoder side. To exploit the characteristics of the screen content sequences, we extract the mode information from the bitstream as the input of MICNN. Furthermore, due to the limited number of screen content sequences, we establish a large-scale dataset to train and validate our MICNN. Experimental results show that our proposed MICNN can achieve 3.41% BD-rate saving on average. In addition, our MICNN method consumes acceptable computational time compared with the other video quality enhancement methods