Rate control plays a major role in video coding and multimedia streaming. A well-designed rate control scheme should pursue both the objective quality and subjective quality. However, existing H.264 rate control algor...
详细信息
ISBN:
(纸本)9781605588407
Rate control plays a major role in video coding and multimedia streaming. A well-designed rate control scheme should pursue both the objective quality and subjective quality. However, existing H.264 rate control algorithms mainly aim at improving the objective quality without consideration the perception of human view system (HVS). In this paper, we propose a novel rate control algorithm based on local motion attention. The bits allocated to each frame are proportional to the local motion activity in it, and more bits are allocated to the frame with strong local motion attention. Experiment results show that our method not only enhances the coding quality in the frames with strong local motion attention but also reduces the temporal PSNR fluctuation across frames up to 22.15%. Copyright 2009 ACM.
The H.264 video coding standard adopts multiple reference frames for motion estimation. This new feature improves the prediction accuracy of inter-coding blocks significantly, but it results in a considerable increase...
详细信息
A novel approach of visual attention based video object segmentation in MPEG compressed domain is proposed in this paper. DCT coefficients and motion vectors (MVs) are firstly parsed from compressed streams. Analysis ...
详细信息
ISBN:
(纸本)9780863418365
A novel approach of visual attention based video object segmentation in MPEG compressed domain is proposed in this paper. DCT coefficients and motion vectors (MVs) are firstly parsed from compressed streams. Analysis of the scene texture is then proposed to decide the best appropriate information for region growing. MVs are exploited to perform region growing if texture is complex, otherwise DC coefficients and MVs are used together to perform region growing. Meanwhile, MVs of I frames are calculated by backward projection of MVs of subsequent P frames, then global motion compensation is performed using the MVs of I frames to obtain local MVs. Subsequently statistical region growing is exploited to segment the image into homogeneous regions. Finally an improved attention model is proposed to extract visual attention objects, which is based on position, clearness and local MVs. The attention model makes the segmentation results more accordant with human's perception. The experimental results conducted on standard test sequences demonstrate the efficient, real-time, robust performance of the proposed approach.
This paper describes our techniques to design the intra-prediction of AVS encoder for HDTV applications. The whole design is optimized in both the algorithm and architecture levels. On the algorithm level, since the P...
详细信息
This paper describes our techniques to design the intra-prediction of AVS encoder for HDTV applications. The whole design is optimized in both the algorithm and architecture levels. On the algorithm level, since the Plane mode is the most area-costly one, it is temporarily ignored. And SATD is lastly chosen as mode decision to balance the hardware implementation with performance of Rate and Distortion. On the architecture level, in addition to five-parallel system, a new scheduling of encoding process is arranged to avoid the idle cycles together by ping-pong memory architecture between the intra-prediction and entropy coding. As a result, the proposed architecture can be implemented by 11750 Slices, achieves real-time processing of HD(1920×1088) frames at a rate of 30 jps in 100 MHz operation frequency.
Multimedia applications need larger and larger bandwidth. The only way to face the demands is to provide better and faster video compression standard. Thus, A VS is created in China. To address the need for hardware a...
详细信息
Multimedia applications need larger and larger bandwidth. The only way to face the demands is to provide better and faster video compression standard. Thus, A VS is created in China. To address the need for hardware acceleration of its computationally intensive parts, high throughput hardware architectures for fast computation of the 2-D Transform Quantization Inverse Quantization and Inverse Transform are presented in this paper. In addition, two high performance system architectures are presented. The proposed hardware architectures are incorporated into two different hardware systems implemented on a Virtex 4 Pro FPGA. Simulation results show that both two hardware system architectures that are incorporated proposed architectures could provide satisfactory performances.
This paper proposed a novel approach to segment objects from the H.264 compressed video with moving background. At first, the noisy motion vectors are eliminated from the motion field by vector median filtering. Then ...
详细信息
Since the current rate control schemes in H.264 do not present the capability of efficient GOP-level bit allocation, the video quality varies greatly for sequences with the scene change or the scene complexity varying...
详细信息
ISBN:
(纸本)9780863418365
Since the current rate control schemes in H.264 do not present the capability of efficient GOP-level bit allocation, the video quality varies greatly for sequences with the scene change or the scene complexity varying from one GOP to another. To overcome the limitation, we propose a novel rate control scheme based on incremental PID algorithm. The incremental PID algorithm is introduced to minimize video quality variations in GOP-level bit allocation. Extensive simulation results show that the proposed rate control scheme, without expensive computational complexity added, decreases the average video quality variations by 15.07%.
The current density of GaN-based light emitting diode(LED)plays a strong impact on the light output and heat transfer *** this paper,the finite element simulation software ANSYS is used to simulate the thermoelectric ...
详细信息
The current density of GaN-based light emitting diode(LED)plays a strong impact on the light output and heat transfer *** this paper,the finite element simulation software ANSYS is used to simulate the thermoelectric performance of LED chip with different electrode *** conventional LED chip and the flip-chip(FC)LED with bumps are compared in terms of the current density and the temperature *** improve the thermoelectric property of FC-LED,a structure of FC-LED with vias is proposed and simulated by the *** improve the uniformity of current density of the FC-LED with vias,the electrode structure is optimized with symmetrical *** simulated results show that the optimized structure obtains a better uniform temperature distribution,lower highest temperature and lower temperature *** confirm the relationship between the current density uniformity and the temperature distribution,the current density uniformity of different chip structures are quantitatively *** results show that the optimized FC-LED with vias shows the most uniform current density,indicating that the thermal properties are closely related to the uniformity of current density.
Utilization of intermolecular Friedel-Crafts and intramolecular condensation reaction,novel 1,3-di-(pyridine-2-yl)benzene(N,C,N terdentate)skeleton with electro-withdrawing group in 6'position of pyridyl and a cyc...
详细信息
Utilization of intermolecular Friedel-Crafts and intramolecular condensation reaction,novel 1,3-di-(pyridine-2-yl)benzene(N,C,N terdentate)skeleton with electro-withdrawing group in 6'position of pyridyl and a cyclization between 6'position of pyridyl and 6 position of benzyl ring were firstly designed and *** structures of these novel N,C,N terdentate were confirmed by NMR,MS and X-ray single *** photophysical properties of these compounds were briefly explored.
Since the current rate control schemes in H.264 do not present the capability of efficient GOP-level bit allocation, the video quality varies greatly for sequences with the scene change or the scene complexity varying...
Since the current rate control schemes in H.264 do not present the capability of efficient GOP-level bit allocation, the video quality varies greatly for sequences with the scene change or the scene complexity varying from one GOP to another. To overcome the limitation, we propose a novel rate control scheme based on incremental PID algorithm. The incremental PID algorithm is introduced to minimize video quality variations in GOP-level bit allocation. Extensive simulation results show that the proposed rate control scheme, without expensive computational complexity added, decreases the average video quality variations by 15.07%.
暂无评论