Li-Fu Ding

Efficient Depth Image Based Rendering with Edge Dependent Depth Filter and Interpolation

An efficient depth image based rendering with edge dependent depth filter and interpolation is proposed. The proposed method can solve the hole-filling problem in DIBR system efficiently with high quality. The PSNR of the proposed method is better than the previous work by 6 dB and the subjective view shows the quality is better. In addition to that, the number of instruction cycles is 3.7 percent compared with the previous work

A 212 MPixels/s 4096

To provide more vivid perception, TV resolution is increasing dramatically. In addition, 3D video is emerging because it can present immersive and complete scenes. Therefore, multiview video coding (MVC) is currently being developed as an extension of H.264/AVC [1]. Disparity estimation (DE), which effectively exploits the inter-view redundancy and reduces bit rates 20% to 30%, is the most significant feature. However, DE and motion estimation (ME) require ultra-high computation and memory access. To encode a 3-view 1080p video, 82.4TOPS computing power and 54.6TB/s memory access are required with a full search algorithm. Moreover, view scalability is a critical functionality to deal with various MVC structures.

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This paper presented a novel depth map generation method - the short-term motion assisted color segmentation, which combines the pictorial, monocular and binocular depth cues of human vision. The proposed method utilizes a motion/edge registration technique to avoid the motion jitter error in common motion segmentation. And the motion/image segment adaptation algorithm matches the connected components with the motion segments. Even for static scene, the connected component algorithm is still working for the depth map generation. The experimental results show that the adaptation of motion and image segmentation improves quality and smoothness of the depth map both in the spatial and temporal domain.

2160p Multiview Video Encoder Chip for 3D/Quad Full HDTV Applications

3-D video will become one of the most significant video technologies in the next-generation television. Due to the ultra high data bandwidth requirement for 3-D video, effective compression technology becomes an essential part in the infrastructure. Thus multiview video coding (MVC) plays a critical role. However, MVC systems require much more memory bandwidth and computational complexity relative to mono-view video coding systems. Therefore, an efficient prediction scheme is necessary for encoding. In this paper, a new fast prediction algorithm, content-aware prediction algorithm (CAPA) with inter-view mode decision, is proposed. By utilizing disparity estimation (DE) to find corresponding blocks between different views, the coding information, such as rate-distortion cost, coding modes, and motion vectors, can be effectively shared and reused from the coded view channel. Therefore, the computation for motion estimation (ME) in most view channels can be greatly reduced. Experimental results show that compared with the full search block matching algorithm (FSBMA) applied to both ME and DE, the proposed algorithm saves 98.4-99.1% computational complexity of ME in most view channels with negligible quality loss of only 0.03-0.06 dB in PSNR.

Depth Map Generation for 2D-to-3D Conversion by Short-Term Motion Assisted Color Segmentation

To provide more vivid perception, more and more advanced features, like the 4k×2k resolution and the multiview functionality, are emerging for TV. For a multiview video coding (MVC) encoder, motion and disparity estimation (ME/DE) take at least half the hardware requirement. To solve these challenges, a cache-based integer ME/DE algorithm is proposed. With a cache memory as the search window buffer, a predictor-centered ME/DE algorithm is presented. The search range can be reduced to ±16 pixels with less than 0.1dB quality drop compared with full search algorithm. Based on this algorithm, an integer ME/DE chip design is realized. It can reduce 82% on-chip SRAM and 39% system bandwidth. Moreover, the search candidate requirement is also reduced by 79%. As the result, an ME/DE chip design for 4k×2k quad-HD H.264 and HDTV MVC is implemented.

Content-Aware Prediction Algorithm With Inter-View Mode Decision for Multiview Video Coding

3-D video will be the most prominent video technology in the next generation. Among the 3-D video technologies, stereo video systems are considered to be realized first in the near future. Stereo video systems require double bandwidth and more than twice the computational complexity relative to mono-video systems. Thus, an efficient coding scheme is necessary for transmitting stereo video. In this paper, a new structure of prediction core in stereo video coding systems is proposed from the algorithm level to the hardware architecture level. The joint prediction algorithm (JPA), which combines three prediction schemes, is proposed for high coding efficiency and low computational complexity. It makes the system outperform MPEG-4 temporal scalability and simple profile by 2-3 dB in rate-distortion performance. Besides, JPA also utilizes the characteristics of stereo video and successfully reduces about 80% computational complexity. Then, a new hardware architecture of the prediction core based on JPA and a modified hierarchical search block-matching algorithm is proposed. With a special data flow, no bubble cycles exist during the block-matching process. The proposed architecture also adopts the near-overlapped candidates reuse scheme to save the heavy burden of data access. Besides, both on-chip memory requirement and off-chip memory bandwidth can be reduced by the proposed new scheduling. Compared with the hardware requirement for the implementation of full search block-matching algorithm, only 11.5% on-chip SRAM and 3.3% processing elements are needed with a tiny PSNR drop, making it area-efficient while maintaining high stereo video quality and processing capability

Cache-based integer motion/disparity estimation for quad-HD H.264/AVC and HD multiview video coding

External memory bandwidth is an important issue in system-on-chip (SoC) systems. Especially in high definition (HD) video coding, the bandwidth requirement of off-chip memory is critical in video processing. In recent researches, embedded compression shows high potential on off-chip memory bandwidth reduction. Works about embedded compression have been done for low power applications. However, there is no suitable efficient embedded compression with good rate-distortion performance for high throughput applications. In this paper, an algorithm and hardware architecture of high performance lossy embedded compression is proposed to ease the bus congestion problem while keeping the latency low. Using the proposed algorithm, not only the high throughput requirement of HD video encoder is met, but also the hardware cost is relatively low. From our simulation, about 70% memory bandwidth is reduced with only 0.1 dB PSNR degradation in 1080p HD video.

Joint Prediction Algorithm and Architecture for Stereo Video Hybrid Coding Systems

3-D video will become one of the most important video technologies in the next generation of television. Due to ultra high data bandwidth requirement for 3-D video, effective compression technology becomes an essential part in the infrastructure. Thus stereo and multiview video coding (MVC) plays a critical role. However, MVC systems require much more computational complexity relative to mono-view video coding systems. Therefore, an efficient prediction scheme is necessary for encoding. In this paper, a new fast motion estimation (ME) algorithm is proposed. By utilizing disparity estimation (DE) to find corresponding blocks between different views, the coding information such as motion vectors can be effectively shared and reused from the coded view channel. Therefore, the computation for ME in most view channels can be greatly reduced. Experimental results show that compared with the full search block matching algorithm applied to both ME and DE, the proposed algorithm saves 95% computation with near-FSBMA quality.

Architecture design of high performance embedded compression for high definition video coding

Fractional motion estimation (FME) is widely used in video compression standards. In H.264/AVC, the precision of motion vector is down to quarter pixels to improve the coding efficiency. However, FME occupies over 45% of the computation complexity in an H.264 encoder and this high complexity limits the processing capability. In this paper, a single-iteration full search FME is proposed. By the algorithm and architecture co-optimization, the bandwidth to the frame buffer is reduced by 31%. Furthermore, 82% of circuit area for the Hadamard transformation and subtraction are saved from the direct implementation. Compared with prior arts, the proposed design supports 3.39 × higher throughput with only 0.02 dB PSNR drop. Thus, the specification of 4096 × 2160 quad full high definition H.264/AVC FME processing can be achieved.

Fast motion estimation with inter-view motion vector prediction for stereo and multiview video coding

Stereo video systems require double bandwidth and more than twice the computational complexity relative to mono-video systems. Thus, an efficient coding scheme is necessary for transmitting stereo video. We propose a novel stereo video coding system by exploiting a joint prediction scheme which combines three prediction schemes to achieve high coding efficiency and low computational complexity. Joint block compensation improves the visual quality. Motion vector prediction and mode pre-decision utilize the features of stereo video to reduce the computational complexity with up to 8-9 times acceleration. Experiments show that the proposed joint prediction scheme is 2 dB better than MPEG-4 TS and 3 dB better than MPEG-4 SP.