Yoshihide Tonomura

Flicker Suppression in JPEG2000 using Segmentation-Based Adjustment of Block Truncation Lengths

Flickering is a temporal visual artifact that affects compressed video. It is prominent in intra-frame video coders and is largely the result of content variations and quantization. We concentrate on flickering due to quantization. JPEG2000 uses post-compression quantization which is applied through the EBCOT algorithm. EBCOT has been found, however, to cause significant flickering in the reconstructed video. In this work, we evaluate existing flicker metrics, investigate the causes of flicker, and propose a new rate-distortion optimal algorithm that suppresses flicker. The proposed algorithm suppresses temporal flicker at a negligible cost in spatial image quality.

Improved view interpolation for side information in multiview distributed video coding

Distributed video coding (DVC) is an attractive coding scheme for distribute camera networks because it has the potential to achieve low-complexity encoding and to exploit inter-view correlation without communication among cameras during encoding. It is well-known that the quality of the side information strongly impacts the coding performance of DVC. Therefore, this paper proposes an adaptive filtering method that yields improved view interpolation side information (VISI). The proposed adaptive filter compensates the inter-view mismatches caused by heterogeneous cameras. The filter coefficients are estimated to minimize the differences between the view-interpolated frame and the decoded frame on the key frame just prior to the WZF decoding step. Simulations show that the proposed method improves VISI quality by about 2 dB on breakdancers and about 3 dB on ballet sequences.

Digital Cinema and Super-High-Definition Content Distribution on Optical High-Speed Networks

Digital cinema is a promising application that utilizes high-speed optical networks to transfer super-high-definition (SHD) images. The networks are primarily used for distributing digital cinema contents in packet data form, and are also used to support new services such as the live streaming of musicals and sport games to movie theaters. While current transfer services offer high-definition (HD) quality video, live-streaming applications will soon shift to providing cinema quality 4K content to both business and movie theaters users. The extra-high-quality 4K format enables a realistic telepresence, and will be combined with special tools such as video editing systems to realize effective remote collaboration for business workspaces. This paper introduces successive research on SHD image transmission and its application, especially in digital cinema and associated application fields.

Low-Density Generator Matrix Codes for IP Packet Video Streaming with Backward Compatibility

In this paper we propose a method of constructing packet-level LDGM codes that offer backward compatibility with conventional viewing devices. Our proposed method makes it possible to watch content even if the viewer does not support any FEC module. Moreover, the method also improves the coding efficiency through the combined use of packet division and interleaving methods. In general, there is a tradeoff between computation complexity and performance, but our proposed method improves coding efficiency by using a message passing decoding scheme that does not require any additional computation. The coding efficiency of the proposed method is evaluated both experimentally and theoretically.

Optimal Bit Allocation for Wavelet-Based Distributed Video Coding

Distributed video coding (DVC), based on the theorems proposed by Slepian-Wolf and Wyner-Ziv, is attracting attention as a new paradigm for video compression. Some of the DVC systems use intra-frame compression based on DCT. Correspondingly, we proposed a wavelet-based DVC system that utilizes the current JPEG 2000 standard. The scheme has scalability with regard to resolution and quality. However, related works does not offer that optimal bit allocation method for each sub-band coefficients. In this report, we propose a bit allocation method for a wavelet-based DVC scheme. Tests confirm that the PSNR is increased about 1-2[dB] by propose method

A conceptual foundation of NSCW transport design using an MMT standard

This paper introduces the concept of Network Supported Collaborative Work (NSCW) and its transport design based on the emerging standard of MPEG Media Transport (MMT). Based on extra-high quality 4K video technologies, NSCW is being developed to realize effective remote-collaboration for business workspaces. MMT specifies technologies for the delivery of coded media data for multimedia services over the concatenation of heterogeneous packet based network segments including bidirectional IP networks and unidirectional digital broadcasting networks. One of the core technologies for delivery is forward error correction (FEC) codes. Simulation results using our proposed MMT FEC codes show the effectiveness of the proposed method.

Digital Cinema over optical network - Status of super HD development -

Digital Cinema is a promising application that utilizes high-speed optical networks to transfer super high definition images. The networks are primary used for distributing packet data of digital cinema contents, and are also used to support new services such as the live streaming of musicals and sports games to movie theaters. While current transfer services offer HD quality video, live streaming applications will soon shift to cinema quality 4K to both business and movie theaters users. The extra-high quality 4K enables a realistic tele-presence, and will be combined with special tools such as video editing systems to realize effective remote-collaboration for business workspaces. This paper introduces current research on super high definition image transmission and its application especially in digital cinema and relevant application fields.

A New Framework for Distributed Video Coding Based on JPEG 2000

Distributed video coding (DVC), based on the theorems proposed by Slepian-Wolf and Wyner-Ziv, is attracting attention as a new paradigm for video compression. In DVC systems, several encoders will send bit streams to a single decoder which must handle all incoming bit streams. Some of the DVC systems use intraframe compression based on DCT. However, conventional DVC systems have low affinity with DCT, because they fail to generate the necessary side information until after decompressing all bit streams. In this paper, we propose a new DVC scheme that is an easy way to generate the side information before decompressing all bit streams. The scheme utilizes scalability of JPEG 2000 and the multicomponent transforms of JPEG 2000 part-2. Tests confirm that the PSNR of the new scheme is about 7[dB] higher than that of conventional JPEG 2000

Robust UHD video transmission using MMT FireFort-LDGM code

This paper introduces a FireFort-LDGM (FF-LDGM) code that is part of ISO/IEC 23008-10 (MMT AL-FEC codes) and its application to robust Ultra High Definition (UHD) video transmission. It is especially useful for UHD real-time video streaming because that it can easily handle contiguous streams containing over several thousand packets. Simulation results show its high error recovery performance with low-complexity. We also show a robust UHD video transmission scheme that uses the FF-LDGM code and its feasibility via 8K Super High-Vision live streaming over global shared IP networks at FIFA World Cup 2014 Brazil.

Unitary transform-based template protection and its properties

We focus on the feature transform approach as one methodology for biometric template protection, where the template consists of the features extracted from the biometric trait. This paper considers some properties of the unitary transform-based template protection in particular. It is known that the Euclidean distance between the templates protected by a unitary transform is the same as that between original (non-protected) ones as a property. In this paper, moreover, it is shown that it provides the same results in l2-norm minimization problems as those of original templates. This means that there is no degradation of recognition performance in authentication systems using l2-norm minimization. Therefore, the protected templates can be reissued multiple times without original templates. In addition, a DFT-based template protection scheme is proposed as an unitary transform-based one. The proposed scheme enables to efficiently generate protected templates by the FFT, in addition to the useful properties. It is also applied to face recognition experiments to evaluate the effectiveness.