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A secure identification scheme for JPEG 2000 code-streams is proposed in this paper. The aim is to securely identify JPEG 2000 images generated from the same original image, without decoding images. Features used for the identification are extracted from header parts in a JPEG 2000 codestream. The proposed scheme does not provide any false negative matches under various compression ratios, while most...
At low bit-rates, the conventional image coding standards, e.g., JPEG and JPEG 2000, do not have good compression performance due to the insufficiency of coding bits. A common solution to this problem is downsampling before encoding and reconstruction after decoding. Inspired by the wavelet domain downsampling-based compression scheme, we establish an enhanced low bit-rates coding framework by making...
In this paper, we propose a subband-based stereo to 5.1-channels upmixing method using deep neural networks (DNNs) in MPEG-H 3D audio framework. In the training stage, DNN models of rear and center channels are respectively trained by using log-spectral magnitudes of quadrature mirror filter (QMF) sub-bands. In the upmixing stage, stereo input signals are converted into rear and center channels by...
Coarse-grained reconfigurable systems are capable of providing flexibility and optimal performance, suitable for nowadays embedded computing systems. The RPCT project has tackled the issue of their complex design, debug and mapping. Demonstration of its potentials and features are presented on an MPEG HEVC motion compensation use case.
Parallel decoding of encoded data streams is an important scheme that is widely applied in image and video applications. Especially with the increasing demand on higher resolutions and frame rates, parallel decoding becomes very useful to meet the throughput requirements. Parallel decoding is conventionally enabled by inserting markers into the variable length code (VLC) stream. The markers allow...
MPEG Surround (MPS) has been widely known as both efficient technique for encoding multi-channel audio signals and rich-features audio standard. However, the generation of residual signal in the basis of a single module in MPS encoder can be considered as not optimal to compensate for error due to down-mixing process. In this paper, an improved residual coding method is proposed in order to ensure...
We propose an algorithm that accomplishes transform-coded, spatiotemporal, pel-recursive video compression. Traditional pel-recursive coders obtain sophisticated spatio-temporal predictions for the current pixel based on previously decoded data. The resulting per-pixel prediction errors are encoded independently so that the decoder can use previously-encoded pixels in the prediction of the current...
Our challenge is the design of a “universal” bit-efficient image compression approach. The prime goal is to allow reconstruction of images with high quality. In addition, we attempt to design the coder and decoder “universal”, such that MPEG-7-like low-and mid-level descriptors are an integral part of the coded representation. To this end, we introduce a sparse Mixture-of-Experts regression approach...
The upcoming JPEG XT standard for High Dynamic Range (HDR) images defines a common framework for the lossy and lossless representation of high-dynamic range images. It describes the decoding process as the combination of various processing tools that can be combined freely. In this paper we analyze the coding efficiency of different decoding tools through a large scale objective quality testing using...
This paper studies the influence of JPEG-XT on LDR generation using TMOs'. JPEG-XT encodes HDR images into a two layer scheme, encoding a LDR version of the image in a base layer, and the residual HDR information in an enhancement layer. The question addressed here is to understand if this model allows to extract a new LDR representation using a different TMO, independently of the TMO used to generate...
We present a novel lossless image compression algorithm. It achieves better compression than popular lossless image formats like PNG and lossless JPEG 2000. Existing image formats have specific strengths and weaknesses: e.g. JPEG works well for photographs, PNG works well for line drawings or images with few distinct colors. For any type of image, our method performs as good or better (on average)...
Light field imaging is a promising new technology that allows the user not only to change the focus and perspective after taking a picture, as well as to generate 3D content, among other applications. However, light field images are characterized by large amounts of data and there is a lack of coding tools to efficiently encode this type of content. Therefore, this paper proposes the addition of two...
Decorrelator is a module to restore the specific correlation properties between stereo signals in parametric stereo audio decoder, which is vital to keep the spatial information of the stereo signals. Generally, the existing decorrelators are prone to have a comb-filter effect which results in an undesirable “metallic” sound and produce temporal smearing such as pre- and post-echoes artefacts. This...
A networked controlled system (NCS) in which the plant communicates to the controller over a channel with random delay loss is considered. The channel model is motivated by recent development of tree codes for NCS, which effectively translates an erasure channel to one with random delay. A causal transform coding scheme is presented which exploits the plant state memory for efficient communications...
Currently, the data storage medium in digital form are widely applied in various fields, including in the medical world. The excessive size of the digital medical image digital poses problems in terms of storage and the time to transmit these images through the Internet. To overcome these problems, a digital image compression can be conducted. This procedure is conducted to maintain the image quality...
The coding performance of the normative encoder of the JPEG XT in profile is analyzed and the problem on the encoder is summarized in this paper. It is pointed out that there is a mismatch in the handling of the quantization error between the normative encoder and the standard decoder. To avoid this problem, an improved structure has been proposed with consideration of the mismatch. The experimental...
In this information age, a efficient video encoding/decoding technology will help reducing information redundancy, delaying processing, enhancing the robustness, improving visual perception of quality, increasing the compression ratio, etc. At first, this article describes the history of video encoding/decoding standards development. Research on the key technologies of H.264 coding standard currently...
This paper presents a method for efficient compression of high dynamic range (HDR) and wide color gamut (WCG) video data. The proposed solution consists of two major elements: a conventional video codec (e.g., HEVC) and pre-and post-processing steps applied prior to encoding and after decoding process, respectively. The proposed HDR/WCG video coding system can be configured to provide two configurations:...
We address the problem of optimizing the decoding of JPEG-compressed images, employing an approach based on the “generalized” graph Laplacian, a higher-order generalization of the usual graph Laplacian. The optimal decoding problem is formulated as a non-smooth but convex problem over a graph, and solved via the alternating directions method of multipliers. While similar, graph-based optimized decoding...
Transform coding tools in video coding have traditionally relied on the Discrete Cosine Transform Type II (DCT-II) to map residual signals to a new domain where quantization and entropy coding tools achieve a better coding efficiency than in the spatial domain. However, the DCT-II is not sufficient to model all different types of residual signals efficiently, especially in the intra-predicted blocks...
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