IVC4-P: Image and Video Compression 4
6:00pm - 6:05pm
VMAF Based Rate-Distortion Optimization for Video Coding
Google LLC, United States of America
Video Multi-method Assessment Fusion (VMAF) is a machine-learning based video quality metric. It is experimentally shown to provide higher correlation with human visual system as compared to conventional metrics like peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) in many scenarios and has drawn considerable interest as an alternative metric to evaluate the perceptual quality. This work proposes a systematic approach to improve the video compression performance in VMAF. It is composed of multiple components including a preprocessing stage with a complement automatic filter parameter selection, and a modified rate-distortion optimization framework tailored for VMAF metric. The proposed scheme achieves on average 37% BD-rate reduction in VMAF, as compared to conventional video codec optimized for PSNR.
6:05pm - 6:10pm
A Comparative Analysis of the Time and Energy Demand of Versatile Video Coding and High Efficiency Video Coding Reference Decoders
Multimedia Communications and Signal Processing, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
This paper investigates the decoding energy and decoding time demand of VTM-7.0 in relation to HM-16.20. We present the first detailed comparison of two video codecs in terms of software decoder energy consumption. The evaluation shows that the energy demand of the VTM decoder is increased significantly compared to HM and that the increase depends on the coding configuration. For the coding configuration randomaccess, we find that the decoding energy is increased by over 80% at a decoding time increase of over 70%. Furthermore, results indicate that the energy demand increases by up to 207% when Single Instruction Multiple Data (SIMD) instructions are disabled, which corresponds to the HM implementation style. By measurements, it is revealed that the coding tools MIP, AMVR, TPM, LFNST, and MTS increase the energy efficiency of the decoder. Furthermore, we propose a new coding configuration based on our analysis, which reduces the energy demand of the VTM decoder by over 17% on average.
6:10pm - 6:15pm
Geometric Partitioning Merge Mode with Motion Vector Refinement
This paper describes Geometric Partitioning Merge mode with MV refinement. This extension allows more accurate MV for GPM partitions, resulting in higher coding efficiency. Four methods are studied to understand trade-off in terms of coding efficiency and complexity for different levels of refinement flexibility. Fast algorithms of the proposed methods are also described to allow manageable encoding run time options. Simulation results show that the most flexible method can achieve -0.25% and -0.51% coding gains with relative encoder run time of 129% and 133% for RA and LB test conditions, respectively. Its fast version provides -0.12% and -0.23% coding gains with relative encoder run time of 101% and 105% for RA and LB test conditions, respectively.
6:15pm - 6:20pm
Optimizing Rate-Distortion Performance of Motion Compensated Wavelet Lifting with Denoised Prediction and Update
Friedrich-Alexander University Erlangen-Nuernberg, Germany
Efficient lossless coding of medical volume data with temporal axis can be achieved by motion compensated wavelet lifting. As side benefit, a scalable bit stream is generated, which allows for displaying the data at different resolution layers, highly demanded for telemedicine applications. Additionally, the similarity of the temporal base layer to the input sequence is preserved by the use of motion compensated temporal filtering. However, for medical sequences the overall rate is increased due to the specific noise characteristics of the data.
The use of denoising filters inside the lifting structure can improve the compression efficiency significantly without endangering the property of perfect reconstruction. However, the design of an optimum filter is a crucial task. In this paper, we present a new method for selecting the optimal filter strength for a certain denoising filter in a rate-distortion sense. This allows to minimize the required rate based on a single input parameter for the encoder to control the requested distortion of the temporal base layer.
6:20pm - 6:25pm
A quaternary code mapping resistant to the sequencing noise for DNA image coding
Laboratoire I3S / CNRS, France
The exponential growth in the generation of digital information creates a big challenge for data storage given the capacity limitations of conventional storage devices. Recent works have proposed DNA as a means of digital data storage proposing a novel solution for long-term storage. Although having many advantages, DNA storage is a challenging topic due to the error-prone process of DNA sequencing (reading). To deal with this error most existing works focus on the introduction of error-correction methods. However, most of those methods introduce important redundancy without promising full error correction for the widely used sequencing method using the Nanopore sequencer. This work focuses on noise resistance rather than error-correction proposing a new algorithm for optimally assigning VQ indices to DNA codewords while reducing the visual impact of substitution errors that are caused during sequencing.