Recently, the advances in transform coding have contributed to significant bitrate saving for the next generation of video coding. In particular, the combination of different discrete trigonometric transforms (DTT’s) was adopted in the Joint Video Exploration Team (JVET) solution, as well as the Bench-Mark Set (BMS) of the future video coding standard (Versatile…
Thanks to the increasing number of images stored in the cloud, external image similarities can be leveraged to efficiently compress images by exploiting inter-images correlations. In this paper, we propose a novel image prediction scheme for cloud storage. Unlike current state-of-the-art methods, we use a semi-local approach to exploit inter-image correlation. T…
Representation of 3D scenes is gaining popularity in industry, notably for Virtual Reality, Augmented Reality, and 360° Video. The point cloud format is well suited for such representations. Indeed, point clouds can be created with a simple capture process and modest processing, enabling a real-time, end-to-end point cloud distribution chain. However, point clou…
The movie industry has been using Unmanned Aerial Vehicles as a new tool to produce more and more complex and aesthetic camera shots. However, the shooting process currently rely on manual control of the drones which makes it difficult and sometimes inconvenient to work with. In this paper we address the lack of autonomous system to operate generic rotary-wing d…
This paper describes a novel scheme to reduce the quantization noise of compressed videos and improve the overall coding performances. The proposed scheme first consists in clustering noisy patches of the compressed sequence. Then, at the encoder side, linear mappings are learned for each cluster between the noisy patches and the corresponding source patches. Th…
The migration from high-definition TV to ultrahigh definition (UHD) is already underway. In addition to an increase of picture spatial resolution, UHD potentially provides more color by introducing a wider color gamut, and better contrast by moving from standard dynamic range (SDR) to high dynamic range (HDR). The transition from SDR to HDR will require distribu…
In recent video coding standards, the introduction of multiple transform selection (MTS) has significantly improved coding efficiency. The latest standard, Versatile Video Coding (VVC), adopted implicit MTS as an alternative tool to explicit MTS. This tool reduces the encoder complexity by inferring the optimal transform type from decoder-side information instea…
Representation of 3D scenes is gaining popularity in industry, notably for Virtual Reality, Augmented Reality, and 360° Video. The point cloud format is well suited for such representations. Indeed, point clouds can be created with a simple capture process and modest processing, enabling a real-time, end-to-end point cloud distribution chain. However, point clou…
Current video coding standards like HEVC, VP9, VVC, AV1, etc., involve partitioning a picture into coding tree units (CTU), typically corresponding to 64x64 or 128x128 picture areas. Each CTU is partitioned into coding blocks following a recursive coding tree. In recently published perceptual video encoding methods, the CTU is used as the spatial unit to assign …
Recent years have shown significant advances in immersive media experiences. Three-dimensional representation formats allow for new forms of entertainment and communication. In this context, point cloud data has emerged as a promising enabler for such experiences. Because efficient enough point cloud compression technologies are still to be found, the Moving Pic…
HDR Solution presentation
With the advent of ultra-high-definition TV services, high dynamic range (HDR) and wide color gamut (WCG) have become two highly desired image quality improvements for delivering immersive video experiences to the consumer mass market. Capture and rendering technologies have reached a level of maturity that now allows HDR and WCG enhanced video to be deployed ac…
This paper addresses the estimation of accurate long-term dense motion fields from videos of complex scenes. With computer vision applications such as video editing in mind, we exploit optical flows estimated with various inter-frame distances and combine them through multi-step integration and statistical selection (MISS). In this context, managing numerous com…
Transform and partitioning represent core components of the video coding architectures. Compared with HEVC, VVC is characterized by higher number of transform types, additional transform level (LFNST) and more flexible partitioning via the binary tree and ternary tree. This flexibility in transform and partitioning provides about 2% and 10% coding gain. Neverthe…
research Paper / Aug 2021 / Video coding, Compression, Machine learning/ Deep learning /Artificial Intelligence
Deep bi-prediction blending. This paper presents a learning-based method to improve bi-prediction in video coding. In conventional video coding solutions, block-based motion compensation blocks from already decoded reference pictures stand out as the main tool used to predict the current frame. Especially, bi-predicted blocks, i.e. blocks that combine two differ…
Adaptive transform learning schemes have been extensively studied in the literature with a goal to achieve better compression efficiency compared to extensively used Discrete Cosine Transforms (DCT) inside a video codec. These transforms are learned offline on a large training set and are tested either in competition with or in place of the core transforms i.e. …
research Paper / Sep 2021 / Video coding, Compression, Machine learning/ Deep learning /Artificial Intelligence Neural network
Despite many modern applications of Deep Neural Networks (DNNs), the large number of parameters in the hidden layers makes them unattractive for deployment on devices with storage capacity constraints. In this paper we propose a Data-Driven Low-rank (DDLR) method to reduce the number of parameters of pretrained DNNs and expedite inference by imposing low-rank st…
This paper presents CompressAI, an open-source library that provides custom operations, layers, models and tools to research, develop, and evaluate end-to-end image and video codecs. In particular, CompressAI includes pre-trained models and evaluation tools to compare learned methods with traditional codecs. Multiple models from the state-of-the-art on learned e…
In this paper, we propose a novel scheme for scalable image coding based on the concept of epitome. An epitome can be seen as a factorized representation of an image. Focusing on spatial scalability, the enhancement layer of the proposed scheme contains only the epitome of the input image. The pixels of the enhancement layer not contained in the epitome are then…
Film grain is often desirable feature in video production. Content creators can use film grain to create a natural appearance and to express their creative-artistic impression. With the expansion of the streaming services, prior to delivery, video typically undergo various pre-processing steps, where the inevitable video compression is presented. Modern video co…
Displays' new rendering capabilities combined with the ever-growing number of video applications have fueled the emergence of new video formats addressing wider color gamut and larger frame size. Thus, the need in scalable compression technology to provide backward compatibility with legacy devices and capitalize on the superior compression performance of High E…
Summary form only given. This paper presents two sets of modifications to band offset type of the Sample Adaptive Offset technique in HEVC. First, some constraints on the SAO semantics are added to solve sub-optimal syntax issue and to exploit the actual range information of reconstructed samples. Next, the classification process is adapted to the particular sam…
"JVET has developed a new Enhanced Compression Model (ECM) for testing future video coding algorithms on top of the Versatile Video Coding (VVC) standard. Reference Picture Resampling (RPR) is a powerful tool that improves video coding efficiency of next generation like Versatile Video Coding (VVC). This feature is well designed to support frame changing resolut…
The proposed Single Layer SDR backward compatible HDR video distribution solution detailed in this paper, named SL-HDR1, and standardized in ETSI TS 103 433 specification, aims at addressing these issues. SL-HDR1 leverages SDR distribution networks and services already in place. It enables both high quality HDR rendering on HDR-enabled CE devices, while also off…
Focusing on error-correction methods and codes, a systems level design is presented for encoding movies and digital information in DNA storage. A source of data (e.g., movies, audio) is compressed, efficiently encoded with redundant information, modulated, and stored in multiple DNA oligonucleotide strands. The goal is to decode the source from the DNA reliably …
As the video industry begins deployment of ultrahigh-definition TV in both professional and consumer markets, including support for higher dynamic range and wider color gamut services is considered essential within the industry. Higher dynamic range and wider color gamut offer end users a significantly enhanced viewing experience by supporting intensity ranges a…
The upcoming MPEG Immersive Video (MIV) standard will enable storage and distribution of immersive video content over existing and future networks, for playback with 6 full or partial degrees of freedom of view position and orientation. The demo showcases a VOD server streaming MIV encoded immersive video contents up to a decoding client where an HMD is connecte…
research Paper / Apr 2024 / Compression, Video coding, Machine learning/ Deep learning /Artificial Intelligence
"The last standard Versatile Video Codec (VVC), aims to im- prove the compression efficiency by saving around 50% of bitrate at the same quality compared to its predecessor High Efficiency Video Codec (HEVC). However, this comes with a significant rise in computational complexity due to the new added tools in the encoder side. This paper proposes a speed- up tec…
This paper presents experimentation results related to adaptive video content mapping used as compression tool of HDR-PQ content. The purpose of adaptive video content mapping is to adapt the video signal dynamically depending on its statistical properties in order to better exploit the signal codewords range. Adaptive video content mapping has been investigated…
research Paper / Sep 2021 / Video coding, Machine learning/ Deep learning /Artificial Intelligence, Image processing, Computer Graphics
Recently, learning methods have been designed to create Multiplane Images (MPIs) for view synthesis. While MPIs are extremely powerful and facilitate high quality renderings, a great amount of memory is required, making them impractical for many applications. In this paper, we propose a learning method that optimizes the available memory to render compact and ad…
This paper presents an adaptive clipping technique with optimized syntax in the video coding Joint Exploratory Model (JEM), which exploits the signal characteristics of the video sequence. The component-wise clipping bounds are coded for each slice. Two encoding methods leveraging the efficiency of the proposed technique are then described. The first one consist…
In this paper, we propose a novel interpolation of reference samples for intra prediction in Versatile Video Coding (VVC). To interpolate a predictor value between two reference samples, the method uses four nearest reference samples, as does the existing cubic filter in VVC, but with a simpler design that does not require to pre-compute the filter coefficients.…
The Versatile Video Coding (VVC) is the most recent video coding standard jointly developed by MPEG (ISO/IEC) and VCEG (ITU-T) in the JVET (Joint Video Experts Team).
Recent work in video compression has shown that using multiple 2D transforms instead of a single transform in order to de-correlate residuals provides better compression efficiency. These transforms are tested competitively inside a video encoder and the optimal transform is selected based on the Rate Distortion Optimization (RDO) cost. However, one needs to enc…