Combined neural network-based intra prediction and transform selection

Explainable Machine Learning based Transform Coding for High Efficiency Intra Prediction

Machine learning techniques provide a chance to explore the coding performance potential of transform. In this work, we propose an explainable transform based intra video coding to improve the coding efficiency. Firstly, we model machine learning based transform design as an optimization problem of maximizing the energy compaction or decorrelation capability. The explainable machine learning based transform, i.e., Subspace Approximation with Adjusted Bias (Saab) transform, is analyzed and compared with the mainstream Discrete Cosine Transform (DCT) on their energy compaction and decorrelation …

用于帧内预测的可分离路径图变换的自适应在线学习

Adaptive Online Learning of Separable Path Graph Transforms for Intra-prediction

本文提出一种基于可分离路径图变换的自适应在线学习方法，通过顺序K-means聚类从相似重建区域学习变换，用于提升帧内预测纹理数据的去相关性能，并证明其显著优于H.264/AVC的DCT。

Multi-resolution intra-predictive coding of 3D point cloud attributes

We propose an intra frame predictive strategy for compression of 3D point cloud attributes. Our approach is integrated with the region adaptive graph Fourier transform (RAGFT), a multi-resolution transform formed by a composition of localized block transforms, which produces a set of low pass (approximation) and high pass (detail) coefficients at multiple resolutions. Since the transform operations are spatially localized, RAGFT coefficients at a given resolution may still be correlated. To exploit this phenomenon, we propose an intra-prediction strategy, in which decoded approximation coeffic…

Lossless Image and Intra-frame Compression with Integer-to-Integer DST

Video coding standards are primarily designed for efficient lossy compression, but it is also desirable to support efficient lossless compression within video coding standards using small modifications to the lossy coding architecture. A simple approach is to skip transform and quantization, and simply entropy code the prediction residual. However, this approach is inefficient at compression. A more efficient and popular approach is to skip transform and quantization but also process the residual block with DPCM, along the horizontal or vertical direction, prior to entropy coding. This paper e…

通过CNN-分层注意力Transformer混合加速HEVC帧内划分

Accelerating HEVC Intra Partitioning via a CNN-Hierarchical Attention Transformer Hybrid

提出HFViT混合架构，融合重参数化深度可分离卷积与分层注意力Transformer，以低复杂度实现高效全局信息传播，在HEVC帧内划分预测中降低VMAF BD-rate惩罚并保持低CPU延迟。

On Energy Compaction of 2D Saab Image Transforms

The block Discrete Cosine Transform (DCT) is commonly used in image and video compression due to its good energy compaction property. The Saab transform was recently proposed as an effective signal transform for image understanding. In this work, we study the energy compaction property of the Saab transform in the context of intra-coding of the High Efficiency Video Coding (HEVC) standard. We compare the energy compaction property of the Saab transform, the DCT, and the Karhunen-Loeve transform (KLT) by applying them to different sizes of intra-predicted residual blocks in HEVC. The basis func…