面向无损屏幕内容压缩的增强调色板建模

Surface Compression Using Dynamic Color Palettes

Off-chip memory traffic is a major source of power and energy consumption on mobile platforms. A large amount of this off-chip traffic is used to manipulate graphics framebuffer surfaces. To cut down the cost of accessing off-chip memory, framebuffer surfaces are compressed to reduce the bandwidth consumed on surface manipulation when rendering or displaying. In this work, we study the compression properties of framebuffer surfaces and highlight the fact that surfaces from different applications have different compression characteristics. We use the results of our analysis to propose a scheme,…

Optimization of Probability Distributions for Residual Coding of Screen Content

Probability distribution modeling is the basis for most competitive methods for lossless coding of screen content. One such state-of-the-art method is known as soft context formation (SCF). For each pixel to be encoded, a probability distribution is estimated based on the neighboring pattern and the occurrence of that pattern in the already encoded image. Using an arithmetic coder, the pixel color can thus be encoded very efficiently, provided that the current color has been observed before in association with a similar pattern. If this is not the case, the color is instead encoded using a col…

用于改进无损屏幕内容压缩的图像分割

Image Segmentation For Improved Lossless Screen Content Compression

本文提出一种图像分割方法，将屏幕内容图像中的自然区域与合成区域分离，作为预处理步骤补充软上下文形成（SCF）压缩方法，分别建模编码，实现比特率最高降低11.6%（相对HEVC）和1.52%（相对旧版SCF）。

基于亮度引导的软上下文形成的无损4:2:0屏幕内容编码

Lossless 4:2:0 Screen Content Coding Using Luma-Guided Soft Context Formation

针对软上下文形成编码器不原生支持YCbCr 4:2:0格式的问题，本文通过Y和CbCr平面顺序编码、亮度引导的色度预测增强及传输亮度-色度组合辅助信息，将其扩展到该格式，在大型数据集上平均比特率比HEVC-SCC低5.66%。

A Lossless Intra Reference Block Recompression Scheme for Bandwidth Reduction in HEVC-IBC

The reference frame memory accesses in inter prediction result in high DRAM bandwidth requirement and power consumption. This problem is more intensive by the adoption of intra block copy (IBC), a new coding tool in the screen content coding (SCC) extension to High Efficiency Video Coding (HEVC). In this paper, we propose a lossless recompression scheme that compresses the reference blocks in intra prediction, i.e., intra block copy, before storing them into DRAM to alleviate this problem. The proposal performs pixel-wise texture analysis with an edge-based adaptive prediction method yet no si…

基于软上下文形成的VVC屏幕内容编码改进

Improved Screen Content Coding in VVC Using Soft Context Formation

本研究针对屏幕内容图像特性，提出结合软上下文形成的增强VVC编码方法，通过学习分块分层编码并利用解码层信息优化，实现了4.98%的Bjontegaard-Delta码率增益。