ViSTRA2: Video Coding using Spatial Resolution and Effective Bit Depth Adaptation
This addresses the problem of improving compression efficiency for video coding standards like HEVC and VVC, offering incremental gains over existing methods.
The paper tackles video compression by proposing ViSTRA2, a framework that adapts spatial resolution and bit depth based on perceptual criteria, achieving average BD-rate savings of 12.6% (PSNR) and 19.5% (VMAF) over HEVC and 5.5% (PSNR) and 8.6% (VMAF) over VVC.
We present a new video compression framework (ViSTRA2) which exploits adaptation of spatial resolution and effective bit depth, down-sampling these parameters at the encoder based on perceptual criteria, and up-sampling at the decoder using a deep convolution neural network. ViSTRA2 has been integrated with the reference software of both the HEVC (HM 16.20) and VVC (VTM 4.01), and evaluated under the Joint Video Exploration Team Common Test Conditions using the Random Access configuration. Our results show consistent and significant compression gains against HM and VVC based on Bjønegaard Delta measurements, with average BD-rate savings of 12.6% (PSNR) and 19.5% (VMAF) over HM and 5.5% (PSNR) and 8.6% (VMAF) over VTM.