Reading: Fischer QoMEX’20 — Coding Chain with Spatial Up and Down-Scaling (VVC Inter)

Using **VDSR or **RDN, 12% to 18% BD-Rate Reduction Using VMAF Compared to VVC.

Top branch: coding chain with spatial up- and downscaling; Bottom branch: conventional coding

In this paper, On Versatile Video Coding at UHD with Machine-Learning-Based Super-Resolution (Fischer QoMEX’20), by Friedrich-Alexander-Universit¨at Erlangen-N¨urnberg (FAU), is shortly presented. I read this because I work on video coding research. In this paper:

• The input frame is firstly downsampled, then encoded.
• This encoded frame is then decoded, and upsampled by super resolution network, as shown at the top branch of the figure above.

This is a paper in 2020 QoMEX. (Sik-Ho Tsang @ Medium)

Outline

1. **VDSR**
2. **RDN**
3. Experimental Results

1. VDSR

VDSR architecture

• In this paper, authors try to use VDSR for the upsampling part.
• Different from original VDSR, this one uses DIV2K dataset for training.
• (If interested, please feel free to read VDSR.)

2. RDN

RDN architecture

RDB structure to extract local features

• Another network authors try to use is RDN.
• We can just treat it as a more powerful network for upsampling comparing with VDSR.
• (If interested, please feel free to read RDN.)

3. Experimental Results

3.1. BD-Rate

BD-Rate Reduction (%) for two QP ranges using conventional VTM coding chain as anchor

• VTM-5.0 is used with Random Access Configuration.
• L-SEABI is the Gaussian filter upsampling approach.
• Considering a very low video quality (QPconv ={42, 44, 46, 48}), coding with the investigated coding chain with spatial downscaling results in BD-Rate reduction with respect to PSNR above 9 %.
• At best, the investigated coding chain with RDN can save 39.5 % for the FoodMarket4 sequence.

3.2. Time Complexity

• VDSR takes around 1 second to upscale the Y channel of a full HD frame to 4K resolution on a NVIDIA GeForce RTX 2080 Ti.
• On the same unit, RDN takes between 6 and 8 seconds.
• The L-SEABI takes around 1 second on an Intel Xeon E3–1275 v6 @ 3.8 GHz in the proposed coding chain for upscaling the Y-channel.

Reference

[2020 QoMEX] [Fischer QoMEX’20] On Versatile Video Coding at UHD with Machine-Learning-Based Super-Resolution

Codec Inter Prediction

H.264 [DRNFRUC & DRNWCMC] HEVC [CNNIF] [Zhang VCIP’17] [NNIP] [GVTCNN] [Ibrahim ISM’18] [VC-LAPGAN] [VI-CNN] [CNNMCR] [FRUC+DVRF] [FRUC+DVRF+VECNN] [RSR] [Zhao ISCAS’18 & TCSVT’19] [Ma ISCAS’19] [Xia ISCAS’19] [Zhang ICIP’19] [ES] [GVCNN] [FRCNN] [Pham ACCESS’19] [CNNInvIF / InvIF] [CNN-SR & CNN-UniSR & CNN-BiSR] [DeepFrame] [U+DVPN] [Multi-Scale CNN] [Klopp TIP’20] AVS3 [Zhang ICMEW’20] VVC [FRUC+DVRF+VECNN] [ScratchCNN] [Fischer QoMEX’20]

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