Novel Chroma Sampling Methods for CFA Video Compression in AVC, HEVC and VVC

The images obtained by the camera sensors are stored in the format of CFA, Color Filter Array, which only contains limited information about the R, G, and B signals of images. The images in CFA are upsampled into RGB 444 format by demosaicking algorithms, converted into YCbCr 444, then chroma-downsa...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on circuits and systems for video technology 2020-09, Vol.30 (9), p.3167-3180
Main Authors: Lin, Ting-Lan, Yu, Yi-Chieh, Jiang, Kun-Hu, Liang, Chi-Fu, Liaw, Pei-Sin
Format: Article
Language:English
Subjects:
Algorithms
chroma-subsampling
chroma-upsampling
Color filter array (CFA)
Format
H.264/AVC
HEVC (high efficiency video compression)
High efficiency video coding
Image coding
Image color analysis
Image compression
Image reconstruction
Optimization
Pixels
Sampling methods
Sensor arrays
Signal to noise ratio
Video compression
VVC (versatile video coding)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The images obtained by the camera sensors are stored in the format of CFA, Color Filter Array, which only contains limited information about the R, G, and B signals of images. The images in CFA are upsampled into RGB 444 format by demosaicking algorithms, converted into YCbCr 444, then chroma-downsampled into YCrCb 420 format for image/video compression. In this paper, a novel chroma-downsampling method is developed to improve a state-of-the-art method. The optimization problem for the proposed method considers more factors and provides a better closed-form solution for the optimally sampled chroma values. Reversely in the decoder, a chroma-upsampling method is required for the image reconstruction. In the proposed chroma-upsampling method, the neighboring chroma pixels and their distances to the recovered pixel are considered; the procedure is to produce weightings to redistribute the total pixel values in the original estimates. Combining the proposed chroma-downsampling and the proposed chroma-upsampling works, the proposed method outperforms the state-of-the-art method by BDPSNR (Bjøntegaard Delta peak signal-to-noise ratio) 0.3161 for H.264/AVC, 0.3845 for HEVC (High Efficiency Video Compression) and 0.3739 for VVC (Versatile Video Coding), averaged over all tested videos and all 7 different considered CFA formats.
ISSN:1051-8215
1558-2205
DOI:10.1109/TCSVT.2019.2939280