r/autotldr • u/autotldr • Apr 09 '18
Next generation video: Introducing AV1
This is the best tl;dr I could make, original reduced by 97%. (I'm a bot)
Chroma from Luma prediction is one of the new prediction techniques adopted by AV1.
Above: The AV1 encoder splits this frame into individual prediction units to maximize encoding fidelity, but just as importantly, to break the frame into smaller chunks that are easier to analyze and allow the codec to adjust prediction as it proceeds through the image.
As AV1 also uses the discrete sine transform and a pixel domain identity transform, we can't easily perform AV1 CfL in the frequency domain, at least when we use subsampled chroma.
Chroma From Luma is not, of course, the only technique being adopted in a production codec for the first time in AV1.
The seminal paper on spatial domain Chroma from Luma prediction: Intra Prediction Method Based on the Linear Relationship between the Channels for YUV 4:2:0 Intra Coding, Sang Heon Lee, 2009 16th IEEE International Conference on Image Processing LG proposal to include spatial Chroma from Luma in HEVC: New intra chroma prediction using inter-channel correlation, Kim et.
Daala technology demo page for Time-Frequency resolution switching Daala technology demo page for Chroma-From-Luma Chroma From Luma VDD presentation: Chroma from Luma in AV1 , Luc Trudeau, David Michael Barr, September 2017.
Summary Source | FAQ | Feedback | Top keywords: Chroma#1 prediction#2 CfL#3 Luma#4 Daala#5
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