JVET-AN0142 Non-EE2: GPM without blending for screen content [J.-Y. Kim, J.-H. Son, K. Kim, J.-S. Kwak (WILUS)]

For screen content videos, a blending width of 1/4τ is consistently used for SGPM-coded blocks. However, the adaptive blending method remains enabled for the GPM-coded blocks. This contribution proposes the GPM-coded blocks in without blending for screen content, consistent with the SGPM without blending. Based on ECM-18.0, corresponding simulation results are reported.

RA configuration:

Class F: -0.02%, 0.04%, 0.05%; 99.7% enc time, 100.0% dec time

Class TGM: -0.12%, -0.12%, -0.08%; 99.2% enc time, 100.1% dec time

LDB configuration:

Class F: -0.18%, -0.03%, 0.04%; 99.9% enc time, 100.2% dec time

Class TGM: -0.20%, -0.30%, -0.02%; 99.2% enc time, 98.7% dec time

It was commented that for mixed content (as some sequences in class F) it may not be helpful to turn off the blending. Otherwise, it is definitely useful for graphics content.

It was agreed to investigate this in an EE.