JVET-AN0124 AHG9: Additional features in display rectangles SEI message [R. Imichi, Y. Tokumo, T. Ikai (Sharp)]

The display rectangles (DR) SEI message is specified in technologies under consideration for future extensions of VSEI (version 9) in JVET-AM2032.

It is asserted that the current display rectangles (DR) SEI message has three problems:

1. There is no functionality to fill the i-th rectangle with a gradient.
2. The decoded picture can be centered relative to the i-th display rectangle without additional syntax, but there is no functionality to do that.
3. Some editorial improvements should be conducted.

Slide deck to be uploaded in new version.

It was suggested to make the semantics more compact, to use variables to indicate the different directions.

Decision: Agreed to items 1 and 2.

Delegated Item 3 to editors.

JVET-AN0124 AHG9: Additional features in display rectangles SEI message