JVET-AM0168 [AHG9/AHG13] Implementation in VTM TuC of the film grain regions characteristics SEI message [F. Urban, E. François, P. de Lagrange (InterDigital), G. Teniou (Tencent)]

See section 6.4.7.

JVET-AM0168 [AHG9/AHG13] Implementation in VTM TuC of the film grain regions characteristics SEI message [F. Urban, E. François, P. de Lagrange (InterDigital), G. Teniou (Tencent)]

JVET-AM0168 also relates to software for SEI messages

This contribution provides a status of the VTM software implementation of the Film Grain Regions Characteristics (FGR) SEI message, defined in the VSEI TuC. It states that the single model version (one model per picture), aligned with the TuC specification JVET-AG2032, is available in a branch of the VTM TuC git repository. It also states that the interest of the FGR SEI message, in single model version, has been demonstrated by showcases in JVET-AH0212. It is proposed to include the FGR SEI message in the WD of the next VSEI specification version (v5), when this version is initiated.

It is proposed:

• to agree to include the FGR SEI message in the first version of the WD VSEI v5 specification when created,
• to decide which of the single model version (as defined in JVET-AG2032) or the multi-model version (as documented in JVET-AL2032) is to be moved to v5
  • Such a decision should depend on both the availability of the software implementation and the confirmed interest from the group

It is noted that there is not yet a WD for VSEI v5. Decisions on including SEI messages into v5 will wait until that work has started.

JVET-AM0168[AHG9/AHG13]...

JVET-AM0181 AHG9: Proposed new SEI message on localization and mapping [G. Teniou, S. Wenger, A. Hinds, J. Ricard (Tencent), Louis Kerofsky, Yong He, Shuai Zhao (Qualcomm)]

This document proposes a new SEI message designed to support the 3d model creation from 2d video streams. The proposed SEI message conveys essential metadata such as camera intrinsic (focal length, principal point, …) parameters and camera extrinsic (position and orientation) parameters. This metadata is crucial for algorithms that create 3D models such as 3d Gaussian Splatting (3DGS) and to assist the rendering process.

The radial distortion aspect of this SEI message is a subset of what is provided in the Lens optical correction (LOC) SEI.

It was questioned why 3dmr_camera_id is included in the intrinsic parameters.

The focal length is expressed in pixels, which should be for the capture resolution, which may not be the same as the coded picture.

This condition is problematic for future extensibility: if( 3dmr_camera_model ! = 1 )

It was suggested that gaussian splat coding may benefit from having the same information, so there should be some coordination.

Differences between JVET-AM0103 and this contribution:

• presence of the intrinsic parameters in this contribution
• the coordinate system in JVET-AM0103
• depth range
• more models for the extrinsic parameters is JVET-AM0103

There is some support for the providing a solution for this use case.

Further discussion requested after side activity to try to merge JVET-AM0103 and JVET-AM0181.

Further discussed at 1135 on 1 July 2025.

The message is renamed...

JVET-AM0013 JVET AHG report: Film grain technologies (AHG13) [W. Husak, P. de Lagrange (co-chairs), A. Duenas, X. Meng, M. Radosavljević, A. Segall, G. Teniou, A. Tourapis (vice-chairs)]

This period was reported to have been slow, with no meetings or discussions held.

From the previous meetings, the following five items should be in the second edition:

• Updated Technical Report (TR) text to fix errors and clumsy wording
• Updated tools for the TR
• Video test sequences specific to film grain to be added to the TR
• Metrics – discussion and/or survey of available techniques or metrics
• Subjective testing of Film Grain modelling methods

The following topics were suggested to be worthy of discussion for the second edition:

• Conformance – this is interesting due to Film Grain modelling being associated with SEI messages
• Film Grain Analysis methods– preprocessing analysis (parameter estimation)

The following are additional topics that could also be considered and discussed at likely lower priority:

• EG/RP documents providing guidance or usage recommendations for film grain technologies– The group is still considering what could be useful information for the industry and the scope of such documents
• Future parameters and signalling – not a v2 topic

Related contributions

Five contributions related to AHG13 were identified as of 2025-06-26.

• One contribution was the AHG report:
  • JVET-AM0013 JVET AHG report: Film grain technologies (AHG13)
• Five other contributions were uploaded at the time of the report drafting:
  • JVET-AM0085 AHG9/AHG13: On Film Grain Regions Characteristics SEI message
  • JVET-AM0124...