Page 109 - ITU Journal, ICT Discoveries, Volume 3, No. 1, June 2020 Special issue: The future of video and immersive media

ITU Journal: ICT Discoveries, Vol. 3(1), June 2020

Fig. 2 – JPEG Pleno intends to support the full E2E chain of a plenoptic system. Acquired or generated plenoptic data and associated metadata is being
compressed and packaged by the JPEG Pleno encoder and subsequently stored or transmitted. Thereafter, this data is depackaged, decoded and rendered
to be reproduced by e.g. a 3D/holographic printer or plenoptic display. Alternatively, the data can be consumed/analyzed by an autonomous (AI) system.
Note that the JPEG Pleno framework also facilitates conversion to other modalities throughout the E2E chain.

3. REQUIREMENTS • low encoding and decoding complexity in terms of
computational complexity; memory complexity and
Following the use cases identified in the previous section,
parallelization (SO);
the JPEG Committee has identified the relevant require-
• privacy and security guarantees (SA);
ments for the JPEG Pleno project. These requirements
• support for parallel and distributed processing (SO);
have been classified either as generic requirements, in
• low latency and real-time behaviour (SO);
the sense that they simultaneously apply to light field,
• support for hierarchical data processing (SO).
point cloud and holography modalities, or specific re-
quirements in the sense that they are relevant only for one
The more plenoptic imaging specific requirements are:
of these modalities. While the mandatory requirements
• minimal number of representation models for the
are stated with a ‘shall’ (SA), the optional requirements
various plenoptic modalities (SO);
are stated with a ‘should’ (SO).
• content description/metadata tools for efficient
search, retrieval, filtering and calibration of content
3.1 Generic requirements
from the various imaging modalities for all plenoptic
The most recent JPEG Pleno generic requirements are modalities (SA);
listed in the JPEG Pleno Call for Proposals on Light Field • signalling syntax to enable sharing of content be-
Coding, issued on January 2017 [8]. Many of these tween different displays or display elements (SO);
generic requirements are common in coding standards, • JPEG ecosystem appropriate degree of forward and
although a few of them are JPEG or plenoptic imaging backward compatibility (SO).
specific; further details for both of them may be found
in [8]. 3.2 Light field specific requirements
Regarding the specific light field requirements, the
The common coding requirements are:
JPEG Pleno Call for Proposals on Light Field Coding [8]
• high dynamic range, wide colour gamut, colour
enumerates the following features:
space, transparency and opacity representation
(SA);
• Representation format – shall support a relevant
• highest possible compression efficiency (SA);
set of spatial and angular resolutions, multiple
• near-lossless and lossy coding up to high quality
colour/spectral components and 6 degrees of free-
(SA);
dom (6-DoF); furthermore, should support capture
• lossless coding (SO);
and display dependent/independent light field rep-
• compression efficiency/functionality tuning (SO);
resentation, and a universal light field representa-
• random access to subsets of the complete com-
tion;
pressed image data with fine granularity (SA);
• quality (SNR), spatial, depth and spectral resolution, • Calibration model in metadata – shall support the
number of viewing angles, viewing angle range com- signalling of a calibration model in metadata to en-
plexity and content (object) scalability (SO); able correct content transformation in the imaging
• editing and manipulation such as change of depth of pipeline;
field, refocusing, relighting, viewpoint change, navi-
gation, and enhanced analysis of objects (SA); • Synchronization of data between sensors – should
• error resilience for a large set of networks and stor- support signalling syntax to enable synchronization
age devices (SO); of content captured by different sensors;

© International Telecommunication Union, 2020 87