Open Geospatial Consortium |
Submission Date: <2025-12-08> |
Approval Date: <yyyy-mm-dd> |
Internal reference number of this OGC® document: 25-039 |
Category: OGC® Standards Working Group Charter |
Authors: Joan Maso and Nuria Julia |
OGC GeoHEIF SWG charter |
Copyright notice |
Copyright © 2025 Open Geospatial Consortium |
To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ |
To: OGC members & interested parties
A new OGC Standards Working Group is being formed. The OGC members listed below have proposed the OGC GeoHEIF SWG. The SWG proposal provided in this document meets the requirements of the OGC Technical Committee (TC) Policies and Procedures.
The SWG name, statement of purpose, scope, list of deliverables, audience, and language specified in the proposal will constitute the SWG’s official charter. Technical discussions may occur no sooner than the SWG’s first meeting.
This SWG will operate under the OGC IPR Policy. The eligibility requirements for becoming a participant in the SWG at the first meeting (see details below) are that:
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You must be an employee of an OGC member organization or an individual member of OGC;
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The OGC member must have signed the OGC Membership agreement;
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You must notify the SWG chair of your intent to participate to the first meeting. Members may do so by logging onto the OGC Portal and navigating to the Observer page and clicking on the link for the SWG they wish to join and;
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You must attend meetings of the SWG. The first meeting of this SWG is at the time and date fixed below. Attendance may be by teleconference.
Of course, participants also may join the SWG at any time. The OGC and the SWG welcomes all interested parties.
Non-OGC members who wish to participate may contact us about joining the OGC. In addition, the public may access some of the resources maintained for each SWG: the SWG public description, the SWG Charter, Change Requests, and public comments, which will be linked from the SWG’s page.
Please feel free to forward this announcement to any other appropriate lists. The OGC is an open standards organization; we encourage your feedback.
1. Purpose of the Standards Working Group
The HEIF format is a multipart format that is defined by Moving Picture Experts Group (MPEG). In addition to camera footage, adding the georeference information, HEIF can be used to store geospatial imagery. To do that, adding the georeference information is necessary like other formats has done in the past (e.g. GeoTIFF, JPEG2000, etc). Extending this to other metadata should be possible.
A future GeoHEIF (Geographic High Efficiency Image Format) specification aims to define HEIF properties to include the georeference information in one or more image items. In addition, other HEIF properties can be added to define the semantics of dimensions and cell properties that together enable converting HEIF into a datacube container. The GeoHEIF approach was demonstrated and tested in Testbed 20 and demonstrations will continue with other approaches in Testbed 21.
The initial purpose of this SWG will be to review the work done in the Testbed 20, in particular the OGC 24-038 OGC Testbed 20 GEOINT Imagery Media for ISR (GIMI) Specification Report, as well as the work that will be done in Testbed 21 on the GIMI extensions for HEIF, bring them to the attention to the OGC Technical Committee at large and create drafts of a OGC standards that can be incorporated as part of the OGC practices.
The work should work with other SWG groups (such GeoTIFF and GMLJP2) to find an approach that can be adopted by as many formats as possible multipart. So, the work to be done is similar to the one previously done by the GeoTIFF SWG but taking into account a more open approach based on a mixture of binary sections with text sections (e.g. fragment based on JSON, turtle or XML encodings), something that was not considered at the beginning of the GeoTIFF work and was accepted by the GMLJP2 SWG.
2. Business value proposition
The HEIF format is becoming important as it has been designed to support big imagery as well as high resolution video. It is expected that in a few years its adoption will increase by the community. With the standards proposed by this group, we will ensure that georeference of imagery will not be ignored by the community and that image approaches, such as the datacubes, will be supported by the HEIF format without losing metadata. At this moment there is no format with the capabilities to export and exchange big datacubes in a single file and the HEIF is designed with capacities that can be optimal for such a purpose. This way, the format will form the basis for sharing a large existing collection of geospatial images, coverage data, animations and video, what clearly benefits some OGC members.
An approach that can be shared by some formats beyond HEIF will favour the community as no metadata lost will happen in a format transformation, reducing cost of data exchange among actors.
3. Scope of work
The High Efficiency Image Format (HEIF) format supports the storage and containment of uncompressed and compressed forms of imagery, with supporting metadata. The GEOINT Imagery Media for ISR (GIMI) establishes a number of extensions to the HEIF format that include the ContentID, TAI Timestamps and Application metadata. This SWG aims to standardize the GeoHEIF (Geographic High Efficiency Image Format) format based on HEIF, ISO base media file format (ISOBMFF) and the GIMI standards, to be used to represent orthorectified, georectified, and rectifiable imagery. In that sense, this SWG will concentrate efforts on producing an standard for geospatial metadata that can be encoded in HEIF format and other similar image formats such as GeoTIFF or JPEG2000 (the later can results in other standards done by other SWGs). Images can be geospatially enabled by providing coordinate reference system (CRS) metadata defined in Compact URIs (CURIEs), Well-Known Text version 2 (WKT2), or other OGC approved encodings. Using a raster space to model space transformation matrix, the image becomes georectified. Alternatively, a set of tie-points can be used to make the image georeferenceable. Going beyond imagery, and considering the stacked gridded variables, by adding the definition of the semantics of dimensions and cell properties, the standard supports geospatial datacubes. Both dimensions and cell properties can be continuous, ordinal or categorical.
The scope of this SWG also includes containment of imagery with a broad range of array sizes, frame rates, one-to-many components (bands), variability in color formats, bit depths and, 2D dimension, or N dimension datacubes. This is a list of use case that this SWG should consider:
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Panchromatic or grey scale imagery
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Photographic or color imagery
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Multispectral satellite imagery
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Hyperspectral satellite imagery
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Orthophotography
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Stereogram imagery
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Timeseries imagery
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Model outputs imagery of continuous or categorical variables through time
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Astronomic or planetary imagery
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Synthetic Aperture Radar imagery
Adding other metadata and annotations to the HEIF, GeoTIFF, JPEG2000 etc is an important aspect that is in the scope of this SWG.
3.1. Statement of relationship of planned work to the current OGC Standards baseline
The spirit and approach of GeoHEIF is very similar to other efforts done with GeoTIFF and GMLJP2. They specify a way to include geospatial aspects in TIFF and JPEG2000 respectively. They will be inspirational for this SWG. The result of the work of this SWG will take into account other gridded formats that can benefit from the same strategy such as GeoTIFF, GMLJP2, NETCDF, HDF, etc.
The work of this SWG is related to standards specifying services and APIs that can generate, expose or exchange geospatial coverages (such as OGC API coverages or OGC API processes) and it is foreseen that these services and API can serve GeoHEIF in the future. However, the way this is done in practice is out of scope of this SWG.
Part of the work of this SWG is related to the geodatacube SWG. The work of providing a text file format that can be embedded or accompany a gridded file will be done under the umbrella of the MetaCat DWG.
3.2. What is out of scope?
Despite the capabilities of HEIF to store video, the scope of this SWG includes still and sequence imagery but does not consider motion imagery. The SWG will not define any API to retrieve GeoHEIF and will rely on other groups to do so, such as OGC API coverage. Eventually, this SWG can collaborate with the OGC API coverage to define an extension to better support GeoHEIF in OGC API coverage after finalizing the definition of the GeoHEIF format.
The work of this SWG should build on and leverages existing HEIF, ISOBMFF AND GIMI functionality including advanced codecs, image overviews, image tiling, and metadata. Those capabilities are not separately defined by this SWG, but can be used along with the geographical capabilities defined in this SWG.
3.3. Specific existing work used as starting point
The work of this SWG will consider the OGC 24-038: GEOINT Imagery Media for ISR (GIMI) Specification Report. This document is a result of the work in Testbed 20 and was presented and approved in Rome in March 2025. This document has been written using the standards template (instead of the engineering report template) to facilitate the work of this SWG. The initial scope of this group is covered by the content of OGC 24-038. However, the group should consider additional inputs that will come from Testbed 21 that focuses on the Application Metadata capability defined in GIMI to include metadata in turtle format that can serve the same purpose but in a different way.
There are other documents result from the work of Testbed 20 about the same topic that can be useful for this SWG:
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OGC 24.039r1: OGC Testbed 20: GIMI Lessons Learned and Best Practices Report
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OGC 24-040r1: OGC Testbed 20 Coverage Format Selection Report
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OGC 24-042r1: OGC Testbed-20 GIMI Open Source Report
4. Description of deliverables
The main deliverable of this SWG is an OGC standard that specifies a common way of adding georeference to images and image sequences as well as how structure this images into a datacube. In addition, an OGC standard should specify GeoHEIF that will describe specifics on how to include the common way to include this type of metadata in HEIF. An additional document can be released as a second part of the standard discussing how to encode other metadata and annotations in the format.
4.1. Initial deliverables
The initial deliverable of this SWG is an OGC standard that specifies a common way of adding georeference for images and image sequences and how structure this images into a datacube. This way will be compatible with the HEIF and the GIMI specifications.
4.2. Additional SWG tasks
This SWG will collaborate with OGC API coverages SWG to ensure that GeoHEIF can be served by the web API
This SWG will collaborate with GeoTIFF SWG, GMLJP2 SWG and other SWGs dealing with gridded formats to ensure that the common way of adding metadata can be accepted by those relevant formats. This may include generation of a logical model for georeferencing, and specific encodings of that logical model that are consistent with the underlying raster or coverage format.
This SWG will consider generating educational materials and guidelines on GeoHEIF and to create a GeoHEIF website to include them as well as listing applications and implementations of GeoHEIF.
6. Anticipated audience / participants
We expect participation of people interested in gridded coverage formats, such as remote sensing experts as well as participants interested in encoding geospatial datacubes in files, for example modelers of environmental variables (a.k.a observed properties) such as weather, climate and oceans experts. We also expect that GIMI community will collaborate in this SWG.
7. Domain Working Group endorsement
The GeoTIFF SWG is the initial group where the creation of this SWG is discussed. We would like to request the endorsement of the MetaCat DWG
8. Other informative information about the work of this SWG
8.1. Collaboration
The OGC supporting infrastructure is in the process of evolution to new technologies and it is difficult to predict the working environment at this point. We expect to use GitHub to develop the standard in asciidoc format (and metanorma) as well as the GitHub issue tracker to manage content and change requests. The group will internally discuss if making the GitHub repository public is acceptable by all parties.
8.2. Similar or applicable standards work (OGC and elsewhere)
The following Standards and projects may be relevant to the SWG’s planned work, although none currently provide the functionality anticipated by this committee’s deliverables:
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GeoTIFF
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GMLJP2
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O&M and SOSA
The SWG intends to seek and if possible maintain liaison with each of the organizations maintaining the above works.
8.3. Details of first meeting
The first meeting of the SWG will be held immediately after the approval of the charter (this document) in OGC meeting in Boulder in October 2025. Call-in information will be provided to the SWG’s in the OGC Agora in advance of the meeting.
8.4. Projected on-going meeting schedule
The work of the SWG will be carried out primarily by discussions in the OGC Agora, GitHub issues and conference calls, possibly every month, with face-to-face meetings at some of the OGC Members Meetings.
8.5. Supporters of this Charter
The following people support this proposal and are committed to the Charter and projected meeting schedule. These members are known as SWG Founding or Charter members. The charter members agree to the SoW and IPR terms as defined in this charter. The charter members have voting rights beginning the day the SWG is officially formed. Charter Members are shown on the public SWG page. Extend the table as necessary.
Name |
Organization |
Joan Maso |
UAB-CREAF |
Nuria Julia |
UAB-CREAF |
Brad Hards |
Silvereye Technology |
Jim Autonisse |
WiSC Enterprises, LLC |
Chuck Heazel |
Heazeltech |
Don Sullivan |
NASA |