DMAG JPEG activities (DMAG-JPEG)

February 2009 - December 2021

Project description

Since the end of 2008, DMAG group has been working with the ISO/IEC JTC1/SC29/WG1 (JPEG) group.

Most of the contributions have been focused on the JPSearch standard (ISO/IEC 24800), which main aim is to define a reference architecture for digital image search systems, as well as a join of universal interfaces for accessing to them. The standard puts a lot of effort on solving the problem of metadata formats heterogeneity. On the one hand, JPSearch specifies (in its Part 2) the JPSearch's Core Metadata Schema, a basic language of image metadata which contains the common elements of the most popular formats, and its role is to be the reference format for the acknowledgment between systems users of heterogeneous formats. On the other hand, the standard provides (also in its Part 2) the JPSearch Translation Rules Declaration Language (JPTRDL), which makes it possible to define and publish translations between different metadata languages. The definition of the translations from and to the JPSearch’s Core Metadata Schema minimizes the number of necessary translations. The other parts of the JPSearch define: A query language (Part 3), a format for embedding metadata in the image files (Part 4), a format for the synchronization of image databases (Part 5) and reference software (Part 6). Part 1 has informational purposes and describes the general structure of the standard. The influence that DMAG has had in the final version of the JPSearch demonstrates the fact that the two participating researchers (the professors Jaime Delgado and Rubén Tous) are co-editors of the parts 1, 2, 3 and 6 of the standard and that the main part of the reference software (in the part 6 of the standard) has been developed by the DMAG.

JPSearch RA
In 2011 the SC29/WG1 approved the assignment of the ISO Registration Authority (RA) of the JPSearch to the DMAG of the UPC. In order to set up the JPSearch and achieve an extensive use, it is necessary, as Part 2 describes, that an international registration authority exists which will be in charge of registering, identifying and publishing schemas of image metadata and their associated translations so that they can be queried for whatever JPSearch compliant system. Following the ISO directives, the JPSearch RA will provide a registration mechanism so that any person or organization can request the incorporation of a new metadata scheme or a new translation between metadata schemes.
Nowadays, there are 60 registration authorities of the ISO, from which only about 20 are for TIC standards. Among those, more than half are in charge of international organizations with headquarters in some countries. The rest are in USA, Japan, UK, France, Germany, Denmark (only two), Canada (only one) and Holland (only one). Just one of them (that from the ISO/IEC 10036 standard) is managed by a university (the International University of Japan). That is to say, none of the currently working ISO and ISO/IEC RAs is managed by a Spanish organization, which is an added value.

JPEG ontology for still image description (JPOnto)
Recently, within the context of JPSearch, the WG1 group has initiated a new activity on future generation image metadata. The main goal of this activity is to provide a simple and uniform way of annotating JPEG images with metadata compliant to the Linked Data principles. Linked Data is a method of publishing metadata so that they can be interlinked among them, to public Linked Data databases (e.g. DBpedia) and to formal vocabularies, i.e. ontologies. An ontology is a specification of what terms to use for a certain domain, and how these terms are defined. Modern ontologies have transitioned from shared natural-language definitions to shared machine-processable representations, usually under the shared formal model provided by RDF. The WG1 group has also launched a systematic review and consolidation of its file formats and codestream syntax with a view to consolidating the benefits of the JPEG system of standards and enabling new functionalities. Ontology technologies are expected to play an important role in this effort.

DMAG activity

Nowadays, the DMAG group is leading some new initiatives in the WG1. On the one hand, the standardization process of the JPEG Visual Ontology and the JPEG Linked Data has been started. Both activities have as main goal, the embedding of standardized semantic metadata inside JPEG and JPEG2000 image files (for instance, annotate information about people who appear in the image, their actions, events, objects, etc). The specification of a unified ontology for the description of image contents would ease the reuse of this kind of metadata in multiple environments, such as searchers, mobile visual searchers, social networks, picture managing applications, and evaluation environments of computer based vision systems. On the other hand, the DMAG group is also involved in a new activity related to the protection of the privacy in digital images. This activity also considers the protection of the metadata embedded in the images.