© ISO Focus, www.iso.org/isofocus ISO and the Media

Digital photography has not JPEG – replaced traditional chemical photogra- phy, but rather given photographers new Still photography creative tools and many new modes of brought to life printing. It has also contributed to the progress of e-commerce, where digital images of products and services offer new merchandising opportunities. by Daniel T. Lee, Convenor, One enabler of this phenome- ISO/IEC JTC 1/SC 29/WG 1, non is the availability of powerful and Coding of still pictures inexpensive digital cameras. Less vis- ible to consumers, but nonetheless key, haring over the Inter- is the JPEG imaging standard – a joint net has become one of the most project between ISO and the Interna- Sinteresting modes of social inter- tional Telecommunication Union’s Tel- action since the advent of modern dig- ecommunication Standardization Sec- ital media. tor (ITU-T). The JPEG standard, ISO/ Millions of images are shared IEC 10918-1 or ITU-T recommendation every day among friends and family in T.81, giving requirements and guide- e-mails, photo-hosting Web sites and lines for digital compression and cod- the enormously popular social network- ing of continuous-tone still images, was ing sites, like MySpace, Facebook and approved in 1992. , where users can even instantly upload photos taken with their mobile phone cameras. Digital photos are also widely printed at home or through commercial printing services.

ISO Focus April 2009 15 © ISO Focus, www.iso.org/isofocus

Main Focus

Recipe for success JPEG 2000 makes use of sev- JPEG 2000 provides a rich set eral advances in compression technol- of technology. Since its publication, The Joint Photographic Experts ogy (including transform) to the standard has been successful in Group – also known as the JPEG com- deliver superior compression and sys- areas such as digital cinemas, security mittee – is the name used for working tems performance, providing many applications, video surveillance, defence group WG 1, Coding of still pictures, advanced features in scalability, flex- imaging, , medical imag- under ISO/IEC JTC 1/SC 29, Coding of ibility and systems functionalities that ing, digital culture imaging, broadcast audio, picture, and hyper- outperform its predecessor. applications and 3D . The work media . The “J” in JPEG After publication of the first six of JPEG 2000 is continuing with tech- refers to the joint development work parts of the JPEG 2000 standards, which nology maintenance, and work on a between ISO and ITU-T. included the core, extensions, motion, new part to address the XML interface The baseline technology was conformance, reference software and to JPEG 2000 objects. based on a simple, efficient 8 X 8 dis- multi-layer compound image , crete cosine transform compression algo- the JPEG committee began investigating rithm that uses , oper- four important application areas. The ated in sequential mode and restricted Misplaced image ? resulting four parts addressed security to 8 bits per input. (JPSEC), interactive protocol (JPIP), While advances have been made Besides its technical merits, the multi-dimensional datasets (JP3D) and on many fronts in search engine success enjoyed by JPEG can be attrib- wireless applications (JPWL). technology, the area of image search has uted to the availability of free and effi- met some limitations. cient software developed by independ- When entering a key word in a ent groups, such as the Independent “ JPEG 2000 makes typical search engine, users will often JPEG Group. Part of its success was use of several advances find the results unsatisfactory, either also due to the introduction of the JPEG in compression technology because the wrong image is retrieved file interchange format (JFIF), and lat- or the desired context is not accurate- er the exchangeable image file format to deliver superior ly interpreted. () that make the popular file exten- compression and systems These limitations are partly due sion .jpg synonymous with JPEG com- performance.” to lack of standardization in the fol- pressed images. lowing areas : Since the publication of the JPEG standard, the JPEG committee has con- • Ability to reuse (lack of tinued to work to deliver innovative interoperability of metadata) imaging standards that can serve new About the author requirements, using the most advanced • A common query format and search technology from research in the imag- Daniel T. Lee semantics for image search ing field. (BS Cornell, MS PhD • A common format for handling con- Stanford) is a text in image search. A new generation – seasoned tech- Other aspects that need to be JPEG 2000 nology execu- tive with more addressed include how metadata can A number of imaging applications than 25 years of be created, modified and stored, and were not addressed when the original experience in also how image collections can have JPEG standard was published. These the high tech metadata different from that of a sin- include high resolution imagery, digital industry. He is gle image. The JPEG committee there- libraries, cultural archives, high fidel- the General Manager of eBay Global fore started a new work item to address ity colour imaging, wireless, medical Development Centers. Prior to eBay, he these problems. imaging and digital cinemas. was the Chief Technology Officer of Organized into five parts, Part 1 All these applications require Yahoo! Asia. Before that he was with of ISO/IEC 24800, Information technol- Hewlett Packard, where he held a enhanced functionality from a com- ogy – JPSearch, was published in 2007. number of management positions in pression standard, which JPEG does It provides a framework for interopera- Imaging Technology. He also worked at not satisfy due to design points that Advanced Telecommunications Research bility for still image search and retriev- were beyond its scope when it was (ATR) in Japan and at IBM Research. In al, specifying two related items. developed. The committee therefore standardization, he serves as Convenor The first is a framework for started a new work item to address of the JPEG standards committee, ISO/ interoperability for still image search these issues, resulting in the JPEG IEC JTC 1/SC 29/WG 1, Coding of still and retrieval. The second identifies the 2000 family of standards – the ISO/ pictures, a position he has held since architecture and the components in this IEC 15444 series (JPEG 2000 image 1996. framework, the linkages between com- coding system). E-mail: convener@.org ponents, and which of these compo-

16 ISO Focus April 2009 © ISO Focus, www.iso.org/isofocus ISO and the Media

nents and links are to be standardized The ultimate goal is to maintain in JPSearch. full image fidelity and precision and The image search and retriev- avoid intermediate data corruption due al framework is determined by actual to insufficient represen- use cases, leveraging the experience of tation of image data in high-dynamic text retrieval where, for example, dif- range imagery settings. ferent users issuing the same query may JPEG XR is designed to optimize be looking for different results. The and compression efficien- JPSearch framework is general enough cy while also enabling low-complexity to support many possible approaches to encoding and decoding implementations. image retrieval, e.g., from using only ISO/IEC 29199, Part 2, giving the spec- low-level image features, to text anno- ification of JPEG XR, is expected to be tations, to community input, or a mix- published sometime this year. ture of such approaches. The other parts, which are still under development, will be: Triumph of innovation and teamwork • Part 2 : Registration, identification, and management of schema and The JPEG committee is proud ontology of the success of the imaging stand- ards it has developed over the past 20 • Part 3 : JPSearch query format years. The JPEG standard is used every day by millions of people to share and • Part 4 : File format for metadata print digital photos. The adoption of embedded in image data (JPEG and JPEG 2000 in a wide variety of imag- JPEG 2000) ing applications is a mark of its suc- • Part 5: Data interchange format cess. The work of JPSearch will propel between image repositories. growth in image search and retrieval systems, and JPEG XR will address the need for high-dynamic-range imagery Full image fidelity still to come. The latest work item initiated by the JPEG committee is the JPEG XR “The JPEG standard standard, ISO/IEC 29199 (JPEG XR is used every day image coding system), also in five parts. The overall goal of JPEG XR is to sup- by millions of people to port a wide range of colour encoding for- share and print digital mats, especially in high-dynamic-range imagery settings, where the associated photos.” numerical range, colour fidelity, col- our and precision are maintained The JPEG family of imaging using a variety of fixed and floating- standards is indeed a triumph of inno- point numerical representations. vation and teamwork. Under the inter- JPEG XR addresses the needs of national standardization process, the high-dynamic-range applications that are best minds in image coding technology beyond the common usage of standard gather from all over the world in a con- baseline JPEG, which uses 8-bit repre- sensus-driven process to develop com- sentation. It supports a variety of col- prehensive image coding systems. our profiled pixel formats using integer representations in bit depths of 8 to 16, while maintaining full compatibility with existing legacy devices. In addition, JPEG XR supports a number of advanced pixel formats to avoid some of the limitations and complexities that result when convert- ing between different, range-limited, unsigned integer representations.

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