SMPTE 2017: Automatic, Fast and Perceptually Accurate Gamut Mapping Based on Vision Science Models

The accompanying technical manuscript for this presentation is available here: http://ieeexplore.ieee.org/document/8...

Gamut mapping (GM) is the generic name of the procedure that must be carried out to adapt the colors of the image content to the color capabilities of the intended display technology. Most often it takes the form of gamut reduction, as in the case of cinema post-production when from the theatrical version in wide-gamut DCI-P3 a reduced-gamut BT.709 version must be created for TV/Bluray/streaming. But new and emerging displays have increasingly wider gamuts, so gamut extension is becoming a need as well, in order to appreciate the full color potential of new devices and improve the user experience. In film, GM is carried out manually by skilled technicians and it can be a very labour-intensive and complicated process, but it is preferred to automated methods (used in TV broadcasts, low-budget productions and display devices) that can't guarantee results of sufficient quality. Therefore, there is a pressing need to develop accurate, automatic and fast GM algorithms that can deal with imagery intended for conventional as well as emerging displays. We present a GM framework that allows to perform both gamut reduction and gamut extension. It is based on retinal and color perception models from vision science that involve a cascade of very simple linear and non-linear operations, like convolution with a fixed kernel (following lateral inhibition in the retina) and comparisons/thresholding (following cortical non-linearities that are key in color perception theories). The proposed method produces results that are perceptually faithful to the original content, free of spatio-temporal artifacts of any kind and that outperform the state-of-the-art, as validated both using psychophysical tests and objective metrics. These new algorithms for gamut extension and reduction are reliable and fast, and therefore have a great potential to be implemented in movie post-production suites, in cameras, in display devices, and in TV equipment for simultaneous UHDTV and HDTV broadcasts. Informational Takeaways: 1) In film, GM is carried out manually by skilled technicians and it can be a very labour-intensive and complicated process, but it is preferred to automated methods. 2) We present a GM framework that allows to perform both gamut reduction and gamut extension. Our framework is based on simple linear and non-linear operations that are inspired by retinal and color perception models from vision science. 3) Our method produces results perceptually faithful to the original content, and outperforms the state-of-the-art methods both using psychophysical tests and objective metrics.

Presented By: Marcelo Bertalmío

SMPTE (pronounced "simp-tee"), the organization whose standards work has supported a century of advances in entertainment technology and whose membership spans the globe, holds the SMPTE Annual Technical Conference & Exhibition in Los Angeles each October. The event is considered the world's premier forum for the exploration of media and entertainment technology. More information about this year’s upcoming event is available at www.smpte2018.org.

The people of the Society of Motion Picture and Television Engineers, or SMPTE, have sorted out the details of many significant advances in media and entertainment technology, from the introduction of "talkies" and color television to HD and UHD (4K, 8K) TV. Since its founding in 1916, SMPTE has received an Oscar® and multiple Emmy® Awards for its work in advancing moving-imagery engineering across the industry. SMPTE has developed thousands of standards, recommended practices, and engineering guidelines, more than 800 of which are currently in force today. SMPTE Time Code™ and the ubiquitous SMPTE Color Bars™ are just two examples of SMPTE's notable work. As it enters its second century, SMPTE is shaping the next generation of standards and providing education for the industry to ensure interoperability as the industry evolves further into IT- and IP-based workflows. Visit www.smpte.org for more information.

SMPTE's global membership today includes more than 7,000 members: motion-imaging executives, creatives, technologists, researchers, and students who volunteer their time and expertise to SMPTE's standards development and educational initiatives. A partnership with the Hollywood Professional Association (HPA) connects SMPTE and its membership with the businesses and individuals who support the creation and finishing of media content. Information on joining SMPTE is available at www.smpte.org/join.