SMPTE 2018: Visual perceptual entropy measure

This paper is about a theoretical framework on perceptual reproduction quality assessment. — Visual perception is the main theme for two approaches on image metrics, visual performance and image quality. Visual performance looks at the perception of standard elementary images, such as gratings, by different observers or by a single observer in different visual conditions; image quality looks at the perception of variations of the same complex scene by a standard observer. — Visual performance, for which Barten proposed a model in 1999, is studying threshold responses in visual perception. For image quality, on the other hand, indexes are built which must evaluate responses to a variety of suprathreshold visual characteristics, attempting to give results as close as possible to human visual perception. — In audiovisual field, all the configurations approved by the creative team must be reproduced in the final viewing. This cannot be measured by visual performance or image quality indexes. A third approach is needed. This may be called perceptual reproduction quality assessment. Visual perception assessment is not measuring defects, per se; it is built to evaluate the perceptual effectiveness of a given scene coding through a given reproduction technology. — It is only dependent on the number of configurations being reproduced by a given theater system relatively to the various configurations reproduced and approved in the review room. As such, it is a statistical measure. It is in fact similar to the definition of relative entropy. One important fact is that this evaluation must include a model of visual perception. — This paper shows how relative entropy, and entropy loss, can be estimated while taking into account the coding transform, the projector performances, maximum light and the characteristics of human visual system. — This scheme is carried easily for monochromatic content. Color, trichromacy, is quite challenging. The size of configurations goes from 2 12 to 2 36 , around 6 billion configurations. Calculation and memory requirements are huge. Non-linearities are adding complexity leading to calculation of an upper limit only of entropy loss. — Presentation of results is also a challenge. One way to solve this is to process separately lightness and chromatic information. Read full paper at: https://ieeexplore.ieee.org/document/... Presented By: François Helt 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. #SMPTE #VisualEntropy #TechnicalConference