Uniformity Measure for French Cinema
Date & Time
Tuesday, October 22, 2019, 3:00 PM - 3:30 PM
Topic header: Uniformity measure for projection and direct view display
Keywords: Movie projection systems; Movie direct view displays; Norm; Uniformity measure;
Practical standard paper
This paper is about a practical uniformity measure defined for a national standard.
French cinema theaters are following strict rules; there are two norms involved when according theater operation license. One norm is about architectural considerations, the other about movie reproduction parameters. The main goal of these specifications is to ensure that movies are reproduced uniformly in all theaters while matching the intention of the creative team during final check. Another goal is to allow a satisfying perception by the audience, trying to avoid unnecessary physical or audio-visual stress.
These two norms are currently under periodic revision. The specifications listed in the norm about movie reproduction is including uniformity formula.
The validity of this uniformity formula was questioned by some counterexamples. A new uniformity measure is under study.
The proposed method is unifying projection and display systems in the same measure. Projection vignetting effect is cancelled using current room and screen dimensions. The formula is also independent of the reproduction system dynamic range.
Nine locations on screen are used as points of measure.
The proposed measure of uniformity is based on the statistical measure called the K-L distance. It is comparing current results with a standard statistical distribution. The type of distribution is chosen based on practical consideration.
Calculations are simple enough and are implemented in a spreadsheet
1. The vignetting effect, inherent to projection systems, is cancelled using a simple approximation, giving the same valid measure for projection and direct view display.
2. The distribution of measure values, eventually corrected, is compared to a standard distribution, giving a single estimator, i.e. the K-L distance. For practical reasons, nine locations are chosen on screen.
3. Uniformity estimator value is used to categorize the actual reproduction in few quality classes. The complementary maximum luminance deviation value is used normatively to accept or reject the current room performance.
Technical Depth of Presentation
What Attendees will Benefit Most from this Presentation
Managers, Technologists and Engineers
Take-Aways from this Presentation
Method for uniformity measure in theaters