An Investigation of the Value of Wide Color Gamut in Motion Pictures

Thanks to the advancements in cinema and display technologies wider color gamuts are now possible. These technologies can support and reproduce highly saturated color content. Bear in mind, the ability to produce colors with an extremely high chroma component is strictly a capability of the technology and not a necessity that the image content must follow. In short, the decision to utilize the expanded gamut available in advanced cinema technologies is at the discretion of the creative forces behind the project. There are a number of different factors that can contribute to the creative color decisions made for motion pictures, with the primary factor being the esthetic nature of the content produced. Through creative-preference assessments of saturation adjustments in various image contents, the value of the expanded color gamut in motion picture mastering was assessed. Three images of comparable chroma histograms were utilized in the study to feature human skin tones, animated characters, and natural scenery, respectively. Upon being adjusted, each image was rendered with color content outside the boundaries of the Digital Cinema Initiatives (DCI)-P3 gamut. A two-alternative-forced-choice psychophysical study was conducted to estimate observer preference of the saturation levels in each image. From the observers’ selections, the reaction to the expanded image saturation in the three images was plotted and assessed for statistical significance. Through this study, it was found that there is a preference to incorporate colors exclusive to wider color gamuts that extend past the boundaries of International Telecommunication Union-Radiocommunication (ITU-R) Recommendation BT.709 and DCI-P3. It was also confirmed that the medium in which the content was generated influences the level of saturation preferred. Overall, this research provides a look into how technical capability and artistic vision can be connected .