Classic color systems, such as Munsell and Ostwald, relied upon a three dimensional model of color to visually conceptualize the color order, in the shape of a cylindrical atlas and a double cone, respectively. These systems can aid in designating absolute values and identifying manufacturing standards to numerical specifications.
However, the addition of multiple color targets, including wide-color-gamut (WCG) and high dynamic range (HDR) to motion picture deliverables, now means that multiple versions of the same file will be delivered. A cohesion between assets is required, whether or not that is done with metadata in the case of Dolbyvision files, or with completely separate image sequences as may be the case with some providers. Using a numerical color order system does not help QC professionals, color pipeline engineers, or production creatives determine whether these multiple versions are in line with original creative intent.
The paper proposes a visual color navigation system, which provides new vocabulary in order that shifts in color, lightness, or chrominance values be identified and shared between creatives and engineers alike in motion picture applications. The system revolves around a hue disc with four cardinal directions, indicating two axes of warmth to coolness (North-South and East-West). This color compass can be used as a navigational tool within any color encoding scheme or color space in use for a project. For example, the system can be used to discuss the g and j axes in OSA-UCS, the a* and b* axes in CIELAB, or the Tritan and Protan axes in ICtCp. The system also equates lightness to altitude values, so a user can describe “higher” or “lower” values as one might describe the altitude of terrain. Lastly, chrominance will be described as expanded or contracted, in relation to the original value.
The paper will include illustration of the system at work in different color spaces, in addition to using practical examples from the author’s experience with over one hundred episodes of HDR content.
Technical Depth of Presentation
The technical depth of this presentation is fundamental. It will describe some foundational information of how color is quantified in various systems, such as CIELAB and ICtCp, in addition to history of color order systems. It will also provide foundational information on film language and applied color practice.
What Attendees will Benefit Most from this Presentation
The audience for this paper is color scientists/QC professionals who wish to communicate with less technically-versed creatives. Simultaneously, another key audience for the paper is creatives who wish to communicate with more technically-versed color scientists/QC professionals. The system aims to build uniform qualitative color designations for any imaging professional whose work involves multiple target color volumes or color encoding schemes. This language can be used to describe either artistic or technical limitations and challenges.
Take-Aways from this Presentation
The most important takeaway from this paper is first: qualitative vocabulary for communicating shifts in hue in practical applications. From this, readers will be able to evolve their descriptions of hue changes from the generic “warmer” or “cooler” to more fine-tuned and specific terminology. Secondly: readers will be informed about the type of hue shifts that may occur from improperly managed color encoding schemes or color spaces. Thirdly: readers will have a refresher of the history of color order systems and how those systems have evolved.