I am working on a logic design project architecture involving ACES AP0 and am looking for the following questions solution:
A. How are the different colors mapped into the FP16 values in ACES AP0. Is there a Spec for Hardware bit mapping between the primary colors and AP0 range ? I understand the ST-2065-1 spec maps its floating point 16bit range of -65K to +65K into actual color values. I am looking for a Spec on this mapping.
B. I understand ACES AP0 primaries uses a range from -64K to +64K which is different from a typical 0 to 1 mapping for each primary. If i were to translate these primaries into a logical bit values, what would be the purpose of the negative range ? Is there a Spec to translate these to 0 to 64K or should i use a subset of the range to represent the AP0 primaries ?
I do not intend to use an ODT, i plan to study and plot things in actual AP0 primaries and with Hardware and not the Software flow. An ACES Spec which states these mappings and translation would be useful.
What ist your usecase or application exactly?
Remember ACES is designed for motion picture workflows.
The use-case is very limited for present day scope due to almost non-availability of panel hardware that can actually display the range of colors as depicted by ACES.
The application project i am working on is a flow as would be mimicking the hardware processing pipeline all the way from reception of a compressed frame/frames, processing the frame data and a final output in terms of FP16 ACES Color primaries.
The intent is to look at the pipeline from a perspective as if the final pixels were supporting more colors than the current day RGB.
From what i am missing is a Spec that maps the FP16 ACES range of -65K to +65K to actual color primaries. I would like to analyze the FP16 ACES output of for example a compressed frame/frames after some fixed function processing, throughout in AP0 workspace in hardware.
I do agree that ACES is designed for motion picture workflows but, the mapping of FP16 to color primaries, i assume would still exist as a Spec ?
ACES AP0 is fundamentally scene-referred, I think it makes little sense to build a hypothetical processing pipeline for a display because AP0 data is not meant to be viewed.
Sure that sounds appropriate.
I had one last question if you could help me understand.
Lets say as you mentioned AP0 is not meant to be viewed and considering pipeline for display is a based on a hypothetical assumption. Keeping the use-case aside, even on the present day workflow, the Workspace of operation seems to be AP0. In that case be it even Software processing through different Apps/Software, there should be an existing mapping of the floating point inputs to ACES Color primaries. Could you help me understand that mapping ?
I have difficulties understanding your question.
What do you mean by
floating point inputs?
Are you talking about a camera input now?
AP0 is defined via the 1931 Observer so you can trivially map any 1931 based input space into AP0 by using a 3x3 matrix.
Maybe you can elaborate a bit more on what you are trying to achieve.