Chromaticity Diagram Plugin for Davinci Resolve, Adobe After Effects and Adobe Premiere

HDR Chromaticity Diagram Plugin for Dvinci Resolve, Adobe Premiere and Adobe After Effects.
HDR Chromaticity Diagram Plugin for Davinci Resolve, Adobe Premiere and Adobe After Effects

 

With this plugin, you’re adding a the ability to monitor using a CIE diagram to your productions. It covers BT.2020, DCI-P3, BT.709 and Adobe RGB. The diagram will help you to see how much of the color gamut you’re using and if you’re exceeding the legal colors of the specified gamut. Working with the BT.2020 container in particular, it’s important to manage necessary limitations and see if you’re using legal colors or not.
The plug-in will show you the xy or u’v’ coordinates of the pixels in your video!

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Controls: Preset Section

In this section, you’re able to save and open presets for the appearance and calculation basis of this plug-in. Several presets are delivered with the installation of the plug-in.

Controls: Area Selection

If you want to apply the chromaticity analysis to a specific section of the frame instead of analyzing the whole frame, you’re able to do so here. The size and position of the analysis window can be defined.

Controls: Color Space Configuration

In order to calculate all color coordinates correctly, you need to define some parameters of your footage here.

The selection for the container contains the options BT.2020, BT.709, sRGB, Adobe RGB, DCI-P3 (D65) and DCI-P3(D60). For most of the current HDR productions, you’ll need to select BT.2020 and then see if the P3 gamut within this container is exceeded or not.

The EOTF selection allows you to pick in between HDR (PQ/ST.2084), HDR (PQ/BT.2100), SDR with adjustable gamma and peak luminance or HLG. One of the reasons why this EOTF option is relevant for the Chromaticity Diagram is that you’re able to ignore specific ranges of Luminance or Lightness (L*u’v’) in the diagram. You’d do that if you don’t want the diagram to include areas of low noise or clipping. The BT.2100 option follows the flavor of several post-production tools to dedicate the full range of available values to only a part of the possible dynamic range of PQ. For most HDR productions, ST.2084 should be the best option.

The checkbox “Use Full Range” decides if the plug-in calculation is using or ignoring signal levels above legal white and below legal black. Please note that deselecting of “use full range” might result in ignoring some existing signal levels, even if your delivery is in the video range. Depending on your project setup regarding signal ranges, using full range might make sense even if your final delivery is a video for the end consumer (always in narrow/video range).

Controls: Overlay Information

The general look and feel of the diagram overlay to your video is defined here. You may adjust the size and position as well as background and graticule colors. The option for Overlay Quality becomes relevant at bigger diagram sizes only – it improves the resolution of the diagram.

Controls: Diagram Options

In the diagram options section, you’re able to select in between CIE 1976 or CIE 1931 diagram modes as well as zooming into areas of interest (e.g. the area around the white point). Defining interval values for the diagram as well as Minimum and Maximum values for Luminance or Lightness provide further customizability.

CIE 1976 Diagram (u'v')
CIE 1976 Diagram (u’v’)
CIE 1931 Diagram (x,y)
CIE 1931 Diagram (x,y)

Controls: Reference Data

Here you can hide, show or change the appearance of some reference data in the diagram. Reference Data includes the diagram legend, the different gamuts, the D65 white point and the spectral locus.

Q&A

Question: Does the plug-in analyze the image input from the node it is applied?

Answer: The plug-in node should be placed right before the output, We suggest making it a timeline node. Multiple of our analyzer plug-ins can be placed in parallel nodes and then allow multiple types of analysis at once. Since we have not officially released those other analyzers yet, we can keep this answer related to the chromaticity diagram. In a color managed workflow, the diagram options must be set to the same properties like the Output Color Space in Resolve. Of course that is only possible for those options that are existing within the options of the plug-in. If you’re working within BT.2020 or BT.709 or DCI-P3, you’re fine because the plugin supports it. If you’re working within a camera gamut in the output color space, the results won’t be correct. One of the main scenarios where the plug-in is useful should be the BT.2020 Color Space, where production monitors may support the container but not the primaries. In such case, you want the colors to fit the P3-part of BT.2020 and see how much of it you’re using.

BTW: The same analyzer (chromaticity diagram) is available in our standalone app HDRmaster v2 and the upcoming HDRmaster 8K as well, so that’s where the final delivery to the customer can be checked for the distribution of colors within the encoded BT.2020 files for example.

Question: Does the plug-in support ACES?

Answer: We’ll be adding experimental ACES with the next update (free for all customers). Experimental means I think at this point it should just be another input matrix in the existing algorithms but I’d like to confirm with someone who’s working in ACES on a regular basis to make sure we’re not missing out any important aspect. The diagram plug-in has options for different transfer functions, so specific ranges of luminance (like low noise area) can be excluded. This seems to be a little bit more challenging when ACES with many OETF options comes in. We might just change the range slider from luminance to a percentage in that case to have a good solution.

 
 

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