Could you clarify the exact color space, primaries, and transfer function of the HdrColor annotator output of omniverse replicator?

Omniverse Core Platform RTX Renderer
,
1

Operating System:
Linux(ubuntu 22.04.5)
Kit Version:
107.3 (Kit App Template)

omni.replicator.core-1.12.10+107.3.0.lx64.r.cp31
Kit Template:
Custom

cat > playback.toml <<‘EOF’
[kit_base_editor]
application_name = “omniverse.editor”
application_display_name = “Omniverse Editor”
version = “0.1.0”
selected_layers =
EOF
./repo.sh template replay playback.toml
GPU Hardware:
GeForce RTX 5090 (Blackwell architecture)
GPU Driver:
570.172.08
Work Flow:

Rendering HDR images using Omni.Replicator with the HdrColor annotator.
Main Issue:

When generating images using the Replicator API and an omni.replicator.core.Writer configured with data_structure="annotator", I need to determine the exact color space (primaries + transfer function) used by the HdrColor annotator.

I can confirm the values are scene-linear, since the pixel values in the EXR range from approximately 4.59e-06 to 4.50, but I cannot determine which scene-linear color space is being used.

Based on common practices, I suspect either:

  • Linear Rec.709, or

  • Linear ACEScg

…but I cannot find documentation confirming this.

Why I Need This Information:

I am converting the EXR output from the HdrColor annotator into JPG/PNG (sRGB).
To perform correct conversions, I need to know:

  • which scene-linear color space the EXR is encoded in,

  • what primaries it uses,

  • whether any OCIO transforms are applied internally,

  • whether Replicator uses ACEScg or Rec.709 as its default rendering space.

Without this information, converting linear EXR → JPG/PNG causes color shifts, incorrect gamma and mismatched saturation.
Reproduction Steps:

  • Use Replicator with data_structure="annotator".

  • Enable the HdrColor annotator.

  • Render EXR frames via omni.replicator.core.OmniverseRender.

  • Inspect pixel values (linear).

  • Attempt color-space identification during EXR → JPG conversion → results unclear.

  • Attempt to determine color space → unclear which linear space is used.

2

Thanks for the question. It is Rec.709