fix(image): correct HLG inverse-OETF clamp in hlg_to_linear

[bigcat88]

hlg_to_linear (Save Image (Advanced), input_color_space=HDR) clamped its exp branch at _HLG_C (~0.5599) instead of the 0.5 branch point. Every HLG signal value in (0.500, 0.560] therefore produced the constant 0.10706 instead of the 0.0833->0.1071

Without patch

With patch from this PR

Additional data

wf_plus_input_image.zip

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Run ID: e08a2b12-c381-4f73-a920-56f84c08bce6

📥 Commits

Reviewing files that changed from the base of the PR and between 3fe9f5f and 611c728.

📒 Files selected for processing (1)

• comfy_extras/nodes_images.py

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📝 Walkthrough

Walkthrough

This change adjusts the hlg_to_linear function in comfy_extras/nodes_images.py. The clamping applied to the input of the log-branch exponential computation is changed from clamping at _HLG_C to clamping at the branch split point 0.5. The torch.where selection logic determining which branch's output is used remains unchanged.

Changes

File	Change
comfy_extras/nodes_images.py	Adjusted clamp bound in high-branch computation of hlg_to_linear from _HLG_C to 0.5

Related issues: None specified.

Related PRs: None specified.

Suggested labels: bug, image-processing

Suggested reviewers: None specified.

Poem: A rabbit tweaks a clamp so small,
From _HLG_C to point-five it falls,
The log branch now stays sane and bright,
No infinite glow to spoil the night,
A tiny hop, a fix worth all. 🐇✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main fix to hlg_to_linear's HLG inverse-OETF clamp.
Description check	✅ Passed	The description directly explains the HLG clamp bug and shows the expected before/after behavior for this patch.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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