Impact Pack - FaceDetailer Cycle Denoise

Impact Pack — FaceDetailer Cycle Denoise

A ComfyUI custom node that extends ComfyUI Impact Pack's FaceDetailer with two things upstream doesn't have:

1. A separate denoise value for every cycle pass — instead of one denoise for all cycle iterations, you set denoise_pass_1 … denoise_pass_10 individually.
2. Optional color matching — the regenerated face is matched back to the original crop before it is pasted, removing the brightness/color "seam" that appears at high denoise.

Everything else — detection, crop, feathering, SAM refinement, the detailer_hook input, the DETAILER_PIPE output — behaves exactly like the stock FaceDetailer node.

FaceDetailer (cycle denoise) appears under ImpactPack/Simple.

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Why use it

Stock FaceDetailer runs every cycle at one fixed denoise. That is a compromise: a value high enough to fix a badly generated face also destroys likeness and skin texture, while a value low enough to preserve likeness can't repair a broken face.

Splitting the value per pass lets you do things like:

| Goal | Pass 1 | Pass 2+ | |---|---|---| | Repair a broken face, then gently polish | 0.65 | 0.25 | | Disagreement recovery (nuke it, then rebuild) | 0.85 | 0.20 | | Light touch only | 0.35 | 0.35 | | Progressive refinement | 0.50 | 0.35, 0.20 |

Cycle passes are cumulative: pass 2 starts from the latent that pass 1 produced, not from the original. This is upstream Impact Pack behavior and is unchanged here.

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Requirements

| | | |---|---| | ComfyUI | Any recent version | | ComfyUI Impact Pack | Required. Installed and loadable. | | Tested against | Impact Pack 8.30 | | Python deps | None beyond what ComfyUI and Impact Pack already provide |

This node imports Impact Pack's internals (modules.impact.hooks, modules.impact.impact_pack). It is a companion to Impact Pack, not a replacement — Impact Pack must be installed.

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Install

cd ComfyUI/custom_nodes
git clone https://github.com/<you>/comfyui-impact-pack-cycledenoise.git

Restart ComfyUI completely (not just a queue refresh), then look for FaceDetailer (cycle denoise) under ImpactPack/Simple.

If the folder is missing entirely from the node list, check the ComfyUI console for:

[FaceDetailerCycleDenoise] Cannot import Impact Pack.

That means Impact Pack is not installed, not loading, or sits outside custom_nodes.

Uninstall

Delete the comfyui-impact-pack-cycledenoise folder and restart ComfyUI.

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Node reference

Inputs

All inputs are identical to the stock FaceDetailer, except:

Removed

• denoise — replaced by the ten per-pass values below.

Added

| Input | Type | Default | Notes | |---|---|---|---| | denoise_pass_1 … denoise_pass_10 | FLOAT | 0.5 | Denoise for cycle pass 1–10. Absolute values, not deltas. Min 0.0001, max 1.0. | | color_match_enabled | BOOLEAN | true | Master switch for color matching. | | color_match_mode | COMBO | mean_std | See modes below. | | color_match_strength | FLOAT | 1.0 | 0.0 = no correction, 1.0 = full correction. |

Passes beyond the node's cycle value are ignored — with cycle = 2 only denoise_pass_1 and denoise_pass_2 are read.

Outputs

Unchanged from stock FaceDetailer:

image, cropped_refined, cropped_enhanced_alpha, mask, detailer_pipe, cnet_images

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Color matching

Regenerated faces often come back slightly brighter, warmer, or flatter than the surrounding scene, which leaves a visible rectangle where the crop was pasted back. Color matching takes the upscaled source crop as a reference, re-maps the regenerated crop to match its color statistics, and only then pastes it.

The reference is captured once, before sampling; the correction is applied once, after the final cycle. Intermediate passes are never touched.

Modes

| Mode | What it matches | Use when | |---|---|---| | mean_std | Per-channel RGB mean and standard deviation (Reinhard). | Default. Fixes brightness, contrast and color cast. Fast. Can shift hue slightly. | | mean_std_luma | Luminance mean and standard deviation only, applied equally to R/G/B. | Fixes brightness and contrast while preserving the generated hue and saturation. Good for already-correct color. | | histogram | Per-channel full distribution (CDF match). | Strongest tonal match. Can flatten regenerated texture and shift hue. Slowest — involves a per-channel sort. | | lab_reinhard | Mean and standard deviation of L, a, b in CIE Lab. | Perceptually better brightness + color match than RGB. Good general-purpose step up from mean_std. | | lab_hist_luma_chroma_meanstd | Histogram match of L, mean/std match of a and b. | Strongest mode that still preserves hue. Try this if others leave a visible seam. |

Modes marked Lab require 3-channel RGB input. Anything else (grayscale, RGBA) silently falls back to mean_std.

Strength

The correction is blended with out = target + strength × (matched − target) and then clamped to [0, 1]. Lower values keep more of the generated face's original appearance; the clamp can clip highlights and shadows, so if a face looks flat or blown out, drop the strength before changing modes.

Cost

histogram and lab_hist_luma_chroma_meanstd sort every pixel of the crop, per channel. On 1024 px+ crops that is measurable, roughly doubling the cost of the detail pass. The other three modes are near-free.

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Interaction with other detailer hooks

If you connect a detailer_hook, the chain is applied in this order:

your hook  →  per-cycle denoise  →  color match

Because hooks are combined in sequence, this node's denoise_pass_* values override any upstream hook that also sets denoise, such as DetailerDenoiseSchedulerHook, SimpleDenoiseScheduleHook, or SimpleDetailerDenoiseSchedulerHook. Combining them is not an error, but the schedule from the other hook will have no effect.

Your hook's other behavior (custom sampler, noise, SEGS filtering, post_paste) is unaffected.

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How it works

Two small DetailerHook subclasses, chained with hooks.DetailerHookCombine:

• CycleDenoiseHook.pre_ksample — Impact Pack calls set_steps((i, cycle)) before each pass, then pre_ksample. The hook reads self.cur_step as the cycle index and returns denoise_pass_1..10[cur_step] in place of the inherited denoise.
• ColorMatchHook.post_upscale — clones the upscaled source crop as the reference. ColorMatchHook.post_decode — resizes the reference if needed and re-maps the decoded result.

Color maths is implemented in plain torch: Reinhard transfer, inverse-CDF histogram matching, and sRGB ↔ CIE Lab conversion with a D65 white point.

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Compatibility

doit() mirrors the argument list of FaceDetailer in Impact Pack 8.30, including newer kwargs (tiled_encode, tiled_decode, scheduler_func_opt). Two consequences:

• If Impact Pack adds a required input to FaceDetailer, this node's INPUT_TYPES() will inherit it but doit() will reject it with a TypeError. Updating this file is required.
• If Impact Pack removes or renames one of those kwargs, the call to enhance_face breaks.

If Impact Pack changes and this node stops loading, pin Impact Pack to a known-good version rather than editing the installed pack.

Limitations

• Not for video. Same as upstream FaceDetailer — a warning is logged and each frame is processed independently, ignoring temporal consistency. Use Detailer For AnimateDiff.
• Color matching uses global per-crop statistics. It cannot fix a face whose interior lighting legitimately differs from the surrounding scene; lower the strength instead.
• Matching applies to the whole crop, not a masked region.
• histogram modes assume the crop's tonal distribution should equal the source crop's. If the regenerated image legitimately has a very different tonal range (strong rim light, heavy shadow), it will be mapped toward the original — which may be the opposite of what you want.

License

GPL-3.0. This node subclasses and imports code from ComfyUI Impact Pack, which is GPL-3.0, so the combined work is GPL-3.0. See LICENSE.

Credits

• ComfyUI Impact Pack by ltdrdata — the FaceDetailer implementation and hook API this node builds on.
• Color transfer based on Reinhard et al., Color Transfer between Images (2001).