MaskBuilder: Converts a base MASK into a PIXEL_LOCK_MASK with three non-overlapping areas:
- hard_keep: pixels that must be preserved
- soft_keep: boundary pixels that may change slightly
- full_edit: pixels that may change freely
PixelLockSampler: KSampler-style inpaint sampler that starts from the original latent and adds noise only to editable mask regions.
PixelLockComposite: Final image-space composite. This is the node that guarantees exact RGB preservation in hard_keep.
PixelLockDecodeComposite: Convenience node that decodes a sampled latent and immediately applies the final pixel composite.

Recommended Workflow

Build a PIXEL_LOCK_MASK with MaskBuilder.
Run PixelLockSampler instead of the built-in KSampler.
Decode and restore pixels with PixelLockDecodeComposite.

PixelLockSampler protects structure in latent space. PixelLockComposite is required for absolute pixel preservation because VAE encode/decode is not lossless.

For better performance, connect a VAEEncode of the original image to PixelLockSampler's optional original_latent input. Otherwise connect original_image and vae; PixelLockSampler will encode the original image only when the lock mask has an active hard or soft area.

When replacing clothing or other large regions, start with edit_strength around 0.75-0.9. PixelLockSampler does not use an incoming empty/base latent; it always starts from original_latent or an encoded original_image, then denoises only full_edit and soft_keep according to the mask strengths.

Mask Semantics

MaskBuilder supports two base mask modes:

preserve_mask: white means preserve.
edit_mask: white means edit.

Boundary modes:

centered: soft band is created both inside and outside the preservation edge.
inward: soft band is only inside the preserved region.
outward: soft band is only outside the preserved region.

Installation

Place this folder in ComfyUI/custom_nodes/ComfyUI-Pixel-Locker, then restart ComfyUI.