Filter Ops (live-preview)

Filter Ops is the grab-bag node of the ComfyUI Channel Ops pack: eleven classic image effects behind one node - Blur, Halftone, Color Filter, Sharpen, Pixelate, Posterize, Vignette, Levels, Color Balance, Laplacian Sharpen, and Unsharp Masking. The pitch is that instead of installing six different post-processing packs, you get the effects that actually get used in one dropdown.

The genuinely useful part isn't the list, though - it's the UI. The node's widgets are adaptive: pick "Vignette" and only the vignette controls appear; pick "Levels" and you get a histogram widget with black/white/gamma handles you can drag. The node author built custom JS widgets (color wheels for Color Filter and Color Balance, a draggable center for the vignette, that histogram) that mirror the underlying numeric values in both directions. So you get the ergonomics of a mini image editor without leaving the graph.

How it works

Like the rest of the pack, everything is pure tensor math - no models, no downloads. The core inputs every effect shares are effect, source, radius, and blend_mode. The pattern is: apply the effect to the channels chosen by source (same RGB/HSV/Oklab channel menu as the pack's Channel Ops node), then optionally blend the result over the original using blend_mode and a mask to restrict the effect to a region.

The effects worth singling out, because they're better than the usual custom-node fare:

• Halftone - 12 shape patterns (Dot, Line, Cross Cut, Random Dots…), Bayer-dithered, with size, angle (plus an angle wheel widget), contrast, brightness, and an inverse toggle. This is the one people search for a dedicated pack to get; it's here.
• Unsharp Masking - the classic amount / radius / threshold triplet, where amount is a multiplier and the radius is Gaussian. The threshold input is the key to avoiding halo artifacts: it stops the effect from firing on low-contrast areas.
• Levels - per-channel (levels_channel RGB/R/G/B) in/out black/white plus gamma, with the histogram widget. That's a real photo-editing control, not a toy.
• Color Balance - three-way shadows/midtones/highlights color wheels. Hue picks the tint direction, how far you drag sets the intensity.

The inputs that matter

You'll set effect and blend_mode (always visible), and the node shows the relevant widgets for your chosen effect automatically. radius is the shared spatial control (blur radius, etc.). The effect-specific widgets - halftone_shape, posterize_levels, vignette_amount, levels_in_black, cb_highlight_red, and friends - are all optional and hidden unless the matching effect is active. mask restricts the effect to a region and is auto-resized to your image.

Output is a single image, straight into Save Image or back into the graph.

Installing

Part of the ComfyUI Channel Ops pack:

• ComfyUI Manager → Install Custom Nodes → search "ComfyUI Channel Ops" → install → restart.
• Or manually: cd ComfyUI/custom_nodes && git clone https://github.com/L33chKing/ComfyUI_Channel_Ops, then restart.

No extra dependencies (torch/NumPy/PIL - already in ComfyUI), no model files, MIT licensed. Runs fine on CPU.

Gotchas

• The widget-hiding UI means a node can look near-empty on some effects and packed on others - that's intentional, not a bug. If you load an old workflow and see fewer widgets than expected, it's the adaptive UI hiding controls for the currently selected effect.
• sharpen_amount goes negative - negative values soften instead of sharpening. That's a feature (one slider for both directions) that reads as a bug until you know.
• Posterize's real dither modes (dither_mode: Bayer / Random / Floyd-Steinberg / Atkinson) are a nice touch that most post-processing nodes skip - worth using on big flat areas to avoid banding.
• Because this is the newest and least-searched node in the pack, its widget set changes between releases faster than the others. If a workflow you downloaded complains about a missing widget, update the pack and re-load.