ImageFilterSharpen

ImageFilterSharpen is about as minimal as a filter gets: one images input, no knobs, one sharpened batch out. It applies PIL's built-in SHARPEN kernel to every image in the batch and hands them back the same size, same count, same alpha channel. If you've ever wanted a "make it crisper" button, this is it.

The catch - and it's worth knowing before you reach for it - is that there's no strength slider. The node just applies the default sharpen kernel, full stop. PIL's SHARPEN is a fixed 3×3-style unsharp-ish kernel that boosts edge contrast; it's subtle and safe on most images, which is exactly why a no-parameter version works at all. For anything where you need control - mild retouch versus a hard detail pop - you'd normally want an unsharp-mask node with adjustable amount and radius. This node is the "good enough, always works" option.

Where it earns its place:

• Post-upscale crispening. Blow an image up and it gets soft; one pass of this after the upscaler is the cheapest fix there is.
• Batch-friendly. It processes every image in the batch, so a 30-frame animation strip gets the same treatment with no per-frame nodes. That multi-image handling is one of Allor's design pillars.
• Alpha-safe. A fourth channel survives intact, so you can sharpen an RGBA cutout without nuking the transparency.

Output is an IMAGE tensor wired straight into whatever comes next - a Save Image, a composite, or the next filter in a chain. Nothing else to configure, nothing to break.

Installing it

It's part of the Allor plugin:

cd ComfyUI/custom_nodes
git clone https://github.com/Nourepide/ComfyUI-Allor
cd ComfyUI-Allor
pip install -r requirements.txt

Restart ComfyUI, or install "Allor" from ComfyUI Manager. Pack-level notes: requirements.txt installs rembg and onnx for the segmentation nodes even though this filter only needs PIL (already in ComfyUI), and Allor's repo was rebased to strip images from git history - which can make auto-updates fail. The docs at nourepide.github.io/ComfyUI-Allor-Doc have troubleshooting pages for that.

Real talk

ImageFilterSharpen is the "one weird trick" node: it does one thing, does it without asking questions, and disappears into a bigger workflow. The trap is expecting it to fix a genuinely blurry image - it won't; a fixed-kernel sharpen can only do so much, and heavy blur needs a real restoration or at least a proper unsharp mask. For routine crisping of already-decent images, though, it's a single node that just works. Sometimes that's exactly what you want in the middle of a chain.