👺➜▢ Convert mask to rectangle (with Blur)

Same job as the pack's plain Convert Mask to Rectangle node - collapse an irregular mask down into a solid rectangle - but with feathered edges instead of a hard cut. This one's also newer than the README's coverage, so there's no author write-up to quote; everything below comes from what the node's own parameters tell you.

Why the blur version exists

A hard-edged rectangular mask works fine if you're just cropping. But if you're compositing that region back into the original image - after an inpaint pass, a detail fix, an edit-model touch-up - a sharp rectangular seam is exactly the kind of visible artifact that gives away the edit. Feathering the mask's edges before compositing lets the paste blend rather than stamp. This node does the bounding-rectangle step and the feathering in one pass, so you're not chaining a separate blur node afterward.

The inputs that matter

It carries the same four positional offsets as its non-blur sibling - up, down, left, right (integers, -10000 to 10000, default 0) - to grow or shrink the rectangle before anything gets softened. On top of those, four more controls handle the feathering itself: blur_up, blur_down, blur_left, blur_right (floats, 0–100, step 0.1, default 0) set how far the soft edge extends inward from each side independently - useful if you want more feather on, say, the bottom edge blending into hair than on a hard-edged crop boundary elsewhere. tapered_corners (boolean, default true) rounds the corners of that blurred growth rather than leaving them square - the same option, and the same name, as ComfyUI's own built-in Grow Mask node, so if you've used that core node before this one will feel immediately familiar.

Output is a single MASK, ready for a composite step.

Installing it

Through ComfyUI Manager: search Bjornulf_custom_nodes, install, restart. Or by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/justUmen/Bjornulf_custom_nodes

Install the shared requirements.txt afterward. Like its non-blur sibling, this is pure mask math - none of the pack's video, TTS, or API dependencies are needed to make it run.

Where people get burned

Push the blur values too high relative to your rectangle size and you can feather the mask into near-nothing - a heavily blurred small region ends up with barely any solid center left to actually apply full-strength changes to. Start small (single digits) and increase only if you can still see a visible seam. And the same multi-blob caveat as the plain rectangle node applies here too: this collapses whatever you feed it into one rectangle, so a mask with two separate detected regions in it will get bridged into a single box spanning both - split multi-region masks before this node, not after.