Bounded Image Blend with Mask

This node is the "put it back" half of a workflow whose "take it out" half you've probably already used without thinking about the name: crop a region out of a bigger image, generate or edit just that crop (cheaper, more detail, easier to control), then composite the result back into the original at the exact same location. WAS calls that region a "bounds," and it has a matched set of nodes for it - Image Bounds to define the box, Bounded Image Crop to cut it out, and Bounded Image Blend with Mask to stitch the edited crop back in.

The "with Mask" part is what separates it from the plain Bounded Image Blend node: instead of overwriting the bounded region wholesale, it uses a mask to control which pixels of the edit actually replace the original, so you get a feathered, mask-controlled composite rather than a hard rectangular paste. That's the same principle behind any decent inpaint-and-composite pipeline - a generous, blurred mask stops the result looking pasted on, a tight hard-edged one produces the visible seam everyone's trying to avoid.

How it works

Feed it the original full-size image, the edited crop, and a mask, and it blends the crop back into the original at the bounded location according to that mask - white areas take the new content, black areas keep the original, and anything in between blends proportionally if the mask is soft. The output is a single composited IMAGE at the original image's full size, ready to save or feed downstream - you're not working with the small crop anymore once this node runs.

What matters when you set it up

The three things you're actually supplying are the base image, the processed crop, and the mask that governs the blend - get the bounds consistent between the crop step and this blend step (same region in, same region out) or the composite will land in the wrong place. A mask with soft edges, not a hard binary one, is what gives you the seamless result the whole "bounded" family of nodes exists for.

How to install it

ComfyUI Manager: search "WAS Node Suite," install, restart. Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/WASasquatch/was-node-suite-comfyui

then, inside that folder, install requirements - path/to/ComfyUI/python_embeded/python.exe -s -m pip install -r requirements.txt on portable, pip install -r requirements.txt on system Python. Restart ComfyUI; the bounded-image nodes live under WAS Suite.

Common issues & troubleshooting

If the composite looks visibly pasted-on, that's a mask problem, not a node bug - the standard fix documented for inpaint compositing generally is "generous mask overlap... and adequate mask blur," and it applies here just as much as to any other paste-back step. Feed this node a hard-edged mask and you'll get a hard-edged seam no matter how good the crop's contents are; run it through Mask Dilate Region and Mask Gaussian Region first if your source mask is too tight or too crisp.

Beyond that, the failure mode to know about is the pack, not this node: WAS Node Suite has had no active development since it was marked retired in December 2023, and the recurring community complaint is the whole suite going "Import Failed" after a ComfyUI update - usually because the upgrade downgraded a shared dependency WAS still pins for older support. If that hits you, reinstall the requirements using your embedded Python interpreter specifically rather than a system one; that's the fix that's actually worked for people stuck on it.