Combine Tiles

Every tiled upscaler ends at the same wall: you cut the image apart, do your work, and now you have to glue it back together without leaving a visible grid of seams. Combine Tiles is the glue. It takes the processed tiles from Divide Image and Select Tile, lays them back down at their original coordinates, and blends the overlapping edges so the seams disappear.

The blending is where the quality lives. Each tile gets a mask that's fully opaque in the center and falls off through the overlap zone toward the edges - a Gaussian blur for overlaps wider than 64 pixels, and a box blur for narrower ones (the 2.0.3 changelog swapped that in after Gaussian started leaving artifacts on tight overlaps). Tiles on the outer edge of the image keep their outside edges sharp, so you don't get a soft halo around the whole result. The overlap pixels are effectively averaged through the blurred mask, which is what turns two adjacent-but-slightly-different tiles into one continuous image.

It's also the node that makes the whole "per-tile processing" idea safe. Because it takes dac_data from the Divide and Conquer Algorithm node, it knows the exact grid, tile size, and overlap the split used - it doesn't guess, and it doesn't care how each tile was processed in between. You can run every tile through a different prompt, a different denoise, even a different model, and the stitch-up still lands exactly right.

Inputs and outputs

• images - the tiles, as a list, from the ALL TILES output of Divide Image and Select Tile.
• dac_data - from the Divide and Conquer Algorithm node.
• IMAGE - the combined, upscaled result. Save it, preview it, feed it to the next stage.

That's the whole node. Two wires in, one image out.

Install and gotchas

Same pack, same install as everything else in the suite:

cd ComfyUI/custom_nodes
git clone https://github.com/Steudio/ComfyUI_Steudio

Restart, done. No dependencies, nothing to download.

The one real failure mode is seams - and the author's own tip is the fix: if seams appear, increase the overlap. That means going back to the algorithm node and raising min_overlap (1/32 tile is a stingy default; 1/8 to 1/4 is the realistic range), because overlap is baked into the plan in dac_data and flows through here automatically. Seams in a D&C combine are almost always an overlap-too-small problem, not a combine bug - the community's read on this pack is that it sews tiles together more reliably than Ultimate SD Upscale, provided you gave it enough cloth to work with.