What is comfyui-contextanchoredtilerefine?

Context-Anchored Tile Refine is a custom node for ComfyUI, a visual interface for building image generation workflows. It solves a specific problem: when you enlarge an image and then try to improve its quality, the improvement process often needs to work on small pieces (tiles) because the full image is too large for the model to handle at once. Stitching those tiles back together usually leaves visible seams. This node processes each tile while looking at the already-finished tiles next to it, so the pieces blend together without visible boundaries. The node takes an already-upscaled image and breaks it into tiles based on maximum width and height settings you provide. Each tile is processed in raster order, meaning left to right, top to bottom. By the time any given tile is processed, its top and left neighbors are already refined. The node gives each tile a frozen border of that finished content to condition against, which keeps tiles consistent with each other rather than drifting apart in style or color. There is also a context overlap setting that controls how wide the shared band between neighboring tiles is. A wider band helps with smooth areas like sky, while detailed scenes need less. The way seams are hidden is built into the node and cannot be adjusted. The node cross-dissolves the overlapping band between two tiles, and the midpoint of that dissolve bends around image content rather than running in a straight line. It does this using a technique from a 2001 SIGGRAPH paper on image quilting, which finds the path through the overlap where the two tiles already agree most closely. A straight boundary is easy to spot even when faint, but one that follows the detail in the image is not. The node also supports masked refinement, where you can select a specific region of an image to improve while leaving everything else untouched. The node crops to the masked area plus a border of surrounding context, refines only that region, and composites it back with a one-pixel anti-aliased edge. You can run a second pass with an inverted mask to refine other areas with different settings. There are some limitations. The guider input lets you use options like Perp-Neg Guider, but the conditioning covers the whole image rather than being recalculated per tile, which means ControlNet is not supported. The project is released under the GPLv3 license.