Slice, upscale and stitch an image in a workflow

Last updated: October 22, 2026

Cut a large image into overlapping tiles, process every tile, and put them back together as one image, with no visible seams.

Some models cap the size of the image they take or return. Slice Image and Stitch Tiles get around that in a workflow: Slice Image cuts the image into a grid of tiles, the nodes in between work on each tile at a size they handle well, and Stitch Tiles reassembles the results. The most common use is upscaling an image past what one upscale can do in a single pass.

Before you start

  • You need a workflow open on the canvas. See Build and publish a workflow.

  • Each tile a node in the middle processes is its own run, so a 4 by 4 grid costs sixteen runs of that node. See Creative Units for how runs are charged.

Steps

  1. Add Slice Image from the Utilities group and wire your image into its Images input.

  2. Set Columns and Rows, then open Advanced and set Overlap X and Overlap Y. Before the run, the node shows your image with the cut drawn over it: a line along each tile's edge, and the strips neighbouring tiles share shaded darker.

  3. Add the node that works on each tile, such as Upscale Image from the Editors group, and wire Slice Image's Images output into it. It runs once per tile.

  4. Add Stitch Tiles from the Utilities group and wire the processed tiles into its Tiles input. Leave Blend, under Advanced, on Feather unless you need hard edges (see below).

  5. Select Stitch Tiles and select Run. The nodes before it run first.

Result

Stitch Tiles outputs one image per image you sliced, as a PNG. Its size follows the tiles: when the tiles come back three times larger, the stitched image is three times the size of the original. It keeps transparency where the tiles have it.

How Slice Image cuts

Slice Image cuts each input image into a grid of Columns by Rows tiles and outputs them in reading order: left to right, then top to bottom. With several input images, it cuts each one and outputs their tiles one image after the other. Its other settings change where the cuts fall.

Overlap

Overlap X is how many pixels each tile shares with its left and right neighbours, and Overlap Y how many it shares with the tiles above and below. The grid still spans the whole image, so overlapping makes every tile larger rather than adding tiles. On a 1600 pixel wide image cut into 2 columns with an overlap of 128, each tile is 864 pixels wide and the two share the 128 pixels in the middle.

Overlap is what makes a seamless stitch possible. A model that works on one tile sees nothing of its neighbours, so where two tiles meet it can draw detail that does not line up. With an overlap, both tiles carry the same strip of the picture, and Stitch Tiles blends across it instead of placing two hard edges side by side.

Offset

Offset X and Offset Y shift the whole grid right or down (a positive value) or left or up (a negative one) by that many pixels. Use an offset to move a seam off a detail you want to keep whole, such as a face or a line of text.

A shifted grid no longer lines up with the image. On the side the grid moves away from, a strip of the image falls outside every tile; on the other side, the outer tiles reach past the image's edge. The preview shades a strip no tile takes heavily, so you can see it before you run.

Pad edges

Pad Edges decides what a tile that reaches past the image's edge holds. On, the part past the edge is filled with transparency, so every tile keeps the same size. Off, those tiles are cropped to the image and come out smaller. Keep it on when the node in the middle expects tiles of one size.

Inset and trim

Inset trims that many pixels off every side of each tile, to drop gutters or borders between the cells of a sprite sheet. Trim Transparent crops each tile to its opaque area. Both are for cutting a sheet into separate pieces; for a slice and stitch, leave Inset at 0 and Trim Transparent off, so the tiles cover the whole picture.

How a tile remembers where it came from

Every tile Slice Image cuts carries its place in the original image: which cut it belongs to, its position in that cut, how many tiles the cut has, the box it covers and the size of the original. You never wire this anywhere. A node that changes one image into another, such as Upscale Image, Remove Background or Edit Image given a single tile, passes the tile's place on to its result. Stitch Tiles reads it from each tile it receives.

That is why Stitch Tiles takes only the tiles. They can arrive in any order, and tiles from several sliced images can arrive in one list: Stitch Tiles sorts them by the image they were cut from and makes one image from each.

How Stitch Tiles blends

Stitch Tiles puts each tile back in the box it was cut from. Tiles that come back at another size are resized to fit, and the first tile of each cut sets the scale of the result. Where tiles overlap, Blend decides how they meet:

Feather

Each tile fades out across the strip it shares with its neighbour while the neighbour fades in, so the two cross-fade. This hides small differences between tiles and is the right choice for upscales, edits and painterly images.

Hard

The tiles meet in a straight cut at the middle of the overlap, with no blending. Use it for pixel art and flat graphics, where a cross-fade would soften crisp edges.

The tiles do not have to overlap. Without an overlap, Stitch Tiles places them edge to edge, which is fine when the node in the middle keeps each tile's edges where they were.

Production tips

  • Size the overlap to the model. An overlap of about an eighth to a quarter of a tile's width gives the blend room to hide differences. Upscalers that invent detail need more than ones that only sharpen.

  • Upscale in two passes. For a very large result, upscale the whole image once, then slice, upscale the tiles and stitch. The first pass sets the composition; the second adds detail the first could not fit.

  • Keep the tiles in step. Give the node in the middle the same settings, seed and reference set for every tile, so neighbouring tiles agree on colour and style. Keep its batch size at 1: every tile must come back exactly once.

  • Check the preview first. The Slice Image preview shows the cut on your image before you spend a run. Move seams off faces, eyes and text with an offset.

  • Pick tiles out with Select Images. To retouch one tile on its own branch, wire Slice Image into Select Images and pick it by its position in reading order.

If something goes wrong

  • Stitch Tiles says it received an image that was not cut by Slice Image. A node between them made a new image instead of changing the tile, so the tile's place was lost. That happens with nodes that take several images at once, or that generate from a prompt alone. Keep only nodes that change one image into one image between Slice Image and Stitch Tiles.

  • Stitch Tiles says it received some of the tiles of a cut, or a tile more than once. Every tile has to arrive exactly once. Check that no node in between drops tiles (Select Images) or makes several results from one (a batch size above 1).

  • The stitched image would be too large. Stitch Tiles refuses a result above its size limit. Upscale by a smaller factor, or slice a smaller part of the image.

  • Seams still show. Increase the overlap and use Feather. If the tiles differ in colour, the node in the middle is changing them too much; lower its creativity or similar setting.

Related