ausboss-ComfyUI-AusBoss/js/docs/AUSBOSS_NODES_RealignToSource.md

Realign to Source (EXPERIMENTAL)

Lines an edited picture back up with the original.

Qwen Image 2.1 often draws an edit slightly zoomed in or shifted, especially style changes like watercolor or anime. Lay the edit over the original and it no longer matches: the horizon sits lower, a face is a little bigger. This node measures how far the edit moved and moves it back.

Quick start

1. Wire the edit into edited and the original picture into source.
2. For the best result, add a margin before editing: pad the picture with Load Image + Pad 🆎 (mirror fill, 64 px a side), edit the padded picture, and plug its stitcher in here. The edit then has room to move, and you get your picture back with real picture all the way to the edges.
3. Wire report into Show Text 🆎 to see what it found.

Using the Qwen Image 2.1 consistency LoRA? Skip the margin: the LoRA already keeps the edit in place, and this node trims what's left.

Experimental: tested on Qwen Image 2.1 edits. The settings keep their names from here on; how it measures may still improve.

What it fixes, and what it doesn't

• Fixes: the whole picture drawn zoomed in or shifted. Horizons, posts and faces land back where they were.
• Doesn't fix: things the edit redrew in a new spot. A watercolor that moved a boat keeps the boat where it drew it, so the result lines up closely, not pixel for pixel.
• Leaves alone: a picture it can't measure, or a zoom bigger than Max zoom. That picture only comes out resized, and the report says why.

Controls

• edited: the edited picture.
• source: the original picture you edited, at the size the edit model saw it (in the Qwen Image 2.1 Edit + Realign example, the Image Resize output). The result comes out at this size. For a batch or a video, give one source picture, or one per edited frame.
• stitcher (optional): from Load Image + Pad 🆎 when you padded the picture before editing. Image Crop + Rotate + Pad 🆎 works too. A Crop For Inpaint 🆎 stitcher does not work here.
• Fit: zoom + shift (the default) fixes the usual Qwen drift. affine also fixes a slight tilt.
• Empty fill: when the edit slid past the edge, a thin strip ends up with nothing in it. edge (the default) stretches the nearest pixels into it, source fills it from the original, gray fills it flat gray for inpainting. With a big enough margin there is no strip.
• Max zoom: the biggest zoom it will undo, in percent (20 by default). Anything bigger is treated as a change you meant and left alone.

Outputs

• image: the edit, lined up with the original and at its size.
• empty_mask: white where the lined-up edit has nothing (a strip that slid off the edge), black everywhere else. Crop the strip off or inpaint it.
• report: one line on what it found, for example realigned: zoom x -0.25%, y +5.24%; shift x +1.0, y +30.1 px; worst corner 61.1 px (142 of 162 areas agree, fit error 3.2 px); warped once; empty strip 5.0% of the frame; to keep real picture there, pad the source before editing: bottom 77 px
  • zoom and shift: how much bigger the edit was drawn, and how far it had moved.
  • worst corner: how far the corner that moved most had moved, in pixels.
  • cut out whole, no resampling: the edit only needed sliding back, so its pixels are untouched. warped once: it also needed resizing, done in one step.
  • empty strip: how much of the picture ended up with nothing in it. When it names a side and pixels, pad that side by that much next time. With a stitcher wired in, it says "the margin was too small" and how much to add.
  • A picture it left alone reads left as is: and the reason.
  • A batch or a video gets one line per frame, each starting frame N:.

Why it happens

Qwen Image 2.1 redraws a broad edit with slightly different proportions. Watercolor, anime and oil edits come back about 4% taller on average and up to 12%: 30-40 px at the edges of a 1 MP picture, up to 90. It changes with the seed and the prompt, and snapping sizes to 32, 64 or 112 does not help. Light edits (a colour change, "keep it the same") hold within 0.4%. Keep the sampler on the Qwen encoder's own latent output too: a canvas of another size makes the model shrink the whole picture to fit, which is a separate zoom this node is not meant to undo.

Tips

• Feed source the same picture the edit model saw (or plug in its stitcher), and keep the sampler on the Qwen encoder's own latent output.
• With the consistency LoRA: no margin needed.
• Without it: pad 64 px a side with Load Image + Pad's mirror fill and plug in the stitcher. Mirror padding looks like more of the scene; flat gray or stretched edge pixels look like a border, and the model is more likely to zoom in to fill it. A 64 px margin costs about 27% more render time at 1 MP.
• Every seed drifts differently. If the empty strip is too wide, another seed often drifts less.
• On light edits (a colour change, a small fix), a zoom under 0.5% in the report means the model held still.

Technical details

The rest of this page is for people who want to know how it works and how it was tested.

How it measures

Both pictures become edge maps (gradient strength, normalised by its surroundings), so a restyle, a relight or inverted tones still line up. Blocks are compared by band-limited phase correlation: first at 256 px on the long side to find the drift, then twice at 768 px after warping the edit by the estimate, so the blocks are compared at the same scale. The first pass also tries the edit at a few zooms (0.86x to 1.28x) when it doesn't line up as it is, so a large zoom such as a reframe is found too. A robust fit turns the block shifts into the zoom and shift; blocks that disagree with it by more than a few pixels (8 at most), such as a redrawn boat or a new cloud, are left out. It trusts the fit when at least 10 blocks, and at least a quarter of them, agree. With a stitcher, the blocks tile the picture's area only.

It runs on the CPU in a fraction of a second per 1 MP frame. No new dependencies, and no model.

Measured

• Planted drifts (zoom up to 12% per axis, shifts, a slight rotation with affine, restyled copies, edits at another resolution; with a margin, a reframe of 27-33% that nearly fills the canvas): recovered within about 0.1 px at the corners, 0.2 px on the reframe. Without the coarse pass's zoom tries, a 30% zoom was lost (137 px off); with them it is found.

• 166 real Qwen Image 2.1 edits of four pictures: 164 measured. The two it left alone were sampled on a 1024x1024 canvas for an 832x1216 picture (the wrong-canvas squeeze), and the report names that. Re-measured by a separate estimator after realigning, the worst corner of the 94 style edits went from 35.5 px to 4.6 px (median); light edits from 2.1 px to 0.1 px.

• Margins, 16 held-out edits (12 restyles, 4 light edits; each at one seed with a 64 px margin, realigned, then re-measured against the source):

  setup	worst corner before (median)	after (median / worst)	frames with an empty strip
  no margin	40.0 px	0.10 / 5.8 px	13 of 16
  mirror margin	24.0 px	0.42 / 5.6 px	1 of 16
  edge-pixel margin	61.2 px	0.52 / 5.5 px	6 of 16
  gray margin	43.1 px	0.81 / 9.1 px	5 of 16
  consistency LoRA, no margin	1.5 px	0.06 / 0.4 px	10 of 16 (0.2% median, 2.7% worst)
  consistency LoRA + mirror margin	1.8 px	0.31 / 3.4 px	0 of 16

  Mirror padding made the model zoom in more than 8% to fill the canvas on 2 of 16 edits, against 7 with edge pixels and 5 with gray (it once painted the gray as a watercolor's paper margin). With the LoRA, a margin still tempted one edit into zooming, and the unpadded LoRA path is the most precise, which is why the Tips say no margin with the LoRA.