Fix a moving subject in four steps
- Open the photo. A child running, a dog turning, a hand waving — something moved while the rest stayed still.
- Paint the subject. Brush over the part that moved. Erase mistakes. The painted area is tinted.
- Measure the subject. Kernel B is measured on the painted area itself. Adjust it on its dial if needed; keep or switch off kernel A for the background.
- Save at full size. Both passes run at full size and are joined along the feathered edge. The receipt lists both kernels.
Why one kernel is not enough
A single kernel assumes the whole frame smeared the same way. When the camera was steady and the subject moved, the background is sharp and the subject is streaked — and one kernel either leaves the subject blurred or rings the background. Two kernels, one per region, fix each part for the movement it actually had.
| Subject moved, camera still | Kernel B on the subject; background off. |
|---|---|
| Both moved, differently | Kernel B on the subject, kernel A on the rest. |
| Only the camera shook | One kernel is enough — use the motion deblur. |
| Subject too fast | Beyond reach; the page will not pretend. |
When this will not help
- Subjects that moved further than this method reaches (about a twentieth of the frame).
- Movement that was not a straight line — a spinning wheel, a waving arm in an arc.
- Faces that moved many pixels: features are gone, and nothing here invents them.
The whole frame shook? Use motion deblur. For a kernel of any shape, try deblur with your own kernel.
Questions
How is the subject's kernel measured?
From the painted area alone: the smallest box around what you painted, with a margin, is measured with the same method the whole frame uses — the direction the edges smeared in and how far. You can adjust the result on its dial.
Can the background be left alone?
Yes. Switch kernel A off and everything outside the painted area stays exactly as it arrived; only the subject is treated.
Will there be a visible seam?
The painted region has a soft, feathered edge, and the two results are blended across it. Both passes keep the artifact guard on, so neither side rings into the other.
Is this a face restorer?
No. It undoes a measured smear on whatever you paint. Where a face moved more than a few pixels, the detail is gone and is not generated.
When won't this work?
When the subject's movement was long or curved, when the subject is very small in the frame, or when the painted area holds too few edges to measure — then set kernel B by hand.
Is my photo uploaded?
No. Painting, measuring and both passes run in this browser tab.
Related
- Motion deblurOpen straight into the motion kernel, and read the dial before trusting what it rebuilds.
- Deblur with your own kernelPaint, estimate or import a 2D kernel and deconvolve with it.
- Unblur a faceFaces found on this device and refined gently; no face is generated.
- Unblur an imageDiagnose the blur, then reconstruct it, with the kernel on a dial.
