What is it called when multiple photos are adjusted for further blending?

Question

I have taken a series of noisy photos without a tripod.

I want one less noisy version, so I need average them down to one photo.

But details of the individual images do not exactly match, so that naive attempt will lead to a blurred/ghosted image, so I need to move/rotate[/scale/whatever] all images to match the first and then average them?

What is this technique called?

1. Adjusting
2. Stabilisation
3. Synchronising
4. Converging
5. Deshaking
6. some other term?

@related http://superuser.com/questions/256787/how-to-adjust-and-combine-multiple-lower-quality-photos-into-one-better-using-fos

Asked by Vi0

Answer

The answer you are looking for is Image Aligning.

When you merge images for HDR on Photoshop, there is an optional 'Automatically Align Images'. The same option exist in several cameras with built-in HDR capabilities.

It is also sometimes called Image Registration but that term is overloaded as it has other meanings, for example relative to copyright.

Stacking, HDR Merging, Exposure Blending are what you do with images that are aligned already.

Answered by Itai

Check more discussion of this question.