Image metadata should be copied when creating a new layer

Hi,

🚀 Feature

Existing metadata of an image should be copied when creating a new non-image layer. E.g. if an image has a certain voxel spacing defined in the metadata dict with the attribute spacing than a newly created labels layer should have the same voxel spacing.

Motivation

Some image formats such as nifti (.nii.gz) have important metadata information such as spacing, affine transform or axis orientation. This information needs to be the same for all non-image layers that correspond to that image. Otherwise this can lead to problems with other software when exporting the new layers.

Pitch

A new non-image layer should copy the metadata dict of an already existing image layer.

Best, Karol

[jni]

Or is there some other way on how to achieve this with the current version of napari

Nothing seamless, but you can certainly make a plugin to do this, “copy metadata”

from magicgui import magic_factory
import napari

@magic_factory
def copy_meta(src: napari.layers.Layer, dst: napari.layers.Layer):
    for attr in ['scale', 'translate', 'rotation', 'skew', 'affine']:
        setattr(dst, attr, getattr(src, attr))

Then you can make a new layer, open the widget, and copy the attributes.

[tlambert03]

I kind of need this 🙂

Any interest in opening a PR? We can certainly help out if you run into difficulty. Otherwise yes it’s still on the todo list, but waiting for someone to have time.

Thanks for the bump!