generate a bytesio stream that makes zarr look like nii

[satra]

this is a potential feature request to make a bytestream based on a zarr backend look like nifti that can be passed on to nibabel. this approach if implemented could make it easier for people to save to zarr and read with existing tools. ideally such a wrapper would exist in several languages, but starting with python should address a large community who use nibabel.

[balbasty]

Hi Satra, that sounds good and should be pretty straightforward. Do you envision a preloaded bytes object (faster but forces the pyramid level of interest to be fully loaded in memory), or a BytesIO stream (might be slow as the bytes order is different in zarr and numpy -> it'll read a full chunk to only return a line).

Note that the zarr2nii function that is currently implemented already returns a nb.Nifti1Image, where the dataobj is a dask array.

[satra]

Note that the zarr2nii function that is currently implemented already returns a nb.Nifti1Image, where the dataobj is a dask array.

in that case this issue is less important. i don't think it can be preloaded for large files. btw, i'm surprised bytesorder is still a challenge across zarr and numpy. does it affect indexed access? or only pure byte sequence access?