Writing and reading .tif metadata

Beginner Questions
1

I am reading an image with imread:

out_image = itk.imread(files[0], itk.UC)

then changing adding metadata tags:

out_image['TileWidth'] = str(int(size[0]))
out_image['Date_start'] = other_image['Date']

When I run print(dict[image]), I see all the metadata. However, when I write out the image and read it in again and the metadata is not stored with the image.

itk.imwrite(out_image, str(out_file))
new_im = itk.imread(str(out_file), itk.UC)
print(dict(new_im))

What am I doing wrong please?

2

If you put the image through any processing, that typically removes the metadata. What file format are you writing?

3

I add the metadata in just before writing. I am writing to a .tif file.