Deleting TIF Image from DNG possible?

[Beholder3]

I come back to a thought I had before. It's about actually removing the main image information from a DNG file.
Is that doable somehow?

Is it possible to remove the embedded preview files?

In the end only the empty shell DNG file with meta should remain.

Other than deleting:
Would it be possible to replace the embedded main image by some other TIF image (e.g. a blank white one)? Would replacing be possible with the embedded jpg previews?

[Phil Harvey]

You should be able to replace or delete the preview images, but ExifTool can not be used to modify the main image.

The best you could do is to copy all metadata to a .EXIF file, which is basically a TIFF image without the image:

exiftool -o out.exif -all:all source.tif

But note there will be a number of unsafe and unwritable tags that won't be copied.  The unsafe tags may be specified individually to force them to be copied, but the only solution for the unwritable tags is with user-defined tags, which would be a lot of work if there are a large number of tags.

- Phil