Docker image save how to check if exist before load?

Question

This way I can make a backup of an existing docker image to a safe place:

docker save  -o  /backitup/myimage.tar   myimage:v1

Then I can restore the image to another host or on the same with:

cat  /backitup/myimage.tar  | docker import --message "New image imported from tarball" - myimage:v1

But how will I know if the same image is already on the host maybe with a different name?

REPOSITORY           TAG                 IMAGE ID       CREATED              SIZE
myimage             v1                  1b6ef4d470ef   3 seconds ago        577MB
stillmyimage        dupe                a9a1468fdebf   4 minutes ago        577MB

Answer 1

This command replace the import and does exactly the job, load with name and don't create new if exist:

docker load < /backitup/myimage.tar

Loaded image: myimage:v1