Where are docker images stored locally ?

http://blog.thoward37.me/articles/where-are-docker-images-stored/

Local Storage on the Docker Host

So far I've been explaining the intricacies of remote storage, and how that relates to the confusing vocabulary, but running docker images shows you only what is local to your machine.
Where is this stuff? The first place to look is in /var/lib/docker/.

Open up the file repositories to find a JSON list of the repositories on your host:

$ sudo cat /var/lib/docker/repositories | python -mjson.tool
{
    "Repositories": {
        "ubuntu": {
            "12.04": "8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c",
            "12.10": "b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc",
            "latest": "8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c",
            "precise": "8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c",
            "quantal": "b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc"
        }
    }
}

Hey, that matches the output from docker images!

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              12.04               8dbd9e392a96        8 months ago        131.3 MB (virtual 131.3 MB)
ubuntu              latest              8dbd9e392a96        8 months ago        131.3 MB (virtual 131.3 MB)
ubuntu              precise             8dbd9e392a96        8 months ago        131.3 MB (virtual 131.3 MB)
ubuntu              12.10               b750fe79269d        8 months ago        24.65 kB (virtual 179.7 MB)
ubuntu              quantal             b750fe79269d        8 months ago        24.65 kB (virtual 179.7 MB)