Hi John,
I think that these questions might be best asked on the AI mailing list, so
I'm copying this thread to that list. I would suggest that further
discussion should take place on the AI mailing list, because that's where
the WMF experts on AI subjects are likely to participate.
Thanks for your interest in these questions. I too would be interested in
automating image categorization for Commons. I think that full automation
of image categorization would be a long term project, perhaps over the
course of decades, but there may be ways to make incremental progress. :)
Pine <https://meta.wikimedia.org/wiki/User:Pine>
<https://en.wikipedia.org/wiki/User:CatherineMunro/Bright_Places>
On Wed, Jan 24, 2018 at 1:20 PM, John Erling Blad <jeblad(a)gmail.com> wrote:
I had a plan to do a more thorough description on
meta, but my plans are
always to optimistic… ;)
Question 1: I wonder if anyone has done any work on categorization of
images on Commons by using neural nets.
Question 2: I wonder if anyone has used Siamese networks to do more general
categorization of images.
A Siamese network is a kind of network used for face recognition. It is
called Siamese network because it is two parallel networks in its simplest
form, but one of the networks are precomputed so in effect you only
evaluates one of the networks. Usually you have one face provided by a
camera and run through one network, and a number of other precomputed faces
for the other network. When the difference is small, then you have a face
match.
In general you can have any kind of image as long as you can train a kind
of fingerprint type of vector. This fingerprint will then acts like
locality-sensitive hashing [1]. Because you can create this LSH from the
vector, you can store alternate models in database, so you can later search
it and find usable models. Those models can then interpret the vector form
of the fingerprint, and by evaluating those models with actual input (ie
the fingerprint vector) you can get an estimate for how probable it is that
the image belong to a specific category.
What you would get from the previous process is a list of probable
categorizations. That list can be sorted, and a user trying to categorize
an image can then chose to select some of the categories.
Note that the output of the network is not just a few categories, it can be
a variant number of models that outputs a probability for a specific
category. It is a bit like a map-reduce, where the you find (filter) the
possible models and then evaluate (map) those models with the fingerprint
vector.
It is perhaps not obvious, but the idea behind Siamese networks are two
parallel networks, but the implementation is with a single active network.
Also the implemented network has a first part that computes the fingerprint
vector (kind of a bottleneck network) and the second part are the stored
models that takes this fingerprint vector and calculates a single output
for the probability of a single category.
[1]
https://en.wikipedia.org/wiki/Locality-sensitive_hashing
On Mon, Jan 22, 2018 at 6:47 AM, Pine W <wiki.pine(a)gmail.com> wrote:
Hi John,
I am having a little trouble with understanding your email from January
15th. Could you perhaps state your question or point in a different way?
Pine <https://meta.wikimedia.org/wiki/User:Pine>
<https://en.wikipedia.org/wiki/User:CatherineMunro/Bright_Places>
On Mon, Jan 15, 2018 at 5:55 AM, John Erling Blad <jeblad(a)gmail.com>
wrote:
> This is the same as the entry on the wishlist for 2016, but describes
the
> actual method.
>
https://meta.wikimedia.org/wiki/2016_Community_Wishlist_
> Survey/Categories/Commons#Use_computer_vision_to_propose_categories
>
> Both contrastive and triplet loss can be used while learning, but
neither
are
described at Wikipedia.
On Sun, Jan 14, 2018 at 8:16 PM, Pine W <wiki.pine(a)gmail.com> wrote:
Hi John,
I have not heard of an initiative to use Siamese neural networks for
image
classifications on on Commons. You might make a
suggestion on the AI,
Research, and/or Commons mailing lists regarding this idea. You might
also
make a suggestion in IdeaLab
<https://meta.wikimedia.org/wiki/Grants:IdeaLab>.
Pine <https://meta.wikimedia.org/wiki/User:Pine>
<https://en.wikipedia.org/wiki/User:CatherineMunro/Bright_Places>
On Sun, Jan 14, 2018 at 3:46 AM, John Erling Blad <jeblad(a)gmail.com>
wrote:
> Has anyone tried to use a Siamese neural network for image
classification
> > at Commons? I don't know if it will be good enough to run in
autonomous
> > mode, but it will probably be a huge
help for those that do manual
> > classification.
> >
> > Imagine a network providing a list of possible categories, and the
user
> just
ticks off usable categories.
>
> A Siamese network can be learned by using a triplet loss function,
where
> > the anchor and the positive candidate comes from the same category,
and
> the
> > negative candidate comes from an other category but are otherwise
close
> > to
> > > the anchor.
> > >
> > > Output from the network is like a fingerprint, and those
fingerprints
> can
> > > be compared to other images with known fingerprints, or against a
> > > generalized fingerprint for a category.
> > >
> > > John Erling Blad