Tolstikhin et al. proposed a Wasserstein Autoencoder (WAE), which minimizes a penalized form of
the Wasserstein distance between the model distribution and the generative distribution [
7
]. WAE
shares many of the properties of VAEs such as stable training, encoder-decoder architecture, nice
latent manifold structure while generating samples of better quality, as measured by the FID score.
A generative adversarial network (GAN) is a class of machine learning frameworks designed by
Goodfellow et al. in 2014 [
2
]. In GAN, the generative model learns to map from a latent space to a
data distribution of interest, while the discriminative model distinguishes candidates produced by the
generator from the true data distribution. The generative network’s training objective is to increase
the error rate of the discriminative network. Generative adversarial networks have applications in
many fields such as fashion, art and advertising, science, video games, and audio synthesis. There is
a veritable zoo of GAN variants. Conditional GANs [
2
] are similar to standard GANs except they
allow the model to conditionally generate samples based on additional information. For example,
if we want to generate a cat face given a dog picture, we could use a conditional GAN. The GAN
game is a general framework and can be run with any reasonable parametrization of the generator
G
and discriminator
D
. In the original paper, the authors demonstrated it using multilayer perceptron
networks and convolutional neural networks. Many alternative architectures have been tried such as
Deep convolutional GAN [6], Self-attention GAN [1], Flow-GAN [3].
1.2 Motivations
There were some new variants of GAN which allow the use of multiple data distributions and the
generated ones such as the conditional GAN. However, these new variants of GAN require least
two different training sets to generate a new one. In many applications in practice, we would like
to generate a new dataset which have the same characteristic as a reference one. In this work, we
aim to develop a new variant of GAN which allows to perform this task. Our work is motivated by
applications in generating new kinds of rices which have similar characteristics as a good rice.
More specifically, assume that we have
L
datasets with unknown distribution
p1, p2,··· , pL
for
some
L≥1
. We aim to generate a new dataset which has a different distribution from the training
datasets. In addition, the Jensen-Shannon divergence between the distribution of the generative
dataset and a mixture data distribution can be controlled, i.e.
JSD(PL
l=1 αlpl,pg)≤δ
for some
given non-negative tuple
(α1, α2,··· , αL)
satisfying
PL
i=1 αi= 1
and
δ∈[0,1]
. For
L= 1
, our
algorithm generates a new dataset such that the Jensen-Shannon divergence between the distributions
of the generative and the training data is upper bounded by some target δ∈[0,1].
This additional “controllable property" is very important in many applications. For example, we
sometimes need to generate a new cat gender (images) which owns most properties as an old gender of
cats. In many other applications, we may increase the number of new generated images by lessening
the distance requirement between the distributions of data and generated ones compared with GAN
or conditional GANs.
1.3 Contributions
Our main contributions include:
•
We develop a new technique which allows to control the total variation between the distribu-
tion of the random vectors
x
and
y
where
y=x+z
and
z
is a sparse random vector with
fixed distribution.
•
We propose a mechanism to which allows to loosen Jensen-Shannon divergence between
the distribution of the generated distribution and the data distribution in the Goodfellow et
al’s model [2].
•
We extend this new model to allows the use of multiple data distributions as in the conditional
GAN.
•
We illustrate our ideas on datasets Cfar10 and Cfar100, and generate new datasets based on
only one dataset or a mixture of these two datasets for different values of δ.
2