Generative Adversarial Networks (GANs) have shown impressive results in modeling distributions over complicated manifolds such as those of natural images. However, GANs often suffer from mode collapse, which means they are prone to characterize only a single or a few modes of the data distribution. In order to address this problem, we propose a novel framework called LDMGAN. We ﬁrst introduce Latent Distribution Matching (LDM) constraint which regularizes the generator by aligning distribution of generated samples with that of real samples in latent space. To make use of such latent space, we propose a regularized AutoEncoder (AE) that maps the data distribution to prior distribution in encoded space. Extensive experiments on synthetic data and real world datasets show that our proposed framework signiﬁcantly improves GAN’s stability and diversity. Generative models (Smolensky, 1986; Salakhutdinov & Hinton, 2009; Hinton & Salakhutdinov, 2006; Hinton, 2007; Kingma & Welling, 2013; Rezende et al., 2014; Goodfellow et al., 2014) provide powerful tools for unsupervised learning of probability distributions over difficult manifolds such as those of natural images. Among these models, instead of requiring explicit parametric specification of the model distribution and a likelihood function, Generative Adversarial Networks (GAN) (Goodfellow et al., 2014) only have a generating procedure. They generate samples that are sharp and compelling, which have gained great successes on image generation tasks (Denton et al., 2015; Radford et al., 2015; Karras et al., 2017; Zhang et al., 2018) recently. GANs are composed of two types of deep neural networks that compete with each other: a generator and a discriminator. The generator tries to map noise sampled from simple prior distribution which is usually a multivariate gaussian to data space with the aim of fooling the discriminator, while the discriminator learns to determine whether a sample comes from the real dataset or generated samples. In practice, however, GANs are fragile and in general notoriously hard to train. On the one hand, they are sensitive to architectures and hyper-parameters (Goodfellow et al., 2014) . For example, the imbalance between discriminator and generator capacities often leads to convergence issues. On the other hand, there is a common failure issue in GANs called mode collapse. The generator tends to produce only a single sample or a few very similar samples in that case, which means GANs put large volumes of probability mass onto a few modes. We conjecture the mode missing issue in GANs is probably because GANs lack a regularization term that can lead the generator to produce diverse samples. To remedy this problem, in this work, we first propose a regularization constraint called Latent Distribution Matching. It suppresses the mode collapse issue in GANs by aligning the distributions between true data and generated data in encoded space. To obtain such encoded space, we introduce a regularized autoencoder which maps data distribution to a simple prior distribution, eg. , a gaussian. As shown in Figure 1 , we collapse the decoder of the regularized AE and generator of GAN into one and propose LDMGAN. Our framework can stabilize GAN's training and reduce mode collapse issue in GANs. Compared to other AE-based methods on 2D synthetic, MNIST, Stacked-MNIST, CIFAR-10 and CelebA datasets, our method obtains better stability, diversity and competitive standard scores.
We propose an AE-based GAN that alleviates mode collapse in GANs.
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