I. Introduction
Recently, there has been a new trend in computer vision to use machines to express the "creativity" of art. Novel and never-seen-before images can be generated by inverting the convolution process in CNN ("upconvolution" or "deconvolution"), which gives such networks the ability to "dream" [23] and to generate images. To implement these tasks, deep generative models have been usually adopted, and these networks have also been employed for face-to-sketch translation. These deep models can be roughly divided into two categories, namely, the Generative Adversarial Networks (GANs) [4] and Variational AutoEncoders (VAEs) [11], [14], [18]. In GANs, there are two subnetworks, a generator and a discriminator, which play the two-player minimax game with a value function [4]. The generator acts as a mapping function to convert an input image to the generated image so that it fools the discriminator, which is trained to distinguish the generated images from the input real images. In this work, we rely on GANs as the basis to implement the face-to-sketch translation model.