I was reading an article and this sentence was unclear to me:
An encoder-based generative model is a function $G : z → x$ that generates an image $x \in R^{H \times W\times3}$ from a latent representation $z \in R^{h \times w\times |z|}$. What does $R^{H \times W\times3}$ mean? I know that $R$ mean real numbers.