This paper presents a novel method for labeling real-world neuromorphic camera sensor data by calculating the likelihood of generating an event at each pixel within a short time window, which we refer to as" event probability mask" or EPM. Its applications include (i) objective benchmarking of event denoising performance,(ii) training convolutional neural networks for noise removal called" event denoising convolutional neural network"(EDnCNN), and (iii) estimating internal neuromorphic camera parameters. We provide the first dataset (DVSNOISE20) of real-world labeled neuromorphic camera events for noise removal.