High-frequency noise is generated that approximates the appearance of traditional “film grain” for a digital video signal. By adding a relatively small amount of film grain noise, the video can be made to look more natural and more pleasing to the human viewer. The digital film grain generator can generate film grain in real-time. The generated film grain is preferably free from spatial or temporal patterns. Level adaptivity adjusts the amount of variation permitted for each pixel within a programmable range.