I'm really curious and I'd like to know how the "Noise"-effect in Premiere Pro technically works. I want to understand what happens mathematically to the footage to make it look noisy (as in film grain).
Does anyone know how this works and what parameters are being changed/applied in the software?
I'm not an engineer, but as I understand it, noise (and all image processing effects) gets made by manipulating mathematical expressions. With noise, it's usually on a "matrix" of values. In this case, they are likely numbers from a random number generator. By continuously feeding the matrix with these random numbers, the noise will also appear as random, so it looks like it is animated.
I found a white paper on image processing and noise if you are interested. Check out Page 3: Impulse Valued Noise (Salt and Pepper Noise). This kind of noise in the Premiere Pro effect looks like it is blended with the video using a blending mode.
I'm unsure how the effect is constructed for Premiere Pro in terms of its code, but I could find out if you want me to.