Glossary
Bidirectional reflectance distribution function
“The bidirectional reflectance distribution function (BRDF) is a function of four real variables that defines how light is reflected at an opaque surface. It is employed in the optics of real-world light, in computer graphics algorithms, and in computer vision algorithms.”
A BRDF model is a 7 dimensional model containing geometry, textures and reflectance of the subject.
The seven dimensions of the BRDF are as follows:
- 3 cartesian X,Y,Z
- 2 for the entry angle
- 2 for the exit angle of the light.
Covert modeling
Covert modeling refers to both covertly modeling aspects of a subject i.e. without express consent.
Main known cases are
- Covertly modeling the human appearance into 7-dimensional [[#Bidirectional reflectance distribution function|]] model or other type of model.
- Covertly modeling the human voice
There is work ongoing to model e.g. human's style of writing, but this is probably not as drastic a threat as the covert modeling of appearance and of voice.
Deepfake
“Deepfake (a portmanteau of "deep learning" and "fake") is a technique for human image synthesis based on artificial intelligence. It is used to combine and superimpose existing images and videos onto source images or videos using a machine learning technique called a "generative adversarial network" (GAN).”
Light stage
“A light stage or light cage is equipment used for shape, texture, reflectance and motion capture often with structured light and a multi-camera setup.”