Glossary: Difference between revisions

From Stop Synthetic Filth! wiki
Jump to navigation Jump to search
(Sourced definition of w:deepfake to a {{Q}})
m (tweaks)
Line 1: Line 1:
= Ban Covert Modeling! wiki glossary =
== Bidirectional reflectance distribution function ==
== Bidirectional reflectance distribution function ==
[[File:BRDF_Diagram.svg|thumb|right|300px|Diagram showing vectors used to define the [[w:BRDF|BRDF]].]]
[[File:BRDF_Diagram.svg|thumb|right|300px|Diagram showing vectors used to define the [[w:BRDF|BRDF]].]]
{{Q|The '''bidirectional reflectance distribution function''' ('''BRDF''') is a function of four real variables that defines how light is reflected at an [[w:Opacity (optics)|opaque]] surface. It is employed in the [[w:optics|optics]] of real-world light, in [[w:computer graphics|computer graphics]] algorithms, and in [[w:computer vision|computer vision]] algorithms.|Wikipedia|[[w:bidirectional reflectance distribution function|BRDF]]}}
{{Q|The '''bidirectional reflectance distribution function''' ('''BRDF''') is a function of four real variables that defines how light is reflected at an [[w:Opacity (optics)|opaque]] surface. It is employed in the [[w:optics|optics]] of real-world light, in [[w:computer graphics|computer graphics]] algorithms, and in [[w:computer vision|computer vision]] algorithms.|Wikipedia|[[w:bidirectional reflectance distribution function|BRDF]]}}


A BRDF model is a 7 dimensional model containing geometry, textures and reflectance of the subject.  
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:  
The seven dimensions of the BRDF model are as follows:  
* 3 cartesian X,Y,Z  
* 3 cartesian X,Y,Z  
* 2 for the entry angle
* 2 for the entry angle
Line 16: Line 20:


Main known cases are
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 appearance''' into 7-dimensional [[#Bidirectional reflectance distribution function|]] model or other type of model.
* Covertly modeling the human voice
* 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.
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 ==

Revision as of 12:09, 3 April 2019

Ban Covert Modeling! wiki glossary

Bidirectional reflectance distribution function

Diagram showing vectors used to define the BRDF.

“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.”

~ Wikipedia on BRDF


A BRDF model is a 7 dimensional model containing geometry, textures and reflectance of the subject.

The seven dimensions of the BRDF model 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).”

~ Wikipedia on Deepfakes



Light stage

The ESPER LightCage - 3D face scanning rig is a modern 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.”

~ Wikipedia on light stages