3D Chroma Keyer

vfxwiki  >  Post Techniques  >  Matte Generation  >  Keying  >  Keyer Types  >  Chroma Key  >  3D Chroma Keyer
Page's that link from here:

Intro

Using 3d maths in non-rgb colour space to extract a matte

Simple 3d chroma keyer

This is a 3d Keyer used in HLS space based on 3d trigonometry.
Matte = square root [[R1-R2]^2+[G1-G2]^2+[B1-B2]^2]
As Shake layerX equation: sqrt((pow((r-r2),2))+(pow((g-g2),2))+(pow((b-b2),2)))

Sophisticated 3d chroma keyer

Modern chroma keyers such as Primatte or the 'Modular Keyer' use 3d representations of the colourspace to extract a matte using color space segmentation volume carving.


Primatte

"Primatte is a high-end chroma key technology used in motion picture, television and photographic host applications to remove solid colored backgrounds (greenscreen or bluescreen usually) and replace them with transparency to facilitate ‘background replacement’. It uses a unique algorithm based on three multi-faceted polyhedrons floating in RGB colorspace that are used to isolate color regions in the foreground image. Primatte is often referred to as a compositing technology and is usually used as a plug-in for host products such as Adobe After Effects, Adobe Photoshop, Autodesk Media and Entertainment Inferno or Flame, Eyeon Fusion and several other compositing and editing software packages." - From Wikipedia, the free encyclopedia - March 2008(external link) (cache)

External Links

External Links

http://en.wikipedia.org/wiki/Chroma_key(external link)

Created by ome. Last Modification: Monday 12 of January, 2009 06:39:52 GMT by ome.