Chroma key compositing, or chroma keying, is a visual-effects and post-production technique for compositing (layering) two or more images or video streams together based on colour hues. The technique has been used in many fields to remove a background from the subject of a photo or video – particularly the newscasting, motion picture, and video game industries. A colour range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as colour keying, colour-separation overlay, or by various terms for specific colour-related variants such as green screen or blue screen; chroma keying can be done with backgrounds of any colour that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from any human skin colour. No part of the subject being filmed or photographed may duplicate the colour used as the backing, or the part may be erroneously identified as part of the backing.
Visual effects is the process by which imagery is created or manipulated outside the context of a live-action shot in filmmaking and video production. The integration of live-action footage and other live-action footage or CGI elements to create realistic imagery is called VFX.
Traditional animation is an animation technique in which each frame is drawn by hand. The technique was the dominant form of animation in cinema until the end of the 20th century, when there was a shift to computer animation in the industry, specifically 3D computer animation.
A sodium-vapor lamp is a gas-discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm.
Compositing is the process or technique of combining visual elements from separate sources into single images, often to create the illusion that all those elements are parts of the same scene. Live-action shooting for compositing is variously called "chroma key", "blue screen", "green screen" and other names. Today, most, though not all, compositing is achieved through digital image manipulation. Pre-digital compositing techniques, however, go back as far as the trick films of Georges Méliès in the late 19th century, and some are still in use.
The multiplane camera is a motion-picture camera that was used in the traditional animation process that moves a number of pieces of artwork past the camera at various speeds and at various distances from one another. This creates a sense of parallax or depth.
Anaglyph 3D is the stereoscopic 3D effect achieved by means of encoding each eye's image using filters of different colors, typically red and cyan. Anaglyph 3D images contain two differently filtered colored images, one for each eye. When viewed through the "color-coded" "anaglyph glasses", each of the two images reaches the eye it's intended for, revealing an integrated stereoscopic image. The visual cortex of the brain fuses this into the perception of a three-dimensional scene or composition.
Leopold Godowsky Jr. was an American violinist and chemist, who together with Leopold Mannes created the first practical color transparency film, Kodachrome.
Petro Vlahos was an American engineer and inventor, considered to be one of the pioneering scientific and technical innovators of the motion picture and television industries. He is remembered in particular for creating the Ultimatte process, which refined the colour process known as chroma keying. In recognition of his contributions, he was awarded multiple Oscars, as well as an Emmy Award.
Mattes are used in photography and special effects filmmaking to combine two or more image elements into a single, final image. Usually, mattes are used to combine a foreground image with a background image. In this case, the matte is the background painting. In film and stage, mattes can be physically huge sections of painted canvas, portraying large scenic expanses of landscapes.
A front projection effect is an in-camera visual effects process in film production for combining foreground performance with pre-filmed background footage. In contrast to rear projection, which projects footage onto a screen from behind the performers, front projection projects the pre-filmed material over the performers and onto a highly reflective background surface.
Reverse bluescreen is a visual effects technique pioneered by Jonathan Erland of Apogee Inc.(John Dykstra's company) for shooting the flying sequences in the film Firefox. Its objective is to enable the matting of subjects that confound the conventional process, such as those exhibiting reflective surfaces. It derives its name from the fact that it reverses, or inverts, the basic bluescreen process. Erland received a Scientific and Engineering Award from the Academy of Motion Picture Arts and Sciences for this technique.
In cinematography, bipacking, or a bipack, is the process of loading two reels of film into a camera, so that they both pass through the camera gate together. It was used both for in-camera effects and as an early subtractive colour process.
Color motion picture film refers both to unexposed color photographic film in a format suitable for use in a motion picture camera, and to finished motion picture film, ready for use in a projector, which bears images in color.
Primatte is a brand of chroma key software used in motion picture, television and photographic host applications to remove solid colored backgrounds 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.
The Prizma Color system was a color motion picture process, invented in 1913 by William Van Doren Kelley and Charles Raleigh. Initially, it was a two-color additive color system, similar to its predecessor, Kinemacolor. However, Kelley eventually transformed Prizma into a bi-pack color system that itself became the predecessor for future color processes such as Multicolor and Cinecolor.
Dye transfer is a continuous-tone color photographic printing process. It was used to print Technicolor films, as well as to produce paper colour prints used in advertising, or large transparencies for display.
Technicolor is a series of color motion picture processes, the first version dating back to 1916, and followed by improved versions over several decades.
The Williams process or Williams doublematting process is a matte creation technique patented by the American cinematographer Frank D. Williams in 1918. Unlike prior matte techniques, it allowed for the integration of the actors' movements with previously shot backgrounds.
Wadsworth Egmont Pohl was an American engineer and inventor who won a Technical Award in 1964, and was credited with the invention or development of the Sodium vapor process and the bluescreen process.
