Chroma key

Chroma key compositing, or chroma keying, is a visual effects/post-production technique for compositing (layering) two images or video streams together based on color hues (chroma range). The technique has been used heavily 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 color 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 color keying, colour-separation overlay (CSO; primarily by the BBC[3]), or by various terms for specific color-related variants such as green screen, and blue screen – chroma keying can be done with backgrounds of any color that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from most human skin colors. No part of the subject being filmed or photographed may duplicate the color used as the backing.[4]

It is commonly used for weather forecast broadcasts, wherein a news presenter is usually seen standing in front of a large CGI map during live television newscasts, though in actuality it is a large blue or green background. When using a blue screen, different weather maps are added on the parts of the image where the color is blue. If the news presenter wears blue clothes, his or her clothes will also be replaced with the background video. Chroma keying is also common in the entertainment industry for visual effects in movies and video games.

Green screens compare with Iman Crosson 20110524
Today's practicality of green-screen compositing is demonstrated by Iman Crosson in a self-produced YouTube video.
Top panel: A frame of Crosson in full-motion video as shot in his own living room.[1]
Bottom panel: Frame in the final version, in which Crosson, impersonating Barack Obama, "appears" in the White House's East Room.[2]

History

Predecessors

Prior to the introduction of travelling mattes and optical printing, double exposure was used to introduce elements into a scene which were not present in the initial exposure. This was done using black draping where a green screen would be used today. George Albert Smith first used this approach in 1898. In 1903, The Great Train Robbery by Edwin S. Porter used double exposure to add background scenes to windows which were black when filmed on set, using a garbage matte to expose only the window areas.[5]

In order to have figures in one exposure actually move in front of a substituted background in the other, a travelling matte was needed, to occlude the correct portion of the background in each frame. In 1918 Frank Williams patented a travelling matte technique, again based on using a black background. This was used in many films, such as The Invisible Man.[6]:4

In the 1920s, Walt Disney used a white backdrop to include human actors with cartoon characters and backgrounds in his Alice Comedies.[6]:5

Bluescreen

The blue screen method was developed in the 1930s at RKO Radio Pictures. At RKO, Linwood Dunn used an early version of the travelling matte to create "wipes" – where there were transitions like a windshield wiper in films such as Flying Down to Rio (1933). Credited to Larry Butler, a scene featuring a genie escaping from a bottle was the first use of a proper bluescreen process to create a traveling matte for The Thief of Bagdad (1940), which won the Academy Award for Best Special Effects that year. In 1950, Warner Brothers employee and ex-Kodak researcher Arthur Widmer began working on an ultraviolet travelling matte process. He also began developing bluescreen techniques: one of the first films to use them was the 1958 adaptation of the Ernest Hemingway novella, The Old Man and the Sea, starring Spencer Tracy.[7]

Petro Vlahos was awarded an Academy Award for his refinement of these techniques in 1964. His technique exploits the fact that most objects in real-world scenes have a color whose blue-color component is similar in intensity to their green-color component. Zbigniew Rybczyński also contributed to bluescreen technology. An optical printer with two projectors, a film camera and a 'beam splitter', was used to combine the actor in front of a blue screen together with the background footage, one frame at a time. In the early 1970s, American and British television networks began using green backdrops instead of blue for their newscasts. During the 1980s, minicomputers were used to control the optical printer. For the film The Empire Strikes Back, Richard Edlund created a 'quad optical printer' that accelerated the process considerably and saved money. He received a special Academy Award for his innovation.

For decades, travelling matte shots had to be done "locked-down", so that neither the matted subject nor the background could shift their camera perspective at all. Later, computer-timed, motion-control cameras alleviated this problem, as both the foreground and background could be filmed with the same camera moves.

Meteorologists on television often use a field monitor, to the side of the screen, to see where they are putting their hands against the background images. A newer technique is to project a faint image onto the screen.

Some films make heavy use of chroma key to add backgrounds that are constructed entirely using computer-generated imagery (CGI). Performances from different takes can be composited together, which allows actors to be filmed separately and then placed together in the same scene. Chroma key allows performers to appear to be in any location without leaving the studio. Computer development also made it easier to incorporate motion into composited shots, even when using handheld cameras. Reference-points can be placed onto the colored background (usually as a painted grid, X's marked with tape, or equally spaced tennis balls attached to the wall). In post-production, a computer can use the references to compute the camera's position and thus render an image that matches the perspective and movement of the foreground perfectly. Modern advances in software and computational power have eliminated the need to accurately place the markers – the software figures out their position in space (a disadvantage of this is that it requires a large camera movement, possibly encouraging modern film techniques where the camera is always in motion).

Process

SpiderwickChroniclesSet
Film set for The Spiderwick Chronicles, where a visual effects scene using bluescreen chroma key is in preparation

The principal subject is filmed or photographed against a background consisting of a single colour or a relatively narrow range of colours, usually blue or green because these colours are considered to be the farthest away from skin tone.[4] The portions of the video which match the pre-selected color are replaced by the alternate background video. This process is commonly known as "keying", "keying out" or simply a "key".

Processing a green backdrop

VirtuellesStudio Greenbox
Virtual television studio with green-screen technique. The high amount of contrast between different parts of the screen is not ideal (see even lighting). Green reflections from the desk would create undesirable artifacts.

Green is used as a backdrop for TV and electronic cinematography more than any other colour because television weathermen tended to wear blue suits. When chroma keying first came into use in television production, the blue screen that was then the norm in the movie industry was used out of habit, until other practical considerations caused the television industry to move from blue to green screens. Broadcast quality color television cameras use separate red, green and blue image sensors, and early analog TV chroma keyers required RGB component video to work reliably. From a technological perspective it was equally possible to use the blue or green channel, but because blue clothing was an ongoing challenge, the green screen came into common use. Newscasters sometimes forget the chroma key dress code, and when the key is applied to clothing of the same color as the background, the person would seem to disappear into the key. Because green clothing is less common than blue, it soon became apparent that it was easier to use a green matte screen than it was to constantly police the clothing choices of on-air talent. Also, because the human eye is more sensitive to green wavelengths, which lie in the middle of the visible light spectrum, the green analog video channel typically carried more signal strength, giving a better signal to noise ratio compared to the other component video channels, so green screen keys could produce the cleanest key. In the digital television and cinema age, much of the tweaking that was required to make a good quality key has been automated. However, the one constant that remains is some level of color coordination to keep foreground subjects from being keyed out.[8]

Processing a blue backdrop

Before electronic chroma keying, compositing was done on (chemical) film. The camera colour negative was printed onto high-contrast black and white film, using either a filter or the colour sensitivity of the black and white film to limit it to the blue channel. Assuming this film was a negative it produced clear where the blue matte screen was, black elsewhere, except it also produced clear for any white objects (since they also contained blue). Removing these spots could be done by a suitable double-exposure with the colour positive, and many other techniques. The end result was a clear background with an opaque shape of the subject in the middle. This is called a female matte, similar to an alpha matte in digital keying. Copying this film onto another high-contrast negative produced the opposite 'male matte'. The background negative was then packed with the female matte and exposed onto a final strip of film, then the camera negative was packed with the male matte was double-printed onto this same film. These two images combined together creates the final effect.

Major factors

The most important factor for a key is the color separation of the foreground (the subject) and background (the screen) – a blue screen will be used if the subject is predominantly green (for example plants), despite the camera being more sensitive to green light.

In analog color TV, color is represented by the phase of the chroma subcarrier relative to a reference oscillator. Chroma key is achieved by comparing the phase of the video to the phase corresponding to the pre-selected color. In-phase portions of the video are replaced by the alternate background video.

In digital color TV, color is represented by three numbers (red, green, blue intensity levels). Chroma key is achieved by a simple numerical comparison between the video and the pre-selected color. If the color at a particular point on the screen matches (either exactly, or in a range), then the video at that point is replaced by the alternate background.

Lighting

In order to create an illusion that characters and objects filmed are present in the intended background scene, the lighting in the two scenes must be a reasonable match. For outdoor scenes, overcast days create a diffuse, evenly colored light which can be easier to match in the studio, whereas direct sunlight needs to be matched in both direction and overall color based on time of day.

A studio shot taken in front of a green screen will naturally have ambient light the same color as the screen, due to its light scattering. This effect is known as spill.[6]:p20 This can look unnatural or cause portions of the characters to disappear, so must be compensated for, or avoided by using a larger screen placed far from the actors.[9]

Camera

The depth of field used to record the scene in front of the colored screen should match that of the background. This can mean recording the actors with a larger depth of field than normal.[10]

Clothing

Girl wearing blue clothing in front of green screen. The shadows cast onto the green screen are not ideal (see even lighting.)

Girl in front of a green background
Girl in room, green screen example

A chroma key subject must avoid wearing clothes which are similar in color to the chroma key color(s) (unless intentional e.g., wearing a green top to make it appear that the subject has no body), because the clothing may be replaced with the background image/video. An example of intentional use of this is when an actor wears a blue covering over a part of his body to make it invisible in the final shot. This technique can be used to achieve an effect similar to that used in the Harry Potter films to create the effect of an invisibility cloak. The actor can also be filmed against a chroma-key background and inserted into the background shot with a distortion effect, in order to create a cloak that is marginally detectable.[11]

Difficulties emerge with blue screen when a costume in an effects shot must be blue, such as Superman's traditional blue outfit. In the 2002 film Spider-Man, in scenes where both Spider-Man and the Green Goblin are in the air, Spider-Man had to be shot in front of the green screen and the Green Goblin had to be shot in front of a blue screen. The color difference is because Spider-Man wears a costume which is red and blue in color and the Green Goblin wears a costume which is entirely green in color. If both were shot in front of the same screen, parts of one character would be erased from the shot.

For a clean division of foreground from background, it is also important that clothing and hair in the foreground shot have a fairly simple silhouette, as fine details such as frizzy hair may not resolve properly. Similarly, partially transparent elements of the costume cause problems.[10]

Background color

MuseumOfScienceBoston BlueScreenAtSpecialEffectsShow
Demonstration of the creation of visual effects techniques utilizing chroma key

Blue was originally used for TV chroma keying special effects because human skin tone contains very little blue, and because the film industry used blue backgrounds for similar purposes. The color blue was tied to the blue emulsion layer of film having comparable grain and detail in comparison to the red and green layers of the emulsion. In television and digital filmmaking, however, green has become the favored color because of some practical considerations, and because lossy compression algorithms used in both analog and digital TV distribution retain more detail in the green channel. The choice of color is up to the effects artists and the needs of the specific shot. Whereas the blue screen was introduced to the television industry by the film industry, the use of green screen visual effects has been introduced to the film industry as electronic imaging has augmented and replaced the use of chemical film stock in cinema. Also, the green background is favored over blue for outdoor filming where the blue sky might appear in the frame and could accidentally be replaced in the process. Although green and blue are the most common in part because red, green and blue components are used to encode the visible light spectrum, any key color can be used. Red is avoided for human subjects due to its prevalence in white skin tones, but can be often used for objects and scenes which do not involve people.

So-called "yellow screen" is accomplished with a white backdrop. Ordinary stage lighting is used in combination with a bright yellow sodium lamp. The sodium light falls almost entirely in a narrow frequency band, which can then be separated from the other light using a prism, and projected onto a separate but synchronized film carrier within the camera. This second film is high-contrast black and white, and is processed to produce the matte.[6]:16

Occasionally, a magenta background is used, as in some software applications where the magenta or fuchsia is sometimes referred to as "magic pink".[12]

A newer technique is to use a retroreflective curtain in the background, along with a ring of bright LEDs around the camera lens. This requires no light to shine on the background other than the LEDs, which use an extremely small amount of power and space unlike big stage lights, and require no rigging. This advance was made possible by the invention in the 1990s of practical blue LEDs, which also allow for emerald green LEDs.

There is also a form of color keying that uses light spectrum invisible to human eye. Called Thermo-Key, it uses infrared as the key color, which would not be replaced by background image during postprocessing.[13][14]

For Star Trek: The Next Generation, an ultraviolet light matting process was proposed by Don Lee of CIS Hollywood and developed by Gary Hutzel and the staff of Image G. This involved a fluorescent orange backdrop which made it easier to generate a holdout matte, thus allowing the effects team to produce effects in a quarter of the time needed for other methods.[15]

In principle, any type of still background can be used as a chroma key instead of a solid color. First the background is captured without actors or other foreground elements; then the scene is recorded. The image of the background is used to cancel the background in the actual footage; for example in a digital image, each pixel will have a different chroma key. This is sometimes referred to as a difference matte.[16] However, this makes it easy for objects to be accidentally removed if they happen to be similar to the background, or for the background to remain due to camera noise or if it happens to change slightly from the reference footage.[17] A background with a repeating pattern alleviates many of these issues, and can be less sensitive to wardrobe color than solid-color backdrops.[18]

Tolerances

Even lighting

Myx tv
A live broadcast of Myx TV using green-screen chroma key. Note the lack of shadows on the screen. The whiter area near the center of the image is due to the angle this photo was taken from, and would not appear from the video camera's angle.

The biggest challenge when setting up a bluescreen or greenscreen is even lighting and the avoidance of shadow, because it is best to have as narrow a color range as possible being replaced. A shadow would present itself as a darker color to the camera and might not register for replacement. This can sometimes be seen in low-budget or live broadcasts where the errors cannot be manually repaired. The material being used affects the quality and ease of having it evenly lit. Materials which are shiny will be far less successful than those that are not. A shiny surface will have areas that reflect the lights making them appear pale, while other areas may be darkened. A matte surface will diffuse the reflected light and have a more even color range. In order to get the cleanest key from shooting greenscreen it is necessary to create a value difference between the subject and the greenscreen. In order to differentiate the subject from the screen, a two-stop difference can be used, either by making the greenscreen two stops higher than the subject, or vice versa.

Sometimes a shadow can be used to create a visual effect. Areas of the bluescreen or greenscreen with a shadow on them can be replaced with a darker version of the desired background video image, making it look like the person is casting a shadow on them. Any spill of the chroma key color will make the result look unnatural. A difference in the focal length of the lenses used can affect the success of chroma key.

Exposure

Another challenge for bluescreen or greenscreen is proper camera exposure. Underexposing or overexposing a colored backdrop can lead to poor saturation levels. In the case of video cameras, underexposed images can contain high amounts of noise, as well. The background must be bright enough to allow the camera to create a bright and saturated image.

Programming

There are several different quality- and speed-optimized techniques for implementing color keying in software.[19][20]

In most versions, a function f(r, g, b) → α is applied to every pixel in the image. α (alpha) has a meaning similar to that in alpha compositing techniques. α ≤ 0 means the pixel is fully in the green screen, α ≥ 1 means the pixel is fully in the foreground object, and intermediate values indicate the pixel is partially covered by the foreground object (or it is transparent). A further function g(rgb) → (rgb) is needed to remove green spill on the foreground objects.

A very simple f() function for green screen is A(r+b) − Bg where A and B are user adjustable constants with a default value of 1.0. A very simple g() is (r, min(g,b), b). This is fairly close to the capabilities of analog and film-based screen pulling.

Modern examples[20] of these functions are best described by two closed nested surfaces in 3-D rgb space, often quite complex. Colors inside the inner surface are considered green screen. Colors outside the outer surface are opaque foreground. Colors between the surfaces are partially covered, they are more opaque the closer they are to the outer surface. Sometimes more closed surfaces are used to determine how to remove green spill. It is also very common for f() to depend on more than just the current pixel's color, it may also use the (xy) position, the values of nearby pixels, the value from reference images or a statistical color model of the scene,[21] and values from user-drawn masks. These produce closed surfaces in space with more than three dimensions.

A different class of algorithm tries to figure out a 2D path that separates the foreground from the background. This path can be the output, or the image can be drawn by filling the path with α = 1 as a final step. An example of such an algorithm is the use of active contour. Most research in recent years has been into these algorithms.

See also

References

  1. ^ From YouTube video "President Obama on Death of Osama SPOOF- BEHIND THE SCENES" (WebCite archive) posted to Crosson's secondary YouTube channel "Iman" on 8 May 2011.
  2. ^ The final (composite) video "President Obama on Death of Osama bin Laden (SPOOF)" (WebCite archive) posted to Crosson's YouTube channel "Alphacat" on 4 May 2011.
  3. ^ "What is Chroma Key?". Lumeo. Retrieved 3 July 2014.
  4. ^ a b "The Chroma Effect". Chroma Key Tutorial. BorisFX. Archived from the original on 15 March 2005. Retrieved 11 January 2010. If the foreground is a person then blue or green backing colour is recommended as these colours are not present in human flesh pigments. In fact, human skin colour is 70% red for all people regardless of race.
  5. ^ Kathryn Ramey. Experimental Filmmaking: Break the Machine. p. 70.
  6. ^ a b c d Foster, Jeff (2010). The Green Screen Handbook: Real-World Production Techniques. John Wiley & Sons. ISBN 978-0-470-52107-6.
  7. ^ "Illusions Take Home First Oscars". CRI English. 14 February 2005. Archived from the original on 15 March 2005. Retrieved 21 January 2009.
  8. ^ "The Keys To Chromakey: How To Use A Green Screen". Videomaker. Retrieved 23 October 2017.
  9. ^ Aronson, David (2006). DV Filmmaking: From Start to Finish, Volume 1. O'Reilly Media, Inc. pp. 52–53. ISBN 0596008481.
  10. ^ a b Bermingham, Alan (2013). Location Lighting for Television. Focal Press. p. 42. ISBN 0-240-51937-X.
  11. ^ "Creating an invisible cape in After Effects". Library.creativecow.net. Retrieved 20 July 2011.
  12. ^ "So you wanna make a theme?". skinyourscreen.com articles. Archived from the original on 29 October 2007. Retrieved 23 August 2008.
  13. ^ "What is Thermo-Key?". University of Tokyo. Archived from the original on 21 February 2009. Retrieved 21 January 2009.
  14. ^ Yasuda, K.; Naemura, T.; Harashima, H. (2004). "Thermo-key: human region segmentation from video". IEEE Computer Graphics and Applications. 24 (1): 26–30. doi:10.1109/MCG.2004.1255805. PMID 15384664. Retrieved 21 January 2009.
  15. ^ Sternbach, Rick; Okuda, Michael (1991). Star Trek: The Next Generation Technical Manual. Pocket Books. p. 13. ISBN 0-671-70427-3.
  16. ^ Steve Wright (22 November 2017). Digital Compositing for Film and Video: Production Workflows and Techniques. Taylor & Francis. p. 27. ISBN 978-1-315-28399-9.
  17. ^ Steve Wright (22 November 2017). Digital Compositing for Film and Video: Production Workflows and Techniques. Taylor & Francis. p. 29. ISBN 978-1-315-28399-9.
  18. ^ Yamashita, Atsushi; Agata, Hiroki; Kaneko, Toru (2008). "Every color chromakey". ICPR 2008. doi:10.1109/ICPR.2008.4761643.
  19. ^ Ashihkmin, Michael. "High Quality Chroma Key". University of Utah.
  20. ^ a b Cannon, Edward. "Greenscreen code and hints".
  21. ^ Aksoy, Yagiz; Aydin, Tunc; Pollefeys, Marc; Smolic, Aljoscha (2016). "Interactive High-Quality Green-Screen Keying via Color Unmixing". ACM Transactions on Graphics (TOG).

External links

Adobe Ultra

Adobe Ultra is a discontinued vector keying application, helping produce blue-screen/green-screen effects for video (although the background can actually be any color). Ultra performs complex image analysis to produce high quality chroma-key effects in less than ideal lighting environments. Ultra also included virtual set technology, which allows the keying of a subject into an animated virtual 3D environment.

Since its discontuation as a standalone product, the functionalities of Ultra have been incorporated into other Adobe products, namely Adobe Visual Communicator (since 2007), Adobe Premiere Elements (since 2008), and Adobe Premiere Pro (since 2010).

Ultra was previously known as Serious Magic Ultra Key, and was acquired when Adobe purchased Serious Magic Inc. in 2006. Unlike many of the other applications in the Adobe Creative Suite, Adobe Ultra only runs on the Windows operating system.

Color key

Usage of the terms color key, color keys, and the like may refer to:

Chroma key composition, a special effects technique layering images and/or video streams together

Colorist work and the materials used, adding details to black-and-white line art

Prepress proofing guides, used for fine-tuning items in printing presses

Colorblind (Chroma Key song)

Colorblind is the only single released by ex-Dream Theater Keyboardist Kevin Moore, under his standard recording name, Chroma Key. The standard edit of Colorblind can be found as track 1 of the album Dead Air for Radios. The CD contains 6 tracks, including the feature radio edit single of Colorblind, along with radio edits of two other tracks from the same album (On the Page and Even the Waves.) The CD also contains demo versions of the two aforementioned tracks, as well as a demo of a song called "Blanket", which did not appear on the album. The CD very rare and nearly impossible to buy, but a download version is available via the official website. This download edition features 3 bonus tracks, which are the 3 tracks from the original 1995 Chroma Key Demo. This Demo features demo versions of "On the Page", "Watercolor" and "Chroma Key". The demo version of "On the Page" found on the CD proper differs from the original 1995 demo version, found on the download version of the single.

Compositing

Compositing is the combining of 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.

D-2 (video)

D-2 is a professional digital videocassette format created by Ampex and introduced on 1988 at the NAB Show as a composite video alternative to the component video D-1 format. It garnered Ampex a technical Emmy in 1989. Like D-1, D-2 stores uncompressed digital video on a tape cassette; however, it stores a composite video signal, rather than component video as with D-1. While component video is superior for advanced editing, especially when chroma key effects are used, composite video is more compatible with most existing analog facilities.

Dead Air for Radios

Dead Air for Radios studio album by Kevin Moore, under the musical moniker Chroma Key. It was released through Fight Evil Records on December 16, 1998. The album was recorded by Steve Tushar at Bill's Place Rehearsal Studio in Hollywood, mixed by both Steve Tushar and Kevin Moore with final mastering by Eddy Schreyer. Since its release the album has sold around 10,000 copies.

Graveyard Mountain Home

Graveyard Mountain Home is the third studio album released under the name Chroma Key by American keyboardist Kevin Moore. It was released on November 8, 2004 by InsideOut Music. Moore originally started work on the album in 2003, planning to release a less electronica-influenced album than previous Chroma Key albums, but put it aside to work on the first OSI album. He then moved to Istanbul, Turkey, where he wrote Ghost Book, the soundtrack to the film Okul. Enjoying the experience of writing music to film, Moore scrapped his previous plans for the third Chroma Key album, instead writing an album as an alternate soundtrack to an already-existing film.

Moore found the social guidance film Age 13 in the Prelinger Archives, which served as his main inspiration. He slowed the film down to half its original playback speed to allow a full album to be written around the twenty-five-minute film. With complete creative control over the album, Moore was free to experiment, sometimes writing music "not necessarily to always match the images on the screen, but to sometimes play against it." The deluxe edition of the album contains the film in its full length, played at half speed, with the album as a soundtrack in place of the original audio.

Critical reception of Graveyard Mountain Home was generally positive. Critics noted that the album was a departure from Moore's previous works, and that it was best experienced as an alternate soundtrack to Age 13. Moore played songs from Graveyard Mountain Home live for the first time in a small club in Istanbul in 2007, and planned to tour more extensively in the future.

Green screen (disambiguation)

Green screen compositing, or more generally chroma key compositing, is a technique for combining two still images or video frames.

Green screen may also refer to:

Green-screen display, a monochrome CRT computer display

GreenScreen Interactive Software, a publisher of video games

Green screen of death, a failure mode on the TiVo digital video recorder and Xbox 360 console game system platforms

Green Screen film festival, a film festival in Germany

GreenScreen for Safer Chemicals a green chemicals assessment tool.

Drew Carey's Green Screen Show, an American improvisational show using a green screen

Jim Matheos

Jim Matheos (born November 22, 1962) is an American guitarist and the primary songwriter for the progressive metal band Fates Warning, in which he has been the only consistent member since the group's beginning. Matheos also plays in OSI alongside Kevin Moore (Chroma Key, ex-Dream Theater), as well as making other appearances with many different bands and artists.

He has also released two solo instrumental albums on Metal Blade Records.In 2003, Matheos collaborated with original Fates Warning vocalist John Arch on 2003's A Twist of Fate, Arch's first professional recording since leaving Fates Warning in 1987. The two later collaborated as Arch/Matheos, releasing a full-length album entitled Sympathetic Resonance in 2011.

Fates Warning has released twelve studio albums since their formation in 1982. Their latest album, Theories of Flight, was released in 2016.

On February 17, 2014, Matheos released an experimental guitar album called Halo Effect. It was released by the independent record label Burning Shed.

Joey Vera

Joseph "Joey" Vera (born April 24, 1963) is an American heavy metal bassist who is known as a member of the heavy metal band Armored Saint and the progressive metal band Fates Warning. In 2004-2005 he replaced Frank Bello in Anthrax as the band's bassist, but did not record with them. He was also a member of Engine, recorded with Tribe After Tribe, and appears on the OSI album Free. His first solo album, A Thousand Faces, was released in 1994. His current solo project, A Chinese Firedrill, released an album titled Circles in 2007.

Kevin Moore

Kevin Moore (born May 26, 1967) is an American keyboardist, vocalist, composer, and founder of the Chroma Key music project. He is also a former member of the American progressive metal/rock band Dream Theater, co-founder of the progressive rock supergroup O.S.I., and has composed film soundtracks. Throughout his career, he has become known for his emotional music and lyrics, nomadic lifestyle and use of spoken word samples.

Moore started his music career in progressive metal band Dream Theater. He contributed music and lyrics to the band's first three studio albums, but left the band during the recording of Awake to pursue his own musical interests. Starting with 1998's Dead Air for Radios, he has released electronica, ambient music through his solo project Chroma Key. Moore has guested on several albums, including three Fates Warning albums. This led Moore to form OSI with Fates Warning guitarist Jim Matheos in 2002, a band which combines progressive metal with electronica. The fourth OSI album, Fire Make Thunder, was released in March 2012.

Moore has worked on other solo projects since leaving Dream Theater. While living in Costa Rica, he produced a bi-weekly radio program for Radio for Peace International; a compilation of this work was released as Memory Hole 1. While living in Turkey, Moore produced the debut album of Turkish band Makine and wrote soundtracks for two Turkish films. The soundtrack for the first film, Okul, was released in 2004 as Ghost Book. The soundtrack for the second film, Küçük Kiyamet, entitled Shine, was released in 2010.

Mark Zonder

Mark Zonder (born 16 April 1958) is the drummer of American heavy-metal band Warlord. When the band was in a hiatus, he joined Fates Warning. His artistic name in Warlord is "Thunder Child". He also has his own band Slavior.

He also plays drums on Joacim Cans' solo-project album "Beyond The Gates", and with Kevin Moore's band Chroma Key. He has also worked with Gary Hughes and the rest of the band Ten on their studio album named Stormwarning, which was released in early 2011.

He has also collaborated to a classic metal project called Dramatica, featuring Dennis Murcia and Diego Ramirez of Texas early 90s metal band Decadence, and Mark Boals and Michael Vescera from Yngwie Malmsteen fame. The project is due out in the fall 2015.

OSI (band)

OSI is an American progressive rock band, originally formed by Fates Warning guitarist Jim Matheos in 2002. Chroma Key keyboardist and vocalist Kevin Moore is the only other full-time member of the band. The collaboration may be considered a studio project, as its members and contributors write and track most of their material independently, sharing and developing tracks long-distance, only coming together at the end of the process for mixing and additional tracking. The band's name is a reference to the Office of Strategic Influence, a short-lived American government agency formed in 2001 to support the War on Terror through propaganda. The band has featured a number of guest musicians on its albums, including Sean Malone, Steven Wilson, "Mikael", Joey Vera and Gavin Harrison.

Matheos recruited Moore, Dream Theater's then-drummer Mike Portnoy, and Sean Malone (Fretless Bass and Chapman Stickist) to perform on what was originally planned to be a Matheos solo album. Matheos and Portnoy originally planned to produce a progressive metal album similar to Matheos' work in Fates Warning, however Moore's impact changed the music's direction and genre, incorporating electronica into the original progressive metal sound. The band's debut album was released by InsideOut Music in 2003.

OSI was originally intended to be a one-off project, but Matheos and Moore found they both had gaps in their schedules so produced a follow-up. Free was released in 2006, with Portnoy returning to play drums as a session musician rather than a full band member, due to personal and musical differences between him and Moore. Blood was released in 2009, with Porcupine Tree drummer Gavin Harrison replacing Portnoy. The fourth album Fire Make Thunder was released in 2012 by Metal Blade Records, with Harrison once again on drums.

Primatte chromakey technology

Primatte is a brand of chroma key software 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.

Special Effects Stage

Special Effects Stage is an attraction at Universal Studios Hollywood. The attraction serves as a new version of the park's former Special Effects Stages show, which was located in the Lower Lot area and was relocated to the Upper Lot’s Castle Theater to make way for Transformers: The Ride. The attraction takes guests through demonstrations of how movie special effects are created, including Motion capture, Chroma key, and Stop motion techniques. It opened on June 26, 2010.

Virtual studio

The term virtual studio can refer to any number of technological tools which seek to simulate a physical television and/or movie studio. One such use of the term follows.

A virtual studio is a television studio that allows the real-time combination of people or other real objects and computer generated environments and objects in a seamless manner. A key point of a virtual studio is that the real camera can move in 3D space, while the image of the virtual camera is being rendered in real-time from the same perspective, therefore, this virtual scene has to adapt at any time to the camera settings (zoom, pan, angle, traveling, etc.). This is what differentiates a virtual studio from the traditional technique of chromakey. It also differs from techniques used in film, in which scenes are edited later. A virtual studio does not need any post production because it is in real-time. However a 3-D graphic artist and 3D computer graphics software are needed to create the virtual background, and any graphics that appear in front.

There exist many technical solutions for creating virtual studios, but most of them include the following components:

Camera tracking, that uses either optical or mechanical measurements to create a live stream of data describing the exact perspective of the camera.

Realtime rendering software, that uses the camera tracking data and generates a synthetic image of a television studio.

A video mixer, which combines the video from the camera with the video from the realtime rendering software to produce a final video output. One of the most common ways to mix the video to replace a chroma key background.A major difference between a virtual studio and the bluescreen special effects used in movies is that the computer graphics are rendered in realtime, removing the need for any post production work, and allowing it to be used in live television broadcasts.

You Go Now

You Go Now is the second solo album by keyboardist Kevin Moore, former member of Dream Theater. Moore recorded and released this album under the name Chroma Key. A number of initial pre-orders for the album in the Summer of 2000 were signed by Moore.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.