thornton@ssc-vax.UUCP (08/17/87)
Hello Amigans.
I'm thinking about taking the plunge, but have a question about
GENLOCK Keying. This is one feature that I don't fully understand
about this machine and want to figure out before I buy.
I want to overlay real images onto computer generated ones. I believe
the GENLOCK drops picture areas on the basis of color. This is a
bit primitive for me. I want to drop portions of the video signal
instead (i.e. shoot a picture of a person and drop everything except
the person, then place that person in my computer generated scene).
I may just have to digitize the real image and extract the features
I'm interested in, enter a "video editer", and place those features
in my artificial scene. I may also want to construct a 3D model of
my extracted feature (i.e. person), so that I can play with it.
Does anyone know of any software to do this? Does anyone know of
any other more-advanced GENLOCK units that can drop spatial areas
of a picture rather than areas based on color?
Ken
--
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/ / /\/ \ Ken Thornton {decvax,ihnp4}!uw-beaver!ssc-vax!ssc-bee!thornton
/ / / \ \ralph@lzfme.UUCP (R.BRANDI) (08/19/87)
In article <886@ssc-bee.ssc-vax.UUCP>, thornton@ssc-vax.UUCP (Ken Thornton) writes: > Hello Amigans. > (stuff...) > I want to overlay real images onto computer generated ones. I believe > the GENLOCK drops picture areas on the basis of color. This is a > bit primitive for me. I want to drop portions of the video signal > instead (i.e. shoot a picture of a person and drop everything except > the person, then place that person in my computer generated scene). > I believe that you have a faulty understanding of what the GENLOCK can do. GENLOCK drops the background color on the *computer* image, not on the video image that it imports. Because of this, you can overlay computer-generated images onto video, but not the other way around. There is a device that does the opposite; it is called Chroma-Key. This subtracts out a given color (usually blue, or less commonly, green) and places what remains on the background. This is what you would need to place a picture of someone or something *over* a computer-generated scene. Supposedly, there are or will be Chroma-keys available for the Amiga in the near future, but I don't have any of the details. Note that to do this, you would probably have to shoot your subject in front of a "Chroma-key screen", or a plain blue background, evenly lit. > I may just have to digitize the real image and extract the features > I'm interested in, enter a "video editer", and place those features > in my artificial scene. I may also want to construct a 3D model of > my extracted feature (i.e. person), so that I can play with it. > Digitizing the real image may be another way to do this without the Chroma-key. This also offers the advantage of being able to shoot your subject in front of any background. It is, however, *very* time consuming. > Ken > -- > /\ > /\/ \/\ > / / /\/ \ Ken Thornton {decvax,ihnp4}!uw-beaver!ssc-vax!ssc-bee!thornton > / / / \ \ ==== | Disclaimer: Just `cuz I work on the Death Star, ==OOO===== | That doesn't mean I speak for Darth Vader... =OOOOOOO==== | Ralph Brandi, {ihnp4,mhuxt}!homxb!mtuxo!lzfme!ralph =OOOOOOO==== | Kopykat (k) 1987, R.A.Brandi ==OOO===== | All Rights Reserved, All Jams Preserved, ==== | All Nasty Comments Soundly Deserved...