How do they convert b/w films into colour?

  1. i've seen a film which was orignally black and white but after 50 years or so they made it colour. how did they do it?
  2. jcsd
  3. Danger

    Danger 9,663
    Gold Member

    They basically just 'paint' every element with the colour that they think belongs there. It's all pretty much computerized now, so things like shading remain undisturbed.
  4. But, how does the computer know if this particular dress was blue or say red?
    How are colours decided?
  5. Evo

    Staff: Mentor

    In some cases it might be known what color a famous dress was, but for most, they just arbitrarily pick a color.
  6. Astronuc

    Staff: Mentor

    There are sometimes color pictures (stills) for advertisements, or paintings of the actors or actresses in character.

    Otherwise, someone has to go off grey scales.
  7. color stills and movie posters
    plus popular colors at that time [or at the time of conversions]
    plus whatever ''they'' think looks good
    or read a grays scale of a known color [red rose] and convert other stuff to like colors
    as it is art not science what ever they want is the color it winds up being
  8. but a second has 25 frames, do they paint every frame? that will take enormous amount of time and money
  9. Danger

    Danger 9,663
    Gold Member

    It's certainly an involved process, but it's done digitally now. When thinking of doing it manually, though, don't forget that things like 'Fantasia' were not only coloured, but also drawn by hand... one frame at a time.
  10. wow, how much time does that take?
  11. Danger

    Danger 9,663
    Gold Member

    I can't find anything definitive. IIRC, there were at least a dozen artists working on Fantasia for a couple of years. It was originally supposed to be just Mickey Mouse directing 'The Sorceror's Apprentis', but they had to add the other pieces to make it profitable. It progressed in fits and starts.
    Snow White was in production for 3 years, but I don't know how much of that was the artwork or how many artists were involved.
    Last edited: Jun 15, 2007
  12. mgb_phys

    mgb_phys 8,809
    Science Advisor
    Homework Helper

  13. Danger

    Danger 9,663
    Gold Member

    Wow! I've tried to keep up with things, but I've sure never seen anything that sophisticated. Nice link.
  14. wow... ................................................................................
  15. Danger

    Danger 9,663
    Gold Member

  16. DaveC426913

    DaveC426913 16,534
    Gold Member

    Modern software is smart enough to track objects from frame to frame. So you tag one frame with the colours you want, and the computer does the rest. That's a huge simplification, but it's not like they have to colour every frame.
  17. Danger

    Danger 9,663
    Gold Member

    But, as the link mentions, it has to be checked every dozen frames or so. The process that Mgb phys brought up is way beyond what is currently being used commercially.
  18. Check out Legend Films, Inc. ( if you want to see the latest colorization technology. The company just completed "It's A Wonderful Life" in high definition for Paramount Pictures and will be released on standard DVD November 9th, 2007.

    The Legend Films process involves the separation of foreground and background elements in each cut of each scene (cut = a camera shot). The foreground elements (objects that move independently from the background) are colorized from a key frame (single fully designed frame) in each cut of a scene. The color (masks) is automatically transferred from one frame to the next (24 frames/sec in film) using new and very innovative pattern recognition algorithms. The backgrounds are processed separatedly as single frames. The Legend Films process elimintates all the foreground objects and creates a single frame that represents all the background elements. The single frame has all the information related to camera movement and parallax. Once the foreground elements are all colorized, the single background frame is used to automatically place the background color to all frames in the cut.

    Every frame must be colorized in this manner. Optimization is a fun way to colorize a single photograph but the process cannot provide the detail and pipeling thru-put to efficiently colorize an entire feature film containing more than 150,000 to 175,000 frames.

    The application of color is a one to one replacement of gray scale dynamic range with a range of color selected by a creative designer. Every object in each frame requires a color mask within which there is a spectrum of color designated for highlights, midtones and shadows.

    Hope this helps.


    Barry B. Sandrew, Ph.D.
    Founder/COO, CTO
    Legend Films, Inc.
  19. Danger

    Danger 9,663
    Gold Member

    Thanks, Barry. That's a great post. I don't have time right now to check out that site, but it looks very interesting.
  20. I believe they do it by shooting in red and green filters and putting the filterso together afterwords. If I am not mistaken, that makes it color.

    EDIT: nvm. I think Barry put me in my place.
  21. baywax

    baywax 2,002
    Gold Member

    So todays coloured b/w films are nothing like the hand tinted photos of the 1800s. Those were pretty cool too.

    Are coloured b/w films allowed anywhere in the south, or is there a separate theatre for those? ;)
    Last edited: Sep 18, 2007
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