Archive:Kdenlive/Manual/Effects/Alpha manipulation/da: Difference between revisions

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    ==== General Information about Alpha Manipulation  ====  
    ==== General Information about Alpha Manipulation  ====  


    In previous versions of Kdenlive (<17.04 ??) Alpha Manipulation effects  always needed to be used in combination with a [[Special:myLanguage/Kdenlive/Manual/Transitions/Composite|composite transition]] or an [[Special:myLanguage/Kdenlive/Manual/Transitions/Affine|Affine transition]] . This is because Alpha Manipulation has to do with manipulating the so called "alpha-channel" of images and videos. The alpha channel is data that describes how two images are to be combined (or composited) into one. So you needed a composite (or affine) transition on the timeline to tell '''Kdenlive''' that you are compositing the videos from two different tracks into one image.  
    Alpha Manipulation, more commonly known as Chroma Key compositing is an effect that changes the background of the picture to a different background the editor may want.


    However, in version 17.04 of kdenlive an option was introduced that automatically composited two tracks that have Alpha channel data in them.  You turn this feature on by selecting either [[Special:myLanguage/Kdenlive/Manual/Timeline/Editing#Track_Compositing_-_HighQuality|High Quality]] or or [[Special:myLanguage/Kdenlive/Manual/Timeline/Editing#Track_Compositing_-_Preview|Preview]] from the Compositing Option drop down found under the Project Bin. Select None from this drop down to turn this feature off.
    More information can be found on the pages for the effects themselves:
    {|
    | [[File:Two tracks no transition.png|left]] || This image shows two video tracks with no transition.<br />The project monitor shows how the upper track takes precedence when no transition is in play.
    |}
    <br/>


    {|
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Blue Screen|Chroma Key ]] (for simple chroma key effects)
    | [[File:Two tracks composite transition no alpha info.png|400px|left]] || This image shows two video tracks with a composite transition in place but with no alpha information to tell '''Kdenlive''' how to combine the images.<br />With a composite transition but no alpha info to describe how to composite the picture, the top track still takes precedence.
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Color Selection|Farvevalg]]
    |}


    {|
    | [[File:Two tracks composite transition with alpha info.png|400px|left]] || Dette billede viser situationen med alfainformation tilføjet ved hjælp af blå skærm-metoden.<br />Blå skærm-effekten kendes også som "Color to alpha" [http://www.mltframework.org/bin/view/MLT/FilterFrei0r-bluescreen0r]; alt hvad blå skærm-effekten gør er, at sørge for at alfaværdien er 0 (dvs. gennemsigtig) dere hvor videoen er blå.<br />Nu, hvor vi har alfainformation kan vi se det andet billede der hvor alfakanalen siger, at billedet skal være gennemsigtigt.
    |}


    Nå først du har nogle alfakanaldata kan du ændre indstillingerne for din [[Special:myLanguage/Kdenlive/Manual/Transitions/Composite|sammensatte overgang]] for at ændre, hvordan billederne kombineres. Se siden om [[Special:myLanguage/Kdenlive/Manual/Transitions/Composite|sammensatte overgange]] for detaljer.


    Du kan også kombinere to videospor ved hjælp af overgangen [[Special:myLanguage/Kdenlive/Manual/Transitions/screen|screen]] (hvis en af dem er filmet på en sort baggrund).
    ==== Tips til forhåndsvisning af alfamanipulationseffekter ====
    Forhåndsvisningen i projektmonitoren kan blive meget mærkelig, hvis du markerer den sammensatte overgang eller video 1 i tidslinjen. (Rapporteret som fejl [http://www.kdenlive.org/mantis/view.php?id=2990 2990] og rettet i ver >= 0.9.5 af Kdenlive)
    [[File:Weird preview look.png|400px|left]]
    Sådan ser projektmonitoren ud, når du bare markerer den sammensate overgang i tidslinjen. Det er ikke sådan den renderede video kommer til at se ud. For at se, hvordan videoen vil blive renderet til skal du klikke på Video 1 og så på Video 2 i tidslinjen.
    <br style="clear: both;"/>
    [[File:Two tracks composite transition with alpha info.png|400px|left]] Sådan kommer forhåndsvisningen til at se ud, når du også markerer Video 2 i tidslinjen. Det er sådan den renderede file kommer til at se ud
    <br style="clear: both;"/>
    <br />
    ==== Effekter i kategorien alfamanipulation ====


    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Alpha gradient|Alfagradient]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Alpha gradient|Alfagradient]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Alpha operations|Alfa-operationer]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Alpha operations|Alfa-operationer]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Alpha shapes|Alfaformer]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Alpha shapes|Alfaformer]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Blue Screen|Chroma Key ]] (formerly Blue Screen)
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Blue Screen|Chroma Key ]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Color Selection|Farvevalg]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Color Selection|Color Selection]]  
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Mask0Mate|Rectangular Alpha mask]] (Formerly Mask0Mate)
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Mask0Mate|Rectangular Alpha mask]]  
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Rotoscoping|Rotoscoping]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Rotoscoping|Rotoscoping]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Misc/keysplillm0pup|keys Spill Mop Up]]
    # [[Special:myLanguage/Kdenlive/Manual/Effects/Misc/keysplillm0pup|Key Spill Mop Up]]
     
     


    ==== Baggrundsmateriale om compositing ====
    ==== Baggrundsmateriale om compositing ====
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    {{Prevnext2
    {{Prevnext2
    | prevpage=Special:MyLanguage/Kdenlive/Manual/Effects| nextpage=Special:MyLanguage/Kdenlive/Manual/Effects/Audio
    | nextpage=Special:MyLanguage/Kdenlive/Manual/Effects/Analysis_and_Data
    | prevtext=Effekter | nexttext=Lyd
    | nexttext=Analysis and Data
    | index=Special:MyLanguage/Kdenlive/Manual | indextext=Indholdsfortegnelse
    | index=Special:MyLanguage/Kdenlive/Manual/Effects#Effects_Categories| indextext=Effects_Categories
    }}
    }}


    [[Category:Kdenlive/da]]
    [[Category:Kdenlive/da]]

    Revision as of 20:40, 31 March 2019

    Effekter - alfamanipulation

    General Information about Alpha Manipulation

    Alpha Manipulation, more commonly known as Chroma Key compositing is an effect that changes the background of the picture to a different background the editor may want.

    More information can be found on the pages for the effects themselves:

    1. Chroma Key (for simple chroma key effects)
    2. Farvevalg



    1. Alfagradient
    2. Alfa-operationer
    3. Alfaformer
    4. [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha manipulation/Blue Screen|Chroma Key ]
    5. Color Selection
    6. Rectangular Alpha mask
    7. Rotoscoping
    8. Key Spill Mop Up


    Baggrundsmateriale om compositing

    For noget baggrundsinformation (på engelsk) er Wikipediaartiklen alpha compositing nyttig. Se også Porter, Thomas; Tom Duff (1984). "Compositing Digital Images". Computer Graphics 18 (3): p253–259 1984 pdf