Results tagged “alpha” from Final Cut Studio, Avid, Adobe, and Video Streaming

Alpha Channels and Transparency 3 (Back to the Basics series)

By Alex on August 20, 2008 2:03 PM | | TrackBacks (0)

Masks vs. Alphas

Alpha channels are our most sophisticated way to handle transparency, but they're by no means the only way.  We commonly use the term "Mask" to refer to something similar to the alpha channel above - that is to say, a full range of "see-through-ness" for each point.  Photoshop, for example, uses the term "Mask" to mean just that.  But more primitive incarnations of "image masks" in applications like DVDs and some still image files like GIFs use a different approach.

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Alpha Channels and Transparency 2 (Back to the Basics series)

By Alex on August 19, 2008 1:49 PM | | TrackBacks (0)

Alpha Channels

As we first start thinking about transparency in a computer sense, let's go back to the beginning of how computers think about our NTSC broadcast images.  You might remember that, for our purposes, a computer thinks about videos as a sequence of many individual images (frames).  It thinks about each frame as a big rectangular "quilt" of pixels, or individual dots of color - for our purposes, 720 dots wide and 480 dots tall.  And it thinks of each of those dots of color as the amount of red, green, and blue in the color.


B2B-Alpha3.png

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Alpha Channels and Transparency 1 (Back to the Basics series)

By Alex on August 18, 2008 3:00 PM | | TrackBacks (0)
Whether you're using titles, creating supers, or doing any other sort of compositing, you're trying to tell the computer to show some parts of an image but to hide other parts.  

I've been surprised by the number of folks who were never really taught how that process works from the computer's point of view.  After the jump, an easy little primer that may help you understand --

B2B-Alpha1.png

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Avid and Alpha Import Settings

By Mickey on April 21, 2008 11:17 PM | | TrackBacks (0)
avid alpha import.gif
Importing a picture or a Quick Time into your Avid editing system requires that you change some of the import settings. When you import alpha from an Avid QuickTime codec, select Alpha > Use Existing in the Import Settings dialog box. When alpha is imported from a non-Avid QuickTime codec, select Alpha > Invert Existing. This is because the Avid QuickTime codec inverts the alpha during the movie’s creation, saving time on import into your editing applications while not significantly adding to the creation time in a third-party program. This step will save you time and will also preserve the intended alpha setting. 

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