alpha channel
in video and computer graphics, an extra signal, bit or set of bits used to control special effects such as transparency and overlay | ||||
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Alpha Channel definition was found in categories: Computer & Internet(3) Encyclopedia(1)
Alpha Channel Definition from Computer & Internet Dictionaries & Glossaries
| Digital Video (DV) & video edit terms / Eng2Eng v1.0 (web compilation) |
Alpha Channel
An 8-bit color channel (see channels) which is used to specify the transparency of each pixel in an image. An alpha channel works like a sophisticated stencil, and is the digital equivalent of a matte (see matte).
An 8-bit color channel (see channels) which is used to specify the transparency of each pixel in an image. An alpha channel works like a sophisticated stencil, and is the digital equivalent of a matte (see matte).
alpha channel
Information attached to each pixel that represents how that pixel is to be blended with background.
| Internet Glossary |
Alpha channel
In graphics, a portion of each pixel's data that is reserved for transparency information. 32-bit graphics systems contain four channels -- three 8-bit channels for red, green, and blue (RGB) and one 8-bit alpha channel. The alpha channel is really a mask -- it specifies how the pixel's colors should be merged with another pixel when the two are overlaid, one on top of the other.
Typically, you wouldn't define the alpha channel on a pixel-by-pixel basis, but rather per object. Different parts of the object would have different levels of transparency depending on how much you wanted the background to show through. This allows you to create rectangular objects that appear as if they are irregular in shape -- you define the rectangular edges as transparent so that the background shows through. This is especially important for animation, where the background changes from one frame to the next.
Rendering overlapping objects that include an alpha value is called alpha blending.
In graphics, a portion of each pixel's data that is reserved for transparency information. 32-bit graphics systems contain four channels -- three 8-bit channels for red, green, and blue (RGB) and one 8-bit alpha channel. The alpha channel is really a mask -- it specifies how the pixel's colors should be merged with another pixel when the two are overlaid, one on top of the other.
Typically, you wouldn't define the alpha channel on a pixel-by-pixel basis, but rather per object. Different parts of the object would have different levels of transparency depending on how much you wanted the background to show through. This allows you to create rectangular objects that appear as if they are irregular in shape -- you define the rectangular edges as transparent so that the background shows through. This is especially important for animation, where the background changes from one frame to the next.
Rendering overlapping objects that include an alpha value is called alpha blending.
| Digital Imaging, Pre-Press & Desktop Publishing |
Alpha Channel
is a mask channel in addition to the three Red, Green, & Blue image channels that can be used to isolate a particular area of an image in order for the computer to perform operations on that particular area. Alpha channels are used to describe silhouettes that have soft edges. (see: Clipping Path
is a mask channel in addition to the three Red, Green, & Blue image channels that can be used to isolate a particular area of an image in order for the computer to perform operations on that particular area. Alpha channels are used to describe silhouettes that have soft edges. (see: Clipping Path
Alpha Channel Definition from Encyclopedia Dictionaries & Glossaries
| Wikipedia English - The Free Encyclopedia |
Alpha compositing
In computer graphics, alpha compositing is the process of combining an image with a background to create the appearance of partial transparency. It is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image in a process called compositing. For example, compositing is used extensively when combining computer rendered image elements with live footage.
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