Click here

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.



Top Terms
  • 1

    private cloud project

    Companies initiate private cloud projects to enable their IT infrastructure to become more capable of quickly adapting to continually evolving...

    Read more »

  • 2

    cloud backup

    A cloud backup (cloud computer backup) refers to backing up data to a remote, cloud-based server. As a form of cloud storage, cloud backup data is...

    Read more »

  • Click Here!

Connect with Webopedia

  • Android Apps for Remote Computer Access

    Remote access is useful when you need to collaborate with co-workers, help a friend with PC problems or grab files from your desktop.

    Read More »

Did You Know? Archive »

  • Quick Reference Archive »