• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint

Keyframes

Many codecs—especially codecs designed for low data rates—use keyframes to optimize compression while maintaining the highest possible image quality. Keyframes are essential to a compression technique called frame differencing. (The term keyframe in this context has a different meaning than when it's used in reference to animation. See Chapter 11 and Chapter 14 for more information about using keyframes in animation.)

In frame differencing, keyframes act as reference frames, with which subsequent frames are compared. Rather than describe every frame completely, frame differencing achieves more efficient compression by describing only the changes between keyframes.


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint