United States Patent  [li] Patent Number: 4,797,836
Witek et al.  Date of Patent: Jan. 10,1989
 IMAGE ORIENTATION AND ANIMATION USING QUATERNIONS
 Inventors: Francis A. Witek, Cedar Ridge;
David E. Lake, Jr., Penn Valley, both of Calif.
 Assignee: The Grass Valley Group, Inc., Grass Valley, Calif.
 Appl. No.: 932,805
 Filed: Nov. 19,1986
 Int. CI.* G06F 15/66; G09G 1/16
 U.S. Q 364/518; 340/725
 Field of Search 364/518, 522; 340/725,
 References Cited
U.S. PATENT DOCUMENTS
4,092,716 5/1978 Berg et al 364/424
4,134,681 1/1979 Elmer 356/152
4,600,919 7/1986 Stern 340/725
4,620,287 10/1986 Yam 364/518
4,625,289 11/1986 Rockwood 364/522
4,631,690 12/1986 Corthout et al 364/518
Primary Examiner—Gary V. Harkcom
Assistant Examiner—Randy W. Lacasse
Attorney, Agent, or Firm—Francis I. Gray
A method for orientating and animating video images using quaternions to provide smooth, predictable rotations in a digital video effect device. Euler angles for a new orientation are input by an operator and are converted into an appropriate quaternion. For incremental orientation changes the appropriate quaternion is combined with the current quaternion of the video image in either source or target space to form a new quaternion for the new orientation of the video image. A. selected plurality of such new quaternions in a sequence make up the video effect keyframes. In executing the video effect a Bezier spherical linear algorithm is used to interpolate intermediate quaternions on a video field by field basis between neighboring pairs of keyframe quaternions based upon the source keyframe quaternion, the destination keyframe quaternion, a source outgoing keyframe quaternion, a destination incoming keyframe quaternion and an inbetweening time coefficient. The intermediate quaternions are fine tuned by referring to tension, continuity and bias parameters.
21 Claims, 4 Drawing Sheets