VIDEO STABILIZATION SYSTEM AND
This application is a Continuation of application Ser. No. 08/455,582, filed May 31, 1995, now abandoned. 5
CROSS-REFERENCE TO RELATED
This application is related to U.S. patent application Ser.
No. 08/382,274 entitled Smooth Panning Virtual Reality 10
Display System, filed Jan. 31, 1995 of the same assignee,
attorney docket number. TI-16702 (32350-1019).
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to the field of video recordings, and more particularly to a system and method for stabilizing video recordings.
BACKGROUND OF THE INVENTION
The use of video recorders or cameras continues to grow in this country. Millions of people use their video cameras each day to capture personal events in their lives and sometimes, newsworthy events. Unfortunately, some video camera users have difficulties maintaining the camera stable 25 during recording. This instability sometimes results in poor quality videos and can result in unwatchable videos. These problems may be exacerbated when the event being recorded contains action, such as a child's soccer game, or when the event is filmed under stress, such as when filming 30 an accident.
One previous attempt to stabilize video recordings has been to stabilize the optics portion of the video camera. By providing the optics with the ability to float with respect to the remainder of the camera during movement of the 35 camera, a more stable video recording can be captured. Unfortunately, optical solutions for stabilizing video recordings may be expensive. The hardware required to stabilize the optics may add significant costs to the camera, making the camera too expensive for large portions of the camera market.
Another prior approach to video stabilization has been to use a larger charged couple device (CCD) in the camera than is required to capture the scene being recorded. The portion of the CCD that is used to record a scene changes as required to stabilize the recording of the scene. For example, a sudden 45 downward movement of the camera can be compensated for by changing the portion of the CCD used to capture the scene from the center portion to the top portion of the CCD. Changing the portion of the CCD used to capture a scene removes the camera movement from the recording. 50 Unfortunately, a larger CCD and associated circuitry add costs to a video camera that may make the camera cost prohibitive for some users.
One shortcoming of known previously developed video stabilization techniques is that stabilization must be pro- 55 vided during recording. A need exists of techniques or systems that can stabilize a video recording after it has been made.
audio data. The method for stabilizing a video recording may include the steps of detecting camera movement occurring during recording and modifying the video data to compensate for the camera movement.
Another aspect of the present invention may include a system for stabilizing a video recording of a scene made with a video camera. The video recording may include video data and audio data. The system may include source frame storage for storing source video data as a plurality of sequential frames. The system may also include a processor for detecting camera movement occurring during recording and for modifying the video data to compensate for the camera movement. Additionally the system may include destination frame storage for storing the modified video data as plurality of sequential frames.
The present video stabilization system and method provide several technical advantages. One important technical advantage of the present invention is its ability to stabilize previously recorded video recordings. Millions of previously recorded video recordings can be stabilized with the present invention to enhance their quality. The present invention provides a relatively low cost solution for stabilizing video recordings in comparison with previously developed video stabilization techniques. The present invention can also be implemented in a video camera so that a video recording can be stabilized as it is made.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein:
FIG. 1 illustrates several frames from a video recording and the results of several camera movements;
FIG. 2 is a schematic block diagram of an example embodiment for the present stabilization system;
FIG. 3 provides a top level flow chart for a method for stabilizing a video recording in accordance with the present invention;
FIG. 4 is a flow chart for motion estimation in accordance with the present system and method;
FIGS. 4A through 4C depict examples of the use of needle maps for detecting various types of motion in a video scene;
FIG. 5 is a flow chart for warping a scene in accordance with the present invention;
FIG. 6 is a flow chart for interpolation of a scene in accordance with the present system and method;
FIGS. 7A and 7B illustrate warping an image;
FIG. 8 illustrates bilinear interpolation of an image;
FIG. 9 provides pipelining of address generation, input packet requests, interpolation, and output packet requests for pipelined transfer processor operations of the multimedia video processor in accordance with the present invention; and
FIGS. 10 through 12 illustrate the effects of stabilizing a scene in accordance with the present invention.
DETAILED DESCRIPTION OF THE
Preferred embodiments of the present invention are illustrated in the drawings, like numerals being used to refer to like and corresponding parts of various drawings.
FIG. 1 illustrates several frames from a video recording. Frame 1 includes scene 10 having vehicle 12 and mountain 14. In scene 10 vehicle 12 has not yet reached mountain 14. In frame 2 vehicle 12 is directly in front of mountain 14 in