Method and apparatus for temporal stabilization of streaming frames
View Patent ↗A method, apparatus and computer program product are disclosed to provide improved temporal stabilization of a control algorithm associated with the processing of streaming frames. In the context of a method, the number of immediately preceding consecutive frames during which a filtered value has been greater than a current value of the current frame is determined or the number of immediately preceding, consecutive frames during which the filtered value has been less than the current value of the current frame is determined. The method also includes determining a weight based upon the number of immediately preceding, consecutive frames. The weight is configured to vary in a direct relationship to the number of immediately preceding, consecutive frames. The method also determines a filtered value of a current frame based upon a combination of the weight and the difference between the prior filtered value and the value of the current frame.
1. A method comprising:
determining, with a processor, a number of preceding, consecutive frames during which a an associated filtered value has been greater than a current value of a current frame or the number of preceding, consecutive frames during which the associated filtered value has been less than the current value of the current frame, wherein determining the number of preceding, consecutive frames comprises maintaining a first counter of the number of preceding, consecutive frames during which the associated filtered value has been greater than the current value of the current frame or maintaining a second counter of the number of preceding, consecutive frames during which the associated filtered value has been less than the current value of the current frame;
determining a weight based upon the number of preceding, consecutive frames, wherein the weight varies in a direct relationship to the number of preceding, consecutive frames;
determining a filtered value of the current frame based upon a combination of the weight and a difference between a prior filtered value associated with a previous frame and the current value of the current frame; and
resetting at least one of the first and second counters in an instance in which the filtered value associated with the proceeding, consecutive frames equals or exceeds the current value of the current frame.
2. A method according to claim 1 further comprising reducing at least one of the first and second counters in an instance in which the filtered value associated with the proceeding, consecutive frames equals or exceeds the current value of the current frame.
3. A method according to claim 2 further comprising determining that the preceding, consecutive frames are ascending or determining that the preceding, consecutive frames are descending, wherein reducing at least one of the first and second counters comprises reducing, but not resetting, at least one of the first and second counters in an instance in which the preceding, consecutive frames are determined to be ascending or to be descending.
4. A method according to claim 1 further comprising determining a weight associated with the difference between the prior filtered value and the current value of the current frame, and wherein determining the filtered value of the current frame comprises determining the filtered value of the current frame based upon a combination of the plurality of weights and the current value of the current frame.
5. A method according to claim 4 further comprising combining the weight associated with the difference between the prior filtered value and the current value of the current frame and the weight based upon the number of preceding, consecutive frames.
6. A method according to claim 1 , where in the number of preceding consecutive frames comprises a number of immediately preceding, consecutive frames.
7. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the processor, cause the apparatus to at least:
determine a number of preceding, consecutive frames during which an associated filtered value has been greater than a current value of a current frame or the number of preceding, consecutive frames during which the associated filtered value has been less than the current value of the current frame, wherein the at least one memory and the computer program code are configured to, with the processor, cause the apparatus to determine the number of preceding, consecutive frames by maintaining a first counter of the number of preceding, consecutive frames during which the associated filtered value has been greater than the current value of the current frame or by maintaining a second counter of the number of preceding, consecutive frames during which the associated filtered value has been less than the current value of the current frame;
determine a weight based upon the number of preceding, consecutive frames, wherein the weight varies in a direct relationship to the number of preceding, consecutive frames;
determine a filtered value of the current frame based upon a combination of the weight and a difference between a prior filtered value associated with a previous frame and the current value of the current frame; and
reset at least one of the first and second counters in an instance in which the filtered value associated with the proceeding, consecutive frames equals or exceeds the current value of the current frame.
8. An apparatus according to claim 7 wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to reduce at least one of the first and second counters in an instance in which the filtered value associated with the proceeding, consecutive frames equals or exceeds the current value of the current frame.
9. An apparatus according to claim 8 wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to determine that the preceding, consecutive frames are ascending or to determine that the preceding, consecutive frames are descending, wherein the at least one memory and the computer program code are configured to, with the processor, cause the apparatus to reduce at least one of the first and second counters by reducing, but not resetting, at least one of the first and second counters in an instance in which the preceding, consecutive frames are determined to be ascending or to be descending.
10. An apparatus according to claim 7 wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to determine a weight associated with the difference between the prior filtered value and the current value of the current frame, and wherein the at least one memory and the computer program code are configured to, with the processor, cause the apparatus to determine the filtered value of the current frame by determining the filtered value of the current frame based upon a combination of the plurality of weights and the current value of the current frame.
11. An apparatus according to claim 7 wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to combine the weight associated with the difference between the prior filtered value and the current value of the current frame and the weight based upon the number of preceding, consecutive frames.
12. A computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program code portions stored therein, the computer-executable program code portions comprising program code instructions for:
determining a number of preceding, consecutive frames during which an associated filtered value has been greater than a current value of a current frame or the number of preceding, consecutive frames during which the associated filtered value has been less than the current value of the current frame, wherein the program code instructions for determining the number of preceding, consecutive frames comprise program code instructions for maintaining a first counter of the number of preceding, consecutive frames during which the associated filtered value has been greater than the current value of the current frame or program code instructions for maintaining a second counter of the number of preceding, consecutive frames during which the associated filtered value has been less than the current value of the current frame;
determining a weight based upon the number of preceding, consecutive frames, wherein the weight varies in a direct relationship to the number of preceding, consecutive frames;
determining a filtered value of the current frame based upon a combination of the weight and a difference between a prior filtered value associated with a previous frame and the current value of the current frame; and
resetting at least one of the first and second counters in an instance in which the filtered value associated with the proceeding, consecutive frames equals or exceeds the current value of the current frame.
13. A computer program product according to claim 12 wherein the computer-executable program code portions further comprise program code instructions for reducing at least one of the first and second counters in an instance in which the filtered value associated with the proceeding, consecutive frames equals or exceeds the current value of the current frame.
14. A computer program product according to claim 13 wherein the computer-executable program code portions further comprise program code instructions for determining that the preceding, consecutive frames are ascending or program code instructions for determining that the preceding, consecutive frames are descending, wherein the program code instructions for reducing at least one of the first and second counters comprise program code instructions for reducing, but not resetting, at least one of the first and second counters in an instance in which the preceding, consecutive frames are determined to be ascending or to be descending.
15. A computer program product according to claim 12 wherein the computer-executable program code portions further comprise program code instructions for determining a weight associated with the difference between the prior filtered value and the current value of the current frame, and wherein program code instructions for determining the filtered value of the current frame comprise program code instructions for determining the filtered value of the current frame based upon a combination of the plurality of weights and the current value of the current frame.