Frame manipulation to reduce rolling shutter artifacts
View Patent ↗An image sensor of a camera system captures an image over an image capture interval of time, and waits a blanking interval of time before capturing an additional image. The captured image is provided to a frame controller, and is buffered until an image signal processor accesses the captured image. The image signal processor processes the accessed image over an image processing interval of time, producing a processed image. The image processing interval of time is selected to be greater than the image capture interval of time, but less than the sum of the image capture interval of time and the blanking interval of time. By reducing the image capture interval of time but maintaining an image processing interval of time, rolling shutter artifacts are beneficially reduced without increasing the processing resources or power required by the image signal processor to process the image.
1. A camera system, comprising:
an image sensor configured to:
capture light during a frame capture interval to produce frame data, wherein the captured light comprises light incident upon the image sensor during the entire frame capture interval, and wherein the frame data is representative of the captured light; and
wait for a blanking interval of time that comprises an entire time period after the frame capture interval and a beginning of a subsequent frame capture interval, wherein no light is captured during the blanking interval;
a buffer memory for buffering the frame data; and
a hardware image signal processor that processes the buffered frame data during a frame processing interval to produce processed frame data, wherein the frame processing interval begins after the end of the frame capture interval and ends before the end of the subsequent frame capture interval, and wherein the length of the frame processing interval is longer than both the length of the blanking interval and the length of the frame capture interval.
2. The camera system of claim 1 , configured to select one or more of the frame capture interval, the blanking interval, and the frame processing interval.
3. The camera system of claim 1 , wherein the frame capture interval is selected based on a pre-determined time interval associated with reduced rolling shutter artifacts.
4. The camera system of claim 1 , wherein the frame capture interval is shorter than the blanking interval by a factor of 2 or more.
5. The camera system of claim 1 , wherein the frame capture interval is consistent with a first frame rate, wherein the frame processing interval is consistent with a second frame rate, and wherein the first frame rate is greater than the second frame rate.
6. The camera system of claim 1 , configured to set a flag after the buffering of the frame data, and wherein the image signal processor is configured to access the buffered frame data in response to the flag being set.
7. The camera system of claim 1 , wherein processing frame data comprises formatting the frame data into a displayable file format.
8. A method of capturing images, comprising:
capturing, by an image sensor, light during a frame capture interval to produce frame data, wherein the captured light comprises light incident upon the image sensor during the entire frame capture interval, and wherein the frame data is representative of the captured light;
buffering, by a memory, the frame data;
waiting, by the image sensor, for a blanking interval of time that comprises an entire time period after the frame capture interval and a beginning of a subsequent frame capture interval, wherein no light is captured during the blanking interval; and
processing, by an image signal processor, the buffered frame data during a frame processing interval to produce processed frame data, wherein the frame processing interval begins after the end of the frame capture interval and ends before the end of the subsequent frame capture interval;
wherein the length of the frame processing interval is longer than both the length of the blanking interval and the length of the frame capture interval.
9. The method of claim 8 , further comprising selecting, by a frame controller, one or more of the frame capture interval, the blanking interval, and the frame processing interval.
10. The method of claim 8 , wherein the frame capture interval is selected based on a pre-determined time interval associated with reduced rolling shutter artifacts.
11. The method of claim 8 , wherein the frame capture interval is shorter than the blanking interval by a factor of 2 or more.
12. The method of claim 8 , wherein the frame capture interval is consistent with a first frame rate, wherein the frame processing interval is consistent with a second frame rate, and wherein the first frame rate is greater than the second frame rate.
13. The method of claim 8 , further comprising setting a flag after buffering the frame data, and accessing, by the image signal processor, the buffered frame data in response to the flag being set.
14. The method of claim 8 , wherein processing frame data comprises formatting the frame data into a displayable file format.
15. A non-transitory computer-readable storage medium comprising computer-executable instructions for method of capturing images, the instructions configured to, when executed, perform steps comprising:
capturing, by an image sensor, light during a frame capture interval to produce frame data, wherein the captured light comprises light incident upon the image sensor during the entire frame capture interval, and wherein the frame data is representative of the captured light;
buffering, by a memory, the frame data;
waiting, by the image sensor, for a blanking interval of time that comprises an entire time period after the frame capture interval and a beginning of a subsequent frame capture interval, wherein no light is captured during the blanking interval; and
processing, by an image signal processor, the buffered frame data during a frame processing interval to produce processed frame data, wherein the frame processing interval begins after the end of the frame capture interval and ends before the end of the subsequent frame capture interval;
wherein the length of the frame processing interval is longer than both the length of the blanking interval and the length of the frame capture interval.
16. The computer-readable storage medium of claim 15 , wherein the instructions are configured to, when executed, perform further steps comprising, selecting, by a frame controller, one or more of the frame capture interval, the blanking interval, and the frame processing interval.
17. The computer-readable storage medium of claim 15 , wherein the frame capture interval is selected based on a pre-determined time interval associated with reduced rolling shutter artifacts.
18. The computer-readable storage medium of claim 15 , wherein the frame capture interval is shorter than the blanking interval by a factor of 2 or more.
19. The computer-readable storage medium of claim 15 , wherein the frame capture interval is consistent with a first frame rate, wherein the frame processing interval is consistent with a second frame rate, and wherein the first frame rate is greater than the second frame rate.
20. The computer-readable storage medium of claim 15 , wherein the instructions are configured to, when executed, perform further steps comprising:
setting a flag after buffering the frame data, and wherein the image signal processor is configured to access the buffered frame data in response to the flag being set.
21. The computer-readable storage medium of claim 15 , wherein processing frame data comprises formatting the frame data into a displayable file format.