Adaptive image sensor systems and methods
View Patent ↗An imaging device may include a primary imaging sensor and a secondary imaging sensor. The secondary imaging sensor may monitor a scene being imaged by the imaging device for trigger criteria such as sudden movement, changes in the intensity of ambient light, and the presence of a particular object or person. Upon detection of relevant trigger criteria, the imaging device may activate the primary imaging sensor and capture one or more images of the scene with the primary imaging sensor. Operational parameters of the primary imaging sensor including framerate and exposure settings may be based on data from the secondary imaging sensor. The secondary imaging sensor may have a lower power consumption than the primary imaging sensor such that monitoring the scene with the secondary imaging sensor and only activating the primary imaging sensor upon detection of the relevant trigger criteria enables an efficient and adaptive imaging system.
1. A method of operating an electronic device having first and second imaging sensors, wherein the first imaging sensor has a higher framerate than the second imaging sensor, the method comprising:
operating the first imaging sensor in an active mode in which the first imaging sensor captures video of a scene;
with the first imaging sensor, monitoring the scene for a predefined stop criterion;
with the first imaging sensor, detecting the predefined stop criterion in the scene;
with control circuitry in the electronic device and based upon the detection of the predefined stop criterion in the scene, switching the first imaging sensor into a power-conserving standby mode;
while the first imaging sensor is in the power-conserving standby mode, monitoring the scene for a predefined trigger criterion with the second imaging sensor;
with the second imaging sensor, detecting the predefined trigger criterion in the scene; and
with the control circuitry in the electronic device and based upon the detection of the predefined trigger criterion in the scene with the second imaging sensor, switching the first imaging sensor into the active mode in which the first imaging sensor captures video of a scene.
2. The method defined in claim 1 wherein the predefined trigger criterion comprises movement that is greater than a given displacement.
3. The method defined in claim 1 wherein the predefined trigger criterion comprises movement that is greater than a given displacement and that is located in a predefined subset of the scene.
4. The method defined in claim 1 wherein the predefined trigger criterion comprises movement that is greater than a given velocity.
5. The method defined in claim 1 wherein the predefined trigger criterion comprises detection of a person in the scene.
6. The method defined in claim 1 wherein the predefined trigger criterion comprises identification of a person in the scene.
7. The method defined in claim 1 wherein the predefined trigger criterion comprises identification of a given person's face in the scene.
8. The method defined in claim 1 wherein the predefined stop criterion comprises the absence of the predefined trigger criterion.
9. A method of operating an electronic device having first and second imaging sensors, the method comprising:
operating the first imaging sensor in an active mode in which the first imaging sensor captures video of a scene;
analyzing the captured video of the scene, wherein analyzing the captured video comprises detecting a predefined trigger criterion and detecting ambient light; and
in response to detecting the predefined trigger criterion with the first imaging sensor, activating the second imaging sensor in the electronic device and capturing video, wherein activating the second imaging sensor and capturing video comprises utilizing information obtained from analyzing the captured video from the first imaging sensor to adjust operational parameters of the second imaging sensor, and wherein the information obtained from the analysis of the captured video comprises information describing the speed of at least one object in the scene.
10. The method defined in claim 9 wherein the information describing the speed of at least one object in the scene comprises information describing the speed of a fastest moving object in the scene.
11. The method defined in claim 9 wherein the operational parameters that are adjusted comprise a framerate of the second imaging sensor.
12. The method defined in claim 9 wherein the operational parameters that are adjusted comprise exposure settings, white-balance settings, and focus settings.
13. A method, comprising:
with at least one imaging sensor in an electronic device, imaging a scene at a first framerate;
with the at least one imaging sensor, detecting a change in the scene; and
after detecting the change in the scene, adjusting the framerate of the at least one imaging sensor to a second framerate based upon the detected change in the scene, wherein imaging the scene at the first framerate with the at least one imaging sensor comprises imaging the scene at the first framerate with a primary imaging sensor, wherein detecting the change in the scene with the at least one imaging sensor comprises detecting the change in the scene with a secondary imaging sensor, and wherein adjusting the framerate of the at least one imaging sensor to the second framerate based upon the detected change in the scene comprises adjusting the framerate of the primary imaging sensor to the second framerate based upon the detected change in the scene.
14. The method defined in claim 13 further comprising:
with the secondary imaging sensor, detecting a series of changes in the scene; and
after each of the changes in the series of changes in the scene, adjusting the framerate of the primary imaging sensor based on that respective change.
15. The method defined in claim 14 wherein detecting the change in the scene comprises detecting movement in a selected region of the scene.
16. The method defined in claim 14 wherein detecting the change in the scene comprises detecting an object moving with a velocity greater than a threshold velocity, wherein adjusting the framerate of the primary imaging sensor to the second framerate comprises increasing the framerate of the primary imaging sensor such that the moving object is imaged substantially without motion blur.
17. The method defined in claim 16 further comprising:
with the secondary imaging sensor, detecting that all objects in the scene are moving with a velocity less than the threshold velocity; and
after detecting that all objects in the scene are moving with a velocity less than the threshold velocity, adjusting the framerate of the primary imaging sensor back to the first framerate.