Methods and devices to identify focal objects

Patent metadata

Field	Value
Publication number	US-11528407-B2
Application number	US-202017122667-A
Country	US
Kind code	B2
Filing date	Dec 15, 2020
Priority date	Dec 15, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A method includes dividing a field of view into a plurality of zones and sampling the field of view to generate a photon count for each zone of the plurality of zones, identifying a focal sector of the field of view and analyzing each zone to select a final focal object from a first prospective focal object and a second prospective focal object.

First claim

What is claimed is:

1. A method to identify a focal object in a field of view, the method comprising:
dividing a field of view into a plurality of zones;
identifying a focal sector occupying a subset of the plurality of zones;
analyzing each zone of the plurality of zones within the focal sector to identify a first prospective focal object and to identify a second prospective focal object;
determining a size of the first prospective focal object in the field of view and determining a size of the second prospective focal object in the field of view;
selecting a final focal object from the first prospective focal object and the second prospective focal object by comparing the size of the first prospective focal object with the size of the second prospective focal object; and
focusing a lens of a camera depending on the final focal object.

2. The method of claim 1 , wherein the focal sector is identified based on user input.

3. The method of claim 1 , wherein the focal sector is identified based on a predetermined parameter.

4. The method of claim 1 , wherein the size of the first prospective focal object is determined by analyzing each zone of the plurality of zones and counting a first number of zones where the first prospective focal object is present and wherein the size of the second prospective focal object is determined by analyzing each zone of the plurality of zones and counting a second number of zones where the second prospective focal object is present.

5. The method of claim 4 , further comprising sampling the field of view with a Time of Flight system to generate a photon count for each zone of the plurality of zones and wherein the final focal object is located at a final-focal-object distance from the Time of Flight system.

6. The method of claim 5 , wherein counting the first number of zones comprises analyzing the photon count for each zone of the plurality of zones to identify each zone of the plurality of zones that captures an object within a threshold distance of the first prospective focal object and wherein counting the second number of zones comprises analyzing the photon count for each zone of the plurality of zones to identify each zone of the plurality of zones that captures an object within the threshold distance of the second prospective focal object.

7. The method of claim 5 , further comprising averaging the final-focal-object distance with a distance of each object within a threshold distance of the final focal object in each zone of the plurality of zones where the final focal object is present.

8. The method of claim 5 , further wherein, the field of view comprises a field of view of the Time of Flight System.

9. The method of claim 5 , further comprising determining that the final-focal-object distance is equal to a last distance previously outputted by the Time of Flight system and outputting the final-focal-object distance from the Time of Flight system to focus the lens of the camera.

10. The method of claim 5 , further comprising:
determining that that the final-focal-object distance does not equal a last distance previously outputted by the Time of Flight system;
determining that the final-focal-object distance is equal to a plurality of previously-identified final-focal-object distances; and
outputting, by the Time of Flight system, the final-focal-object distance to focus the lens of the camera.

11. The method of claim 5 , further comprising:
determining that that the final-focal-object distance does not equal a last distance previously outputted by the Time of Flight system;
determining that the final-focal-object distance does not equal to a plurality of previously-identified final-focal-object distances; and
outputting, by the Time of Flight system, the last distance previously outputted by the Time of Flight system to focus the lens of the camera.

12. The method of claim 5 , further comprising:
determining that a last distance previously outputted by the Time of Flight system is not equal to a distance of the first prospective focal object;
determining that the last distance previously outputted by the Time of Flight system is not equal to a distance of the second prospective focal object;
determining that the final-focal-object distance does not equal a plurality of previously-identified final-focal-object distances; and
outputting, by the Time of Flight system the last distance previously outputted by the Time of Flight system to focus the lens of the camera.

13. The method of claim 5 , further comprising:
determining that a last distance previously outputted by the Time of Flight system is not equal to a distance of the first prospective focal object;
determining that the last distance previously outputted by the Time of Flight system is not equal to a distance of the second prospective focal object;
determining that the final-focal-object distance is equal to a plurality of previously-identified final-focal-object distances; and
outputting, by the Time of Flight system, the final-focal-object distance to focus the lens of the camera.

14. The method of claim 5 , further comprising analyzing each zone of the plurality of zones within the focal sector to identify a third prospective focal object;
determining a size of the third prospective focal object in the field of view; and
wherein the size of the third prospective focal object is also compared with the size of the first prospective focal object and the second prospective focal object to select the final focal object from the first prospective focal object, the second prospective focal object, and the third prospective focal object.

15. A system comprising:
a Time of Flight system configured to detect a photon count for each zone of a plurality of zones of a field of view;
a processor in communication with the Time of Flight system and a memory comprising an instruction set to be executed in the processor, the instruction set when executed causing the processor to:
identify a focal sector occupying a subset of the plurality of zones,
analyze each zone of the plurality of zones within the focal sector to identify a first prospective focal object and to identify a second prospective focal object,
determine a size of the first prospective focal object and determine a size of the second prospective focal object, and
select a final focal object from the first prospective focal object and the second prospective focal object by comparing the size of the first prospective focal object with the size of the second prospective focal object, the final focal object being located at a final-focal-object distance from the Time of Flight system; and

a lens focus system configured to focus a lens of a camera depending on the final focal object.

16. The system of claim 15 , wherein the Time of Flight system comprises:
an optical source configured to emit light into an environment; and
an optical receiver comprising a plurality of light-sensitive pixels to detect photons being reflected from the environment, the plurality of light-sensitive pixels arranged in a plurality of sections corresponding to the plurality of zones.

17. The system of claim 16 , wherein the Time of Flight system comprises the processor and wherein the processor receives the photon count for each zone of the plurality of zones from the optical receiver.

18. The system of claim 16 , wherein the optical receiver comprises an optical-receiver lens to direct photons to the plurality of sections.

19. A method to identify a focal object in a field of

Assignees

• St Microelectronics Inc
• St Microelectronics Sa
• St Microelectronics Res & Dev Ltd

Inventors

• Winterton Darin K
• Baxter Donald
• Hodgson Andrew
• Lunn Gordon
• Pothier Olivier
• Vadlamudi-Reddy Kalyan-Kumar

Classifications

• H04N23/61

  based on recognised objects · CPC title

• H04N23/62

  Control of parameters via user interfaces · CPC title

• H04N23/671

  in combination with active ranging signals, e.g. using light or sound signals emitted toward objects · CPC title

• G06V10/14 Primary

  Optical characteristics of the device performing the acquisition or on the illumination arrangements · CPC title

• H04N23/675 Primary

  comprising setting of focusing regions · CPC title