Event-based down sampling

Patent metadata

Field	Value
Publication number	US-9883122-B2
Application number	US-201514853991-A
Country	US
Kind code	B2
Filing date	Sep 14, 2015
Priority date	Sep 16, 2014
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A method of event-based down sampling includes receiving multiple sensor events corresponding to addresses and time stamps. The method further includes spatially down sampling the addresses based on the time stamps and the addresses. The method may also include updating a pixel value for each of the multiple sensor events based on the down sampling.

First claim

What is claimed is:

1. A method of event-based down sampling, comprising:
receiving a plurality of sensor events, each sensor event of the plurality of sensor events corresponding to an address and a time stamp;
selecting a first sensor event from the plurality of sensor events;
determining that a second sensor event from the plurality of sensor events is received within a predetermined time of a time stamp corresponding to the first sensor event; and
spatially down sampling the first sensor event and the second sensor event based on the second sensor event being received within the predetermined time.

2. The method of claim 1 , in which spatially down sampling comprises mapping an original coordinate system to a down sampled coordinate system.

3. The method of claim 2 , in which spatially down sampling comprises dropping at least one least significant bit of the addresses.

4. The method of claim 1 , further comprising down sampling in time by computing a time stamp value as a function of time stamps within packets being down sampled.

5. The method of claim 1 , further comprising down sampling in time by selecting a specific sensor event corresponding with a specific time stamp when a plurality of sensor events with a common address have different time stamps, within a predetermined time span.

6. The method of claim 1 , further comprising:
determining whether the first sensor event and the second sensor event are spatially down sampled;
updating a pixel value corresponding to each of the plurality of sensor events when the first sensor event and the second sensor event are spatially down sampled; and
maintaining the pixel value corresponding to each of the plurality of sensor events when the first sensor event and the second sensor event are not spatially down sampled.

7. An apparatus for event-based down sampling, comprising:
means for receiving a plurality of sensor events, each sensor event of the plurality of sensor events corresponding to an address and a time stamp;
means for selecting a first sensor event from the plurality of sensor events;
means for determining that a second sensor event from the plurality of sensor events is received within a predetermined time of a time stamp corresponding to the first sensor event; and
means for spatially down sampling the first sensor event and the second sensor event based on the second sensor event being received within the predetermined time.

8. The apparatus of claim 7 , in which the means for spatially down sampling comprises means for mapping an original coordinate system to a down sampled coordinate system.

9. The apparatus of claim 8 , in which the means for spatially down sampling comprises means for dropping at least one least significant bit of the addresses.

10. The apparatus of claim 7 , further comprising means for down sampling in time by computing a time stamp value as a function of time stamps within packets being down sampled.

11. The apparatus of claim 7 , further comprising means for down sampling in time by selecting a specific sensor event corresponding with a specific time stamp when a plurality of sensor events with a common address have different time stamps, within a predetermined time span.

12. The apparatus of claim 7 , further comprising:
means for determining whether the first sensor event and the second sensor event are spatially down sampled;
means for updating a pixel value corresponding to each of the plurality of sensor events when the first sensor event and the second sensor event are spatially down sampled; and
means for maintaining the pixel value corresponding to each of the plurality of sensor events when the first sensor event and the second sensor event are not spatially down sampled.

13. An apparatus for event-based down sampling, comprising:
a memory unit; and
at least one processor coupled to the memory unit, the at least one processor being configured:
to receive a plurality of sensor events, each sensor event of the plurality of sensor events corresponding to an address and a time stamp;
to select a first sensor event from the plurality of sensor events;
to determine that a second sensor event from the plurality of sensor events is received within a predetermined time of a time stamp corresponding to the first sensor event; and
to spatially down sample the first sensor event and the second sensor event based on the second sensor event being received within the predetermined time.

14. The apparatus of claim 13 , in which the at least one processor is further configured to spatially down sample by mapping an original coordinate system to a down sampled coordinate system.

15. The apparatus of claim 14 , in which the at least one processor is further configured to spatially down sample by dropping at least one least significant bit of the addresses.

16. The apparatus of claim 13 , in which the at least one processor is further configured to down sample in time by computing a time stamp value as a function of time stamps within packets being down sampled.

17. The apparatus of claim 13 , in which the at least one processor is further configured to down sample in time by selecting a specific sensor event corresponding with a specific time stamp when a plurality of sensor events with a common address have different time stamps, within a predetermined time span.

18. The apparatus of claim 13 , in which the at least one processor is further configured:
to determine whether the first sensor event and the second sensor event are spatially down sampled;
to update a pixel value corresponding to each of the plurality of sensor events when the first sensor event and the second sensor event are spatially down sampled; and
to maintain the pixel value corresponding to each of the plurality of sensor events when the first sensor event and the second sensor event are not spatially down sampled.

19. A non-transitory computer-readable medium having program code recorded thereon, the program code for event-based down sampling being executed by a processor and comprising:
program code to receive a plurality of sensor events, each sensor event of the plurality of sensor events corresponding to an address and a time stamp;
program code to select a first sensor event from the plurality of sensor events;
program code to determine that a second sensor event from the plurality of sensor events is received within a predetermined time of a time stamp corresponding to the first sensor event; and
program code to spatially down sample the first sensor event and the second sensor event based on the second sensor event being received within the predetermined time.

20. The computer-readable medium of claim 19 , in which the program code to spatially down sample comprises program code to map an original coordinate system to a down sampled coordinate system.

21. The computer-readable medium of claim 20 , in which the program code to spatially down sample comprises program code to drop at least one least significant bit of the addresses.

22. The computer-readable medium of claim 19 , further comprising program code to down sample in time by computing a time stamp value as a function of time stamps within packets being down sampled.

23. The computer-readable medium of claim 19 , further comprising program code to down sample in time by selecting a specific sensor event corresponding with a specific time stamp when a plurality of sensor events with a common address have diff

Assignees

• Qualcomm Inc

Inventors

• Rangan Venkat
• Constable William Howard
• Wang Xin
• Rastogi Manu

Classifications

• G06V20/52 Primary

  Surveillance or monitoring of activities, e.g. for recognising suspicious objects (recognising microscopic objects G06V20/69) · CPC title

• H04N25/76

  Addressed sensors, e.g. MOS or CMOS sensors · CPC title

• G06N3/063

  using electronic means · CPC title

• G06F17/10

  Complex mathematical operations {(function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544)} · CPC title

• G06V30/2504

  Coarse or fine approaches, e.g. resolution of ambiguities or multiscale approaches · CPC title