US 11,749,004 B2
Event detector and method of generating textural image based on event count decay factor and net polarity
Amr Elrasad, Galway (IE); Cian Ryan, Galway (IE); Richard Blythman, Galway (IE); Joe Lemley, Galway (IE); and Brian O'Sullivan, Galway (IE)
Assigned to FotoNation Limited
Filed by FotoNation Limited, Galway (IE)
Filed on Feb. 24, 2022, as Appl. No. 17/680,095.
Application 17/680,095 is a continuation of application No. 17/037,420, filed on Sep. 29, 2020, granted, now 11,270,137.
Application 17/037,420 is a continuation in part of application No. 16/941,799, filed on Jul. 29, 2020, granted, now 11,301,702.
Application 16/941,799 is a continuation in part of application No. 16/904,122, filed on Jun. 17, 2020, granted, now 11,164,019, issued on Nov. 2, 2021.
Prior Publication US 2022/0254171 A1, Aug. 11, 2022
Int. Cl. G06V 20/59 (2022.01); G06T 7/246 (2017.01); G06V 10/25 (2022.01); G06V 20/52 (2022.01); G06T 11/00 (2006.01); H04N 7/18 (2006.01)
CPC G06V 20/597 (2022.01) [G06T 7/246 (2017.01); G06T 11/001 (2013.01); G06V 10/25 (2022.01); G06V 20/52 (2022.01); H04N 7/18 (2013.01); G06T 2207/30268 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method comprising:
accumulating event information from a plurality of events occurring during successive event cycles across a field of view of an event camera, each event indicating an x,y location within said field of view, a polarity for a change of detected light intensity incident at said x,y location and an event cycle at which said event occurred;
responsive to a selected event cycle, analyzing event information for one or more preceding event cycles to identify a region of interest bounding an eye region; and
responsive to a threshold event criterion, generating a textural image for the region of interest from event information accumulated from within the region of interest by:
obtaining a count (pc) of events occurring at each pixel location of an output image in a time window preceding the threshold event criterion; determining a potential absence of a blink within said eye region based at least in part on the count (pc) of events before producing the textural image;
generating a decay factor (ph) for each pixel location as a function of said count; and
producing said textural image based on the decay factor (ph) and the count (pc).