Event filtering method for operating an event-based image sensor

    公开(公告)号:US11689824B2

    公开(公告)日:2023-06-27

    申请号:US17906063

    申请日:2021-03-10

    申请人: PROPHESEE

    摘要: Embodiments of the present disclosure include an event-based image sensor and an event filtering method for use with an event-based image sensor. The event-based image sensor comprises a plurality of pixel circuits forming a pixel array, each pixel circuit comprising a photoreceptor circuit configured to generate a photoreceptor signal derived from a photocurrent generated by a light impinging on a light-sensitive element of the photoreceptor circuit, and a detector configured to detect a change in the photoreceptor signal and to generate an event in response to the detected change in the photoreceptor signal. The event-based image sensor further includes a processing chain and an event filter that is configured to receive the generated event and to accept the received event based on a plurality of conditions. The plurality of conditions include a condition that the received event is part of a previously unaccepted event trail, the event trail comprising a plurality of successive events having a same polarity and separated by time intervals each shorter than a time threshold.

    IMAGE SENSOR WITH A PLURALITY OF SUPER-PIXELS

    公开(公告)号:US20220264050A1

    公开(公告)日:2022-08-18

    申请号:US17662412

    申请日:2022-05-06

    申请人: Prophesee SA

    摘要: The present disclosure generally relates to image sensors and methods for image sensing. More specifically, and without limitation, this disclosure relates to systems and methods for providing super-pixels, and implementing and using image sensors with super-pixels. In one implementation, an image sensor includes a plurality of super-pixels. Each super-pixel may include a first photosensitive element; a detector electrically connected to the first photosensitive element and configured to generate a trigger signal when an analog signal proportional to brightness of light impinging on the first photosensitive element matches a condition; a second photosensitive element; an exposure measurement circuit electrically connected to the second photosensitive element and configured to convert an analog signal proportional to brightness of light impinging on the second photosensitive element to a digital signal; and a logic circuit electrically connected to the detector and the exposure measurement circuit and configured to enable the exposure measurement circuit in response to the trigger signal and to disable the exposure measurement circuit when the digital signal is read out from the exposure measurement circuit.

    METHOD FOR AUTOMATICALLY ADAPTING A PATTERN PROJECTION RATE IN AN ACTIVE PERCEPTION SYSTEM

    公开(公告)号:US20220166944A1

    公开(公告)日:2022-05-26

    申请号:US17534884

    申请日:2021-11-24

    申请人: Prophesee

    IPC分类号: H04N5/353 H04N5/232 H04N5/225

    摘要: A method is generally provided for adjusting a pattern projection rate in an active perception system, comprising the steps of observing a scene with an event-based sensor array; projecting a current light pattern of a sequence of light patterns on the scene for a given interval of time; retrieving events generated by the event-based sensor array in response to the projection of the current light pattern; monitoring a property of the event retrieval progress; and dynamically controlling the projection of the light pattern based on the property.

    Event-based image sensor and operating method thereof

    公开(公告)号:US11317045B2

    公开(公告)日:2022-04-26

    申请号:US16771665

    申请日:2018-12-11

    申请人: PROPHESEE

    IPC分类号: H04N5/3745 H04N5/376

    摘要: An event-based image sensor is provided that includes a plurality of pixel circuits. Each pixel circuit includes a photoreceptor circuit with a light-sensitive element configured for delivering at an output a photoreceptor current, an analog bus, and a bank of current memory cells connected to the analog bus. An output of the photoreceptor circuit is selectively connected to the analog bus. Each current memory cell is adapted to store an electric current flowing in the analog bus and to deliver an electric current stored within the current memory cell. Each pixel circuit may further include a current comparator including a current sign detector connected to the analog bus and configured for comparing a value of a compared electric current resulting from a difference between the photoreceptor current and a previous photoreceptor current stored in a current memory cell. At least one storage cell may also be provided that has a state conditioned by the output of the current sign detector.

    METHOD OF PROCESSING INFORMATION FROM AN EVENT-BASED SENSOR

    公开(公告)号:US20220101640A1

    公开(公告)日:2022-03-31

    申请号:US17427033

    申请日:2020-01-29

    申请人: PROPHESEE

    发明人: Xavier LAGORCE

    摘要: An event-based sensor has an array of pixels facing a scene. The information to be processed includes events originating from the pixels depending on variations of incident light from the scene. A method includes storing a data structure for a set of pixels of the array, the data structure including, for each pixel of the set, event data associated with a most recent event originating from the pixel. Upon receiving a current event from a first pixel of the array, the method includes retrieving any event data included in the data structure for a group of pixels including the first pixel and a plurality of second pixels adjacent to the first pixel in the array. The current event is labelled based on at least one connectivity criterion between the current event and the most recent event originating from a pixel of the group.

    Digital event encoding for operating an event-based image sensor

    公开(公告)号:US12063444B1

    公开(公告)日:2024-08-13

    申请号:US18272330

    申请日:2022-01-13

    申请人: PROPHESEE

    CPC分类号: H04N25/707 H04N25/77

    摘要: A method is provided for operating an event-based image sensor comprising a plurality of pixel circuits arranged to form a pixel array, each pixel being arranged at a location defined by an address defined by pixel coordinates in the array, wherein each pixel circuit is configured to generate an event, such that each time a light intensity change is detected, an event is characterized by a polarity reflecting a direction of the change. The method comprises performing a line readout of groups of adjacent pixels of a line of pixels, wherein the line readout comprises generating, for each group, at least one packet expressing occurrences of events of a same polarity in said group, each packet being characterized by a polarity and a group address. The method further comprises sending the packets to a processing pipeline where the packets are successively processed, involving a memory access based on the group address, wherein two packets sharing the same group address have different polarities and are consecutively processed.

    METHOD OF PROCESSING A SERIES OF EVENTS RECEIVED ASYNCHRONOUSLY FROM AN ARRAY OF PIXELS OF AN EVENT-BASED LIGHT SENSOR

    公开(公告)号:US20220100658A1

    公开(公告)日:2022-03-31

    申请号:US17430141

    申请日:2020-02-10

    申请人: PROPHESEE

    IPC分类号: G06F12/0815 G06F12/0895

    摘要: The method processes a series of events received asynchronously from an array of pixels of an event-based light sensor. Each event of the series comprises an address of a pixel of the array from which the event is received, and an attribute value depending on incident light sensed by that pixel. The method comprises: storing a data structure in a first memory, the data structure including event data for at least some of the pixels of the array, the event data for a pixel being related to at least one event most recently received from said pixel; during a timeslot, building, in a second memory having a faster access than the first memory, a map for the pixels of the array as the events of the series are received, the map including an information element for each pixel of the array, the information element having one of a plurality of values including a nil value indicating an absence of event during the timeslot; and updating the data structure after the timeslot using the map.

    METHOD OF TRACKING OBJECTS IN A SCENE

    公开(公告)号:US20220036110A1

    公开(公告)日:2022-02-03

    申请号:US17413347

    申请日:2019-12-13

    申请人: PROPHESEE

    IPC分类号: G06K9/32 G06K9/00

    摘要: The present invention relates to a method of tracking objects in a scene observed by an event-based sensor that produces events asynchronously from a matrix of sensing elements, wherein, from each sensing element of the matrix, respective events are produced as a function of variations of light incident on the sensing element, the method comprising: detecting, by a first process, an object in the scene from asynchronous events produced by the event-based sensor; and determining, by a second process, a track associated to the detected object from asynchronous events produced by the event-based sensor; wherein the first process has a time resolution lower than the second process.