Glossary

This section provides meanings and definitions for terms that one may find in Prophesee documentations.

Generic terms

Term

Definition

Meaning

AER

Address-Event Representation

Transmission protocol for event-based data. An “event” is a data packet containing the pixel’s address in the array plus a payload, e.g. contrast detection polarity

AFK

Anti FlicKer

Technique allowing to remove flickering events (in SW or HW)

APS event

Active Pixel Sensor

Deprecated name for EM event

ATIS

Asynchronous Time-based Image Sensor

Name for Prophesee’s family of frame-free contrast-triggered pixel-individually auto-sampling image sensors with time-domain intensity encoding

Biases

Set of settings allowing to control Prophesee sensors (e.g. their sensitivity, bandwidth, etc)

CD event

Contrast Detection

Indicates an “event” triggered by temporal contrast (relative intensity change). CD events have a polarity, negative or positive (CD ON or CD OFF),

depending on if triggered by decreasing or increasing light intensity

Crazy Pixel

Pixel generating spontaneous background activity; data from crazy pixels can be removed with filtering algorithms (e.g. STC filter)

EM event

Exposure Measurement

Event-based grey-level data representation using time-domain encoding of the intensity information

EPS

Events Per Second

Readout Speed. For example, EPSMAX - Maximum throughput (Events per second, EPS) of the event readout system

ERC

Event Rate Control

Technique used to control the maximum event rate of a sensor

Event

Sensor-generated data packet containing the pixel’s address in the array, a payload (e.g. contrast detection polarity), and a timestamp

EVK

Evaluation Kit

Prophesee camera with the capability to visualize, record and process data on a PC

EVT

Event Type Definition

Prophesee Event-Based Processing Systems gather data from the sensor and encode these data in a proprietary event stream format.

This event format has been specified to strike a balance between compactness and robustness.

FOV

Field Of View

Area that can be seen by the camera with its optics at the given position

MIPI

Mobile Industry Processor Interface

Interface supported by some of Prophesee products and sensors

NCT

Nominal Contrast Threshold

Contrast at 10 lux with response probability higher than 0.5

ONBOARD

Prophesee Reference System (deprecated), an embedded solution that combines Prophesee sensor and computer vision products on a single board computer platform

Metavision Designer

Prophesee software allowing engineers to interconnect components very easily for fast prototyping of Event-Based Vision applications

Metavision HAL

Hardware Abstraction Layer

Prophesee software aimed at controlling Prophesee event-based cameras and acquiring data

Metavision Player

Prophesee Graphical User Interface allowing to visualize and record data from event-based sensors and also read already recorded data (e.g. datasets)

Metavision SDK

Prophesee C++ SDK allowing to process event-based data. High-performance algorithms are available via APIs, ready to go to production with Event-Based Vision applications

Polarity

Property of a CD event that can be negative or positive (CD ON or CD OFF) depending on if triggered by decreasing or increasing light

Prophesee Player

deprecated software

PSM

Particle Size Measurement

Application aimed at measuring size of particles

ROI

Region of Interest

Part of the sensor still active while other pixels are kept in reset, to focus on specific parts of the scene

TD event

Temporal Difference

Deprecated name for CD events

Timestamp

Time of event generation by Prophesee sensor, in microsecond precision

Trigger

Input or output signals (Trigger In or Out) allowing to control the sensor and synchronize data between several devices

VCEB

VisionCam Event-Based

Imago technologies’s Reference system using Prophesee sensor

XYT view

X-Y-Time view

3D representation of events data in X-Y-Time space

SW-specific terms

Term

Definition

Meaning

Application

Software tool aimed at solving specific needs (e.g. focusing, calibration, data conversion, etc); it is delivered as pre-compiled binaries and ready for execution

Asynchronous algorithm

Algorithm processing time slices of fixed duration and allowing to retrieve an outcome at a fixed refresh rate rather than for each processed buffer of events

Pipeline

Class aimed at simplifying the writing of algorithms; it processes data as a pipeline of processing units (stages) and controls their execution

Pipeline stage

Processing unit (stage) in a pipeline; each processing stage can have previous stages and next stages, thus forming a directed graph

ROS

Robot Operating System

Set of software libraries and tools that help to build robot applications

Sample

Code example aimed at demonstrating a concept as simple as possible, it serves as a tutorial and delivered as source code

STC filter

Spacial Temporal Contrast

Data filtering algorithm aimed to remove noisy data based on spatio-temporal consistency (presence of other events in space and time)

Synchronous algorithm

Algorithm directly processing each received buffer of events and generating an outcome for each processed buffer

Trail Filter

Data filtering algorithm aimed at filtering events at a pixel level where all events following the first event for the same pixel are discarded