Method and system for testing target sensing time of event camera

Abstract

The invention relates to the technical field of event camera index testing, in particular to a method and system for testing target sensing time of an event camera, and the method comprises the steps: firstly, employing a light source module with a target to irradiate an event camera to be tested; synchronously controlling the target and the to-be-tested event camera, enabling the to-be-tested event camera to insert a self-defined identifier in an output data stream, enabling the target to generate vibration, and causing the to-be-tested event camera to respond and output a target image; determining target generation time according to the output data stream and the custom identifier; and taking the target generation time as a reference, acquiring a projection image of the data stream along the time axis, and when a target image is acquired in the projection image, taking a difference value between the current moment and the target generation time as the target sensing time of the event camera to be detected. According to the invention, a synchronous triggering method is utilized to measure the target sensing time of the event camera, and an efficient, accurate and quantifiable test method is provided for the target sensing time of the event camera.

Description

Technical Field

[0001] The present invention belongs to the technical field of event camera indicator testing, and in particular relates to a testing method and system for event camera target perception time. Background Art

[0002] Event cameras use event-triggered detectors as their core imaging devices. With their special pixel structure, they can asynchronously respond to changes in light intensity in a scene. They have the advantages of instant response and instant perception and are now widely used in the field of machine vision. However, there is currently no specific test method to quantify the target perception time.

[0003] Traditional CMOS image sensors acquire target information through an "exposure" imaging system, so their target perception time can be equivalent to the exposure time. However, event cameras respond asynchronously to changes in light intensity in the scene, acquire target information through a "dynamic trigger, asynchronous response" imaging system, and output target information in the form of a spatiotemporal data stream, without the concept of exposure. Therefore, an accurate and quantifiable test method is needed to measure the target perception time of event cameras. Summary of the invention

[0004] In view of this, the present invention aims to provide a test method and system for the target perception time of an event camera, which measures the target perception time of an event camera by using a synchronous triggering method, thereby providing an accurate and quantifiable test method for the target perception time of an event camera.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows: A method for testing target perception time of an event camera, comprising: S1: Setting a target in the light source module; controlling the light source module to emit a light beam to the event camera to be tested; S2: Synchronously controlling the light source module and the event camera to be tested, so that the event camera to be tested inserts a custom identifier into the output data stream, and the light source module controls the target to vibrate, causing the event camera to respond and output a target image; S3: Determine the target generation time according to the data stream and the custom identifier in step S2; S4: Taking the target generation time determined in step S3 as a reference, obtain the projection image of the data stream along the time axis. When the target image generated in step S2 is obtained in the projection image, the difference between the current moment and the target generation time is the target perception time of the camera of the event to be tested.

[0006] Furthermore, in step S1: the light source module includes a light source, a collimator and a trigger motor; the target is set at the tail of the collimator, the light source illuminates the tail of the collimator, so that the collimator emits parallel light to the camera of the event to be measured; the trigger motor controls the target to vibrate.

[0007] Further, in step S2: when the event camera to be tested receives a control signal, the event camera to be tested inserts a custom identifier into the data stream; when the light source module receives the control signal, it controls the target to vibrate, so that the event camera to be tested responds to generate an output corresponding to the target image.

[0008] Further, in step S3: determine the time t where the custom identifier is located in the data stream, if there is no target image in the projection image of the data stream in the preset time period, record the time t as the target generation time, otherwise repeat steps S1 to S3.

[0009] A test system for target perception time of an event camera comprises: a light source module, which emits a light beam to the event camera to be tested; a target, which is arranged in the light source module and photographed by the event camera to be tested to obtain a corresponding target image; and a control module, which sends a synchronous control signal to the light source module and the event camera to be tested, and determines the target perception time of the event camera to be tested according to a data stream from the event camera to be tested.

[0010] Furthermore, the light source module includes a light source, a collimator and a trigger motor; the target is set at the tail of the collimator, the light source illuminates the tail of the collimator, so that the collimator emits parallel light to the event camera; the trigger motor receives a synchronous control signal and controls the target to vibrate.

[0011] Furthermore, the light source is a non-stroboscopic light source.

[0012] Furthermore, the control module sends a synchronization control signal to the light source module and the event camera to be tested; when the event camera to be tested receives the synchronization control signal, the imaging device event trigger detector in the event camera to be tested inserts a custom identifier into the data stream, and transmits the data stream with the custom identifier to the control module; when the light source module receives the synchronization control signal, it controls the target to vibrate, so that the event camera to be tested responds to generate an output corresponding to the target image.

[0013] Furthermore, in the control module, the time t at which the custom identifier is located is determined in the received data stream. If there is no target image in the projection image of the data stream within the preset time period, the time t is recorded as the target generation time. Taking the target generation time as a reference, the projection image of the data stream is obtained along the time axis. When the target image is obtained in the projection image, the difference between the current time and the target generation time is the target perception time of the camera for the event to be tested.

[0014] Compared with the prior art, the invention can achieve the following beneficial effects: (1) The present invention creates a test method and system for the target perception time of an event camera. A synchronous trigger method is used to insert an identifier into the output data of the event trigger detector of the event camera imaging device when the target vibration causes the event camera to respond, and the target generation time is confirmed in the output data. The test method is simple and can quickly and effectively complete the event camera target perception time measurement with high accuracy. (2) The present invention creates a method and system for testing target perception time of an event camera using a non-stroboscopic light source for testing, thereby avoiding interference caused by micro-vibration and light source flicker. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 A flow chart of a method for testing target perception time of an event camera according to an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a test system for event camera target perception time according to an embodiment of the present invention.

[0016] Description of reference numerals: 1. Light source module; 2. Target; 3. Control module; 4. Event camera to be measured; 5. Light source; 6. Collimator; 7. Trigger motor; 8. Optical platform. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0022] like Figure 1 As shown, the test method for event camera target perception time described in the embodiment of the present invention includes: S1: Set a target in the light source module; control the light source module to emit a light beam to the camera of the event to be measured.

[0023] In some embodiments, the light source module in step S1 includes a light source, a collimator and a trigger motor. The target is set at the tail of the collimator. The light source illuminates the tail of the collimator so that the collimator emits parallel light to the camera of the event to be measured; the trigger motor controls the target to vibrate.

[0024] S2: Synchronously control the light source module and the event camera to be tested, so that the event camera to be tested inserts a custom identifier into the output data stream, and the light source module controls the target to vibrate, causing the event camera to respond and output the target image.

[0025] In some embodiments, when the camera of the event to be tested receives a control signal, the camera of the event to be tested inserts a custom identifier into the data stream; when the light source module receives the control signal, the target is controlled to vibrate, so that the camera of the event to be tested responds to generate an output corresponding to the target image. It should be noted that the camera of the event to be tested inserts the custom identifier into the data stream and triggers the motor to control the target vibration at the same time, thereby achieving synchronous triggering.

[0026] S3: Determine the target generation time according to the data stream and the custom identifier in step S2.

[0027] In some embodiments, in step S3: determine the time t where the custom identifier is located in the data stream; if there is no target image in the projection image of the data stream within the preset time period, record the time t as the target generation time; otherwise repeat steps S1 to S3; the preset time period can be adaptively adjusted according to actual conditions. In a certain embodiment, the time period [t-1, t] between the time t and the previous millisecond t-1 is set as the preset time period.

[0028] S4: Taking the target generation time determined in step S3 as a reference, obtain the projection image of the data stream along the time axis. When the target image generated in step S2 is obtained in the projection image, the difference between the current moment and the target generation time is the target perception time of the camera of the event to be tested.

[0029] In a specific implementation, taking the target generation time t as a reference and taking milliseconds as a unit, the projection images of the data stream on the time axis in the time periods [t, t+1], [t, t+2], ..., [t, t+∆t] are sequentially acquired until the target image is acquired in the projection image. At this time, the difference ∆t between the current time t+∆t and the target generation time t is the target perception time.

[0030] According to the test method for event camera target perception time provided by the embodiment of the present invention, the present invention correspondingly provides a test system for event camera target perception time, such as Figure 2 As shown, it includes a light source module 1, a target 2 and a control module 3. The light source module 1 emits a light beam to the event camera 4 to be tested; the target 2 is installed in the light source module 1 and is photographed by the event camera 4 to be tested to obtain a corresponding target image; the control module 3 sends a synchronization control signal to the light source module 1 and the event camera 4 to be tested, and determines the target perception time of the event camera to be tested according to the data stream from the event camera 4 to be tested.

[0031] In some embodiments, the light source module 1 includes a light source 5, a collimator 6 and a trigger motor 7. The target 2 is fixed at the tail of the collimator 6. The light source 5 illuminates the tail of the collimator 6, so that the collimator 6 emits parallel light to the event camera 4. The trigger motor 7 receives the synchronization control signal and controls the target 2 to vibrate. In a specific embodiment, the light source module 1, the control module 3 and the event camera 4 to be tested are placed on an optical platform 8. At the same time, the light source 5 preferably uses a non-stroboscopic light source to avoid interference caused by micro-vibration and light source flickering. In addition, in order to simplify the test system, the trigger motor 7 preferably uses a patch type micro motor, which is attached to the target 2 behind the collimator 6. When the patch type micro motor receives the synchronization control signal from the control module 3, it controls the target 2 to vibrate. Finally, the control module 3 preferably sends a periodic synchronization control signal to the light source module 1 and the event camera 4 to be tested. The periodic synchronization control signal can collect multiple data in one test to increase the number of valid data.

[0032] The control module 3 sends a synchronization control signal to the light source module 1 and the event camera 4. When the event camera 4 receives the synchronization control signal, the imaging device event trigger detector in the event camera 4 inserts a custom identifier into the data stream, and transmits the data stream with the custom identifier to the control module 3; when the trigger motor 7 in the light source module 1 receives the synchronization control signal, it controls the target 8 to vibrate, so that the event camera 4 responds to generate an output corresponding to the target image.

[0033] In the control module 3, the time t at which the custom identifier is located is determined in the received data stream. If there is no target image in the projection image of the data stream in the preset time period, the time t is recorded as the target generation time. Taking the target generation time as the reference, the projection image of the data stream is obtained along the time axis. When the target image is obtained in the projection image, the difference between the current time and the target generation time is the target perception time of the camera of the event to be tested. The preset time period can be adaptively adjusted according to the actual situation. In a certain embodiment, the time period [t-1, t] between the time t and the previous second t-1 is set as the preset time period.

[0034] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0035] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A test method for event camera target perception time, characterized in that: include: S1: Setting a target in a light source module; controlling the light source module to emit a light beam to a camera of an event to be measured; S2: synchronously controlling the light source module and the event camera to be tested, so that the event camera to be tested inserts a custom identifier into the output data stream, and the light source module controls the target to vibrate, causing the event camera to respond and output a target image; S3: Determine the target generation time according to the data stream and the custom identifier in step S2; S4: Taking the target generation time determined in step S3 as a reference, a projection image of the data stream is obtained along the time axis. When the target image generated in step S2 is obtained in the projection image, the difference between the current moment and the target generation time is the target perception time of the camera for the event to be tested.

2. The method for testing target perception time of event cameras according to claim 1, characterized in that: In step S1: the light source module includes a light source, a collimator and a trigger motor; the target is arranged at the tail of the collimator, and the light source illuminates the tail of the collimator, so that the collimator emits parallel light to the event camera to be measured; The trigger motor controls the target to vibrate.

3. The method for testing target perception time of event cameras according to claim 1, characterized in that: In step S2: When the event camera to be tested receives a control signal, the event camera to be tested inserts the custom identifier into the data stream; when the light source module receives a control signal, it controls the target to vibrate so that the event camera to be tested responds and generates an output corresponding to the target image.

4. The method for testing target perception time of event cameras according to claim 1, characterized in that: In step S3: Determine the time t at which the custom identifier is located in the data stream. If there is no target image in the projection image of the data stream within a preset time period, record the time t as the target generation time. Otherwise, repeat steps S1 to S3.

5. A test system for event camera target perception time, characterized in that: include: A light source module emits a light beam to a camera for an event to be measured; A target is arranged in the light source module and is photographed by the event camera to obtain a corresponding target image; The control module sends a synchronization control signal to the light source module and the camera for the event to be measured, and determines the target perception time of the camera for the event to be measured according to the data stream from the camera for the event to be measured.

6. The test system for event camera target perception time according to claim 5, characterized in that: The light source module includes a light source, a collimator and a trigger motor; the target is arranged at the tail of the collimator, the light source illuminates the tail of the collimator, so that the collimator emits parallel light to the camera of the event to be measured; the trigger motor receives the synchronization control signal and controls the target to vibrate.

7. The test system for event camera target perception time according to claim 6, characterized in that: The light source is a non-stroboscopic light source.

8. The test system for event camera target perception time according to claim 5, characterized in that: The control module sends a synchronization control signal to the light source module and the event camera to be tested; When the event camera to be tested receives the synchronization control signal, the imaging device event trigger detector in the event camera to be tested inserts a custom identifier into the data stream, and transmits the data stream with the custom identifier to the control module; When the light source module receives the synchronization control signal, it controls the target to vibrate, so that the camera of the event to be detected responds to generate and output a corresponding target image.

9. The test system for event camera target perception time according to claim 8, characterized in that: In the control module, Determine the time t at which the custom identifier is located in the received data stream, and if there is no target image in the projection image of the data stream within the preset time period, record the time t as the target generation time; Taking the target generation time as a reference, a projection image of the data stream is obtained along the time axis. When the target image is obtained in the projection image, the difference between the current moment and the target generation time is the target perception time of the camera for the event to be tested.

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