Test method and system for target perception time of event camera

Abstract

The present invention relates to the technical field of event camera index testing, and particularly to a testing method and system for the target perception time of an event camera. First, a light source module with a target is used to irradiate the event camera to be tested; the target and the event camera to be tested are synchronously controlled, so that the event camera to be tested inserts a custom identifier into the output data stream, and the target generates vibrations, causing the event camera to be tested to respond and output a target image; the target generation time is determined according to the output data stream and the custom identifier; taking the target generation time as a reference, a projection image of the data stream is obtained along the time axis, and 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 event camera to be tested. The present invention uses a synchronous triggering method to measure the target perception time of an event camera, providing an efficient, accurate and quantifiable testing method for the target perception time of an event camera.

Description

Technical Field

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

[0002] An event camera uses an event-triggered detector as the core imaging device. With its special pixel structure, it can asynchronously respond to the changes in light intensity in the scene, having the advantages of instant response and instantaneous perception, and has now been widely used in the field of machine vision. However, there is currently no specific testing method to quantitatively test its target perception time.

[0003] Traditional CMOS image sensors obtain target information with an "exposure" imaging system, so their target perception time can be equivalent to the exposure time. However, event cameras asynchronously respond to the changes in light intensity in the scene, obtain target information with an "event-triggered, asynchronous response" imaging system, and output target information in the form of spatio-temporal data streams, without the concept of exposure. Therefore, an accurate and quantifiable testing 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 testing method and system for the target perception time of an event camera, using a synchronous triggering method to measure the target perception time of the event camera, and providing an accurate and quantifiable testing method for the target perception time of the event camera.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] A testing method for the target perception time of an event camera includes:

[0007] S1: Set a target in the light source module; control the light source module to emit a light beam towards the event camera to be tested;

[0008] 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 generate vibrations, causing the event camera to be tested to respond and output a target image;

[0009] S3: Determine the target generation time according to the data stream and the custom identifier in step S2;

[0010] S4: Taking the target generation time determined in step S3 as a reference, obtain a 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 event camera to be tested.

[0011] Further, 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, the light source irradiates 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 generate vibration.

[0012] Further, in step S2: When the event camera to be measured receives the control signal, the event camera to be measured 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 measured responds to generate and output a corresponding target image.

[0013] Further, in step S3: Determine the moment t when the custom identifier is located in the data stream. If there is no target image in the projected image of the data stream within the preset time period, record the moment t as the target generation time, otherwise repeat steps S1 to S3.

[0014] A test system for the target perception time of an event camera includes: a light source module that emits a light beam to the event camera to be measured; a target that is arranged in the light source module and is photographed by the event camera to be measured to obtain a corresponding target image; a control module that sends a synchronous control signal to the light source module and the event camera to be measured, and determines the target perception time of the event camera to be measured according to the data stream from the event camera to be measured.

[0015] Further, 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 irradiates the tail of the collimator, so that the collimator emits parallel light to the event camera; the trigger motor receives the synchronous control signal and controls the target to generate vibration.

[0016] Further, the light source is a stroboscopic-free light source.

[0017] Further, the control module sends a synchronous control signal to the light source module and the event camera to be measured; when the event camera to be measured receives the synchronous control signal, the imaging device event trigger detector in the event camera to be measured inserts a custom identifier into the data stream and transfers the data stream with the custom identifier to the control module; when the light source module receives the synchronous control signal, it controls the target to vibrate, so that the event camera to be measured responds to generate and output a corresponding target image.

[0018] Further, in the control module, determine the moment t when the custom identifier is located in the received data stream. If there is no target image in the projected image of the data stream within the preset time period, record the moment t as the target generation time; taking the target generation time as a reference, obtain the projected image of the data stream along the time axis. When a target image is obtained in the projected image, the difference between the current moment and the target generation time is the target perception time of the event camera to be measured.

[0019] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0020] (1) In the test method and system for the target perception time of an event camera according to the present invention, by using a synchronous triggering method, while the target vibration causes the event camera to respond, an identifier is inserted into the output data of the event trigger detector of the imaging device of the event camera, and the target generation time is confirmed in the output data; the test method is simple, and the measurement of the target perception time of the event camera can be completed quickly, effectively and with high accuracy;

[0021] (2) In the test method and system for the target perception time of an event camera according to the present invention, a stroboscopic-free light source is used for testing to avoid the interference caused by micro-vibration and light source flicker. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 is a schematic flow chart of the test method for the target perception time of an event camera according to the embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of the test system for the target perception time of an event camera according to the embodiment of the present invention.

[0025] Description of the reference numerals in the drawings:

[0026] 1. Light source module; 2. Target; 3. Control module; 4. Event camera to be tested; 5. Light source; 6. Collimator; 7. Trigger motor; 8. Optical platform. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0028] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 should not be construed as a limitation to 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 specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0031] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0032] As Figure 1 shown, the test method for the target perception time of an event camera according to the embodiment of the present invention includes:

[0033] S1: Set a target in the light source module; control the light source module to emit a light beam towards the event camera to be tested.

[0034] 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 irradiates the tail of the collimator, causing the collimator to emit parallel light towards the event camera to be tested; the trigger motor controls the target to generate vibrations.

[0035] 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 in the output data stream, and the light source module controls the target to generate vibrations, causing the event camera to be tested to respond and output a target image.

[0036] In some embodiments, 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, causing the event camera to be tested to respond and generate an output corresponding target image. It should be noted that the event camera to be tested inserts a custom identifier into the data stream and triggers the motor to control the vibration of the target simultaneously, so as to achieve synchronous triggering.

[0037] S3: Determine the target generation time according to the data stream and the custom identifier in step S2.

[0038] In some embodiments, in step S3: Determine the moment t when the custom identifier is located in the data stream. If there is no target image in the projected image of the data stream within the preset time period, record the moment t as the target generation time; otherwise, repeat steps S1 to S3. The preset time period can be adjusted adaptively according to the actual situation. In one embodiment, the time period [t - 1, t] between the moment t and the previous millisecond t - 1 is set as the preset time period.

[0039] S4: Taking the target generation time determined in step S3 as a reference, obtain the projected image of the data stream along the time axis. When the target image generated in step S2 is obtained in the projected image, the difference between the current moment and the target generation time is the target perception time of the event camera to be tested.

[0040] In a specific embodiment, taking the target generation time t as a reference and in milliseconds, sequentially obtain the projected images of the data stream on the time axis in the time periods [t, t + 1], [t, t + 2],..., [t, t + ∆t] until the target image is obtained in the projected image. At this time, the difference ∆t between the current moment t + ∆t and the target generation time t is the target perception time.

[0041] According to the test method for the target perception time of an event camera provided by the embodiments of the present invention, the present invention correspondingly provides a test system for the target perception time of an event camera, as Figure 2 shown, including a light source module 1, a target 2, and a control module 3. Among them, 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 synchronous 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.

[0042] 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 to the tail of the collimator 6. The light source 5 irradiates the tail of the collimator 6, causing the collimator 6 to emit parallel light toward the event camera 4. The trigger motor 7 receives a synchronous 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 measured are placed on an optical platform 8. At the same time, the light source 5 preferably uses a stroboscopic-free light source to avoid interference caused by micro-vibrations and light source flicker. In addition, to simplify the test system, the trigger motor 7 preferably uses a patch-type micro-motor. The patch-type micro-motor is attached to the target 2 behind the collimator 6. When the patch-type micro-motor receives the synchronous control signal from the control module 3, it controls the target 2 to vibrate. Finally, the control module 3 preferably sends a periodic synchronous control signal to the light source module 1 and the event camera 4 to be measured. The periodic synchronous control signal can collect data multiple times in one test, increasing the number of valid data.

[0043] The control module 3 sends a synchronous control signal to the light source module 1 and the event camera 4 to be measured. When the event camera 4 to be measured receives the synchronous control signal, the imaging device event trigger detector in the event camera 4 to be measured inserts a custom identifier into the data stream and transfers 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 synchronous control signal, it controls the target 8 to vibrate, causing the event camera to be measured to respond and output a corresponding target image.

[0044] In the control module 3, determine the moment t when the custom identifier is located in the received data stream. If there is no target image in the projected image of the data stream within a preset time period, record the moment t as the target generation time. Based on the target generation time, obtain the projected image of the data stream along the time axis. When a target image is obtained in the projected image, the difference between the current moment and the target generation time is the target perception time of the event camera to be measured. The preset time period can be adjusted adaptively according to the actual situation. In an embodiment, the time period [t - 1, t] between the moment t and the previous second t - 1 is set as the preset time period.

[0045] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the disclosure of the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved. This is not limited herein.

[0046] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within 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: determining the target generation time according to the data stream and the custom identifier in step S2, including: determining 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 in a preset time period, recording the time t as the target generation time, otherwise repeating steps S1 to S3; 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. 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; A control module sends a synchronization control signal to the light source module and the event camera to be tested, and 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 measured responds to generate and output a corresponding target image; The control module determines 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 in the preset time period, records the time t as the target generation time; The control module obtains the projection image of the data stream along the time axis based on the target generation time. 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.

5. The test system for event camera target perception time according to claim 4, 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.

6. The test system for event camera target perception time according to claim 5, characterized in that: The light source is a non-stroboscopic light source.

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