Method and system for object detection assessment

Abstract

A method (100) and a system (500) for object detection assessment are provided. The method comprises detecting (110) an object (120) by a camera, determining (130) a first brightness level, B1, of the object, in a first image (140) captured by the camera, activating (150) the light source for at least partial illumination of the object, determining (160) asecond brightness level, B2, of the object, in a second image (170) captured by the camera, determining (180) a difference, D, between the second brightness level, B2, and the first brightness level, B1, transmitting (190), if the difference, D, is above a first threshold, T1, a trigger signal (200) indicative of a positive object detection, and determining (210), if the difference, D, is below a second threshold, T2, wherein T2 < T1, that the object is located between the camera and the light source, and refraining from transmitting the trigger signal.

Description

[0001] 2024PF80153

[0002] 1

[0003] Method and system for object detection assessment

[0004] FIELD OF THE INVENTION

[0005] The present invention generally relates to a method and system for object detection assessment.

[0006] BACKGROUND OF THE INVENTION

[0007] There are numerous camera-based systems, e.g. security systems, in the prior art which are able to detect motion by image (picture) analysis. Systems of this kind may be provided at substantially any types of environments and / or establishments, such as homes, offices, buildings, etc.

[0008] It should be noted that these systems may suffer from ‘false alarms’ due to detection of objects which the systems are primarily not arranged react upon via e.g. alarms. More specifically, as the intention of the systems is to detect and react upon relatively large objects (e.g. intruders), it is undesirable that relatively small objects (near the camera lens) are detected and reacted upon by the systems. For example, a spider web or a bug nearby the lens may cause changes on enough camera pixels to trigger false alarms. In general, it is difficult for motion sensing via camera video to assess the size of an object and this whether to trigger an alert.

[0009] Attempts in the prior art trying to overcome this problem are often complex, cumbersome and / or error-prone. As a consequence, the desire to achieve a convenient system is not met by the prior art and / or false alarms may still be triggered by the systems at hand.

[0010] Hence, it is an object of the present invention to try to overcome at least some of the drawbacks of present camera-based techniques / technologies for motion detection, and to provide a motion detection technique / technology which is convenient, efficient, and avoids (or even eliminates) false alarms.

[0011] US20200162653 discloses a signal processing system which includes: an illumination section; an image capturing section; a parameter control section; and an acquisition section. The illumination section emits laser light to a target. The image capturing section captures an image of the target irradiated with the laser light. The parameter control section changes a parameter related to image capturing of at least one of the illumination 2024PF80153

[0012] 2 section or the image capturing section within exposure time of the image capturing section. The acquisition section acquires movement information related to movement of the target on the basis of an image signal of the target whose image is captured by the image capturing section.

[0013] SUMMARY OF THE INVENTION

[0014] It is of interest to overcome at least some of the deficiencies of camera-based motion detection systems according to present technologies, and to provide a motion detection technique / technology which is convenient, efficient, and avoids (or even eliminates) false alarms.

[0015] This and other objects are achieved by providing a method and a system having the features in the independent claims. Preferred embodiments are defined in the dependent claims.

[0016] According to a first aspect of the present invention, there is provided a method for object detection assessment via a system comprising an image-capturing device and a light source predeterminedly positioned with respect to the image-capturing device. The method comprises detecting an object by the image-capturing device. The method further comprises determining a first brightness level, Bi, of the object, in a first image captured by the imagecapturing device. The method further comprises activating the light source for at least partial illumination of the object. The method further comprises determining a second brightness level, B2, of the object, in a second image captured after activation of the light source by the image-capturing device. The method further comprises determining a difference, D, between the second brightness level, B2, and the first brightness level, Bi. The method further comprises transmitting, if the difference, D, is above a first threshold, Ti, a trigger signal indicative of a positive object detection. The method further comprises determining, if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object is located between the image-capturing device and the light source, and refraining from transmitting the trigger signal.

[0017] According to a second aspect of the present invention, there is provided a system arranged for object detection assessment. The system comprises an image-capturing device, and a light source predeterminedly positioned with respect to the image-capturing device. The system is configured to detect an object by the image-capturing device, and to determine a first brightness level, Bi, of the object, in a first image captured by the image- 2024PF80153

[0018] 3 capturing device. The system is further configured to activate the light source for at least partial illumination of the object, and to determine, a second brightness level, B2, of the object, in a second image captured after activation of the light source by the image-capturing device. The system is further configured to determine a difference, D, between the second brightness level, B2, and the first brightness level, Bi, and to transmit, if the difference, D, is above a first threshold, Ti, a trigger signal indicative of a positive object detection. The system is further configured to determine, if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object is located between the image-capturing device and the light source, and refrain from transmission of the trigger signal.

[0019] Thus, the present invention is based on the idea of providing a method and a system for object detection assessment via an image-capturing device and a light source. Dependently on the position of the object with respect to the light source, a brightness level of the object may change upon activation of the light source. In case the brightness level change is relatively large, a trigger signal indicative of a positive object detection (of a relatively large object) is transmitted. In contrast, in case the brightness level change is relatively small, it is determined that the (relatively small) object is located between the image-capturing device and the light source, and refrain from transmission of the trigger signal. The object detection assessment provided by the present invention is hereby convenient, efficient, and avoids (or even eliminates) false alarms.

[0020] The present invention is advantageous in that it provides an object detection technique which is particularly convenient and efficient. Notably, by operation of the light source and assessment of the brightness level(s) of the object in the field-of-view of the image-capturing device as a result of the impingent light from the light source, the method and system may conveniently and efficiently assess whether the object is relatively distant from the light source and / or camera, implying a positive object detection and leading to a trigger signal transmission, or that the object is located between the image-capturing device and the light source, i.e. relatively close to the image-capturing device, implying a negative object detection, and refraining from a trigger signal transmission.

[0021] The present invention is advantageous in that it conveniently and efficiently avoids (or even eliminates) false alarms of objects which may be relatively close to the imagecapturing device. For example, whereas relatively small objects such as a spider web or a bug nearby a camera lens may cause changes on enough camera pixels to trigger false alarms, the present invention may conveniently and efficiently assess that this (these) object(s) may be 2024PF80153

[0022] 4 located between the image-capturing device and the light source. Consequently, by refraining from transmitting a trigger signal in this situation, false alarms may be avoided or eliminated. It should be noted that prior art method and / or systems may have difficulties in assessing the size of an object and thus whether to trigger an alert. In contrast, the present invention may expediently determine object size(s) and determine positive (or negative) object detection.

[0023] The present invention is further advantageous in that it provides an object detection assessment which comprises relatively few components (devices) and / or relatively few operations, resulting in numerous benefits, such as cost-efficiency, system arrangement (mounting) efficiency, etc.

[0024] There is provided a method for object detection assessment via a system comprising an image-capturing device. By “image-capturing device”, it is hereby meant any device configured to capture (take) one or more images, such as a camera, a video camera, or the like. The system further comprises a light source predeterminedly positioned with respect to the image-capturing device. By “predeterminedly positioned”, it is here meant that the (a) position of the light source is set or determined in advance with respect to the image-capturing device. For example, the light source may be arranged or mounted at a position at a distance and / or angle with respect to the image-capturing device and / or the field-of-view (FoV) of the image-capturing device. The method further comprises detecting an object by the imagecapturing device. By “object”, it is here meant substantially any object such as e.g. a person, animal, etc. The method further comprises determining a first brightness level, Bi, of the object, in a first image captured by the image-capturing device. Hence, a first brightness level, Bi, of the object, is determined by the image-capturing device in a first image. The method further comprises activating the light source for at least partial illumination of the object. Hence, the light source is activated from an “off’ state to an “on” state for at least partial illumination of the object. The method further comprises determining a second brightness level, B2, of the object, in a second image captured by the image-capturing device. Thus, the first brightness level, Bi, of the object, may be determined by the image-capturing device in the first image wherein the light source is in an “off’ state, and the second brightness level, B2, of the object, may be determined by the image-capturing device in the second image wherein the light source is in an “on” state. The method further comprises determining a difference, D, between the second brightness level, B2, and the first brightness level, Bi. Hence, the difference, D, between the second brightness level, B2, and the first brightness level, Bi, constitutes a brightness level difference of the object dependently on (as a result of) 2024PF80153

[0025] 5 the activation of the light source. The method further comprises transmitting, if the difference, D, is above a first threshold, Ti, a trigger signal indicative of a positive object detection. Hence, in case of a relatively large difference, D, in brightness of the object upon (after) light source activation, a trigger signal indicative of a positive object detection is transmitted. Hence, upon activation of the light source, the (surface of the) object facing the imagecapturing device may be (significantly) brighter. The method further comprises determining, if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object is located between the image-capturing device and the light source, and refraining from transmitting the trigger signal. Hence, if the condition of a relatively small difference, D, in brightness of the object upon (after) light source activation is fulfilled, it is determined that the object is located between the image-capturing device and the light source, and no trigger signal is transmitted. In other words, upon activation of the light source, the (surface of the) object facing the image-capturing device may remain relatively dark (or even become darker relative the surrounding environment).

[0026] According to an embodiment of the present invention, the image-capturing device may be positioned at an origin, OR, and the light source may be predeterminedly positioned with respect to the image-capturing device at a distance, zis, with respect to the origin, OR. By the term “distance, zis”, it is here meant a distance, a radial distance, distance component, or the like, from the origin, OR. In case of a FoV of the image-capturing device in a hemi-sphere, or part of a hemi-sphere, the term “distance, zis” may represent the radial distance from the origin, OR, or the component of the distance in the direction of the center line of the FoV.

[0027] According to an embodiment of the present invention, the distance, zis, may be in a range of 0.5-3 m. The present embodiment is advantageous as it corresponds to a medium distance from the image-capturing device.

[0028] According to an embodiment of the present invention, the step of determining, if the difference, D, is below the second threshold, T2, that the object is located between the image-capturing device and the light source, may further comprise determining that the object is located at a distance, z0, with respect to the origin, OR, which is smaller than the distance, zis, of the light source.

[0029] According to an embodiment of the present invention, the step of transmitting, if the difference, D, is above the first threshold, Ti, the trigger signal indicative of a positive 2024PF80153

[0030] 6 object detection, may further comprise determining that the object is located at a distance, z0, with respect to the origin, OR, which is larger than the distance, zis, of the light source.

[0031] According to an embodiment of the present invention, the method may further comprise selecting the light source based on at least one of automatically selecting the light source based on at least one criterion, and user input. Hence, the method may comprise selecting the light source from a plurality of light sources (i.e. at least two light sources) automatically based on one or more criteria and / or selecting the light source based on user input. The selection of the light source may hereby be performed from a plurality of light sources (already) arranged in a space, such as a room. The option of automatically selecting the light source may be based on substantially any criterion related to one or more features of the light source, such as e.g. light source position, intensity of the light source light, etc. The automatic selection may further encompass controlling (checking, e.g. at night) the light source(s) to be used for the method of the present invention. The option of selecting the light source based on user input implies that a user (person) may select, e.g. via a control, switch, or the like, which light source to use. The present embodiment is advantageous in that the versatility of the choice between automatic and manual light source selection may even further contribute to the reliability and preciseness of the operation, consequently mitigating false alarm triggers.

[0032] According to an embodiment of the present invention, the light source may be shielded in a direction towards the image-capturing device and configured to illuminate a hemi-sphere, HS, extending away from the image-capturing device. According to an alternative formulation, the image-capturing device has a field-of view, FoV, with a central axis, AFOV, and wherein the light source is shielded (in a direction) towards the imagecapturing device and configured to illuminate a hemi-sphere, HS, extending away from the image-capturing device, wherein a central axis, AHS, of the hemisphere, HS, and the central axis, AFOV, of the field-of-view, FoV, are parallel. Hence, a shield, screen, protection, or the like, may be provided to shield the light source in a direction between the light source and the image-capturing device.

[0033] According to an embodiment of the present invention, there is provided a method for object detection. The method comprises performing the method according to any one of the preceding embodiments, selecting an object for detection if the trigger signal indicative of a positive object detection is transmitted, and exempting an object for detection if determining that the object is located between the image-capturing device and the light 2024PF80153

[0034] 7 source, and refraining from transmitting the trigger signal. Hence, upon performing the method according to any one of the preceding embodiments, an object may be selected or exempted for detection based on transmission of the trigger signal indicative of a positive object detection or if the trigger signal has not been transmitted, indicative of a negative object detection, respectively. The present embodiment is advantageous in that a positive object detection conveniently allows for a (continued) detection of that object, whereas a negative object detection exempts any (continued) detection of that object. Consequently, the method of the embodiment provides an even more efficient and convenient selection of object(s) to detect.

[0035] According to an example of the present invention, there is provided a method for periodic object detection. The method comprises repeating the method according to any one of the preceding embodiments at time instants, Ti, separated by a predetermined time interval, Tp.

[0036] According to an embodiment of the system of the present invention, the imagecapturing device may be positioned at an origin, OR, and the light source is predeterminedly positioned with respect to the image-capturing device at a distance, zis, with respect to the origin, OR.

[0037] According to an embodiment of the system of the present invention, the distance, zis, may be in a range of 0.5-3 m.

[0038] According to an embodiment of the system of the present invention, the system may be configured to determine, if the difference, D, is below the second threshold, T2, that the object is located between the image-capturing device and the light source, and to determine that the object is located at a distance, z0, with respect to the origin, OR, which is smaller than the distance, zis, of the light source.

[0039] According to an embodiment of the present invention, the system may be configured to transmit, if the difference, D, is above the first threshold, Ti, the trigger signal indicative of a positive object detection, and to determine that the object is located at a distance, z0, with respect to the origin, OR, which is larger than the distance, zis, of the light source.

[0040] According to an embodiment of the present invention, the system may be further configured to select the light source based on, at least one of, automatically select the light source based on at least one criterion, and user input. 2024PF80153

[0041] 8

[0042] According to an embodiment of the present invention, the system may be configured to select an object for detection if the trigger signal indicative of a positive object detection is transmitted, and exempt an object for detection if determined that the object is located between the image-capturing device and the light source, and to refrain from transmission of the trigger signal.

[0043] Further objectives of, features of, and advantages with, the present invention will become apparent when studying the following detailed disclosure, the drawings and the appended claims. Those skilled in the art will realize that different features of the present invention can be combined to create embodiments other than those described in the following.

[0044] BRIEF DESCRIPTION OF THE DRAWINGS

[0045] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

[0046] Figs, la and lb schematically show a system and its operation according to an exemplifying embodiment of the present invention.

[0047] Figs. 2, 3a and 3b schematically show a system according to exemplifying embodiments of the present invention.

[0048] Fig. 4 schematically shows a method according to an exemplifying embodiment of the present invention.

[0049] DETAILED DESCRIPTION

[0050] Fig. la schematically shows a system 500 arranged for object detection assessment according to an exemplifying embodiment of the present invention. The system 500 comprises an image-capturing device 510, which may be substantially any device configured to capture (take) one or more images, such as a camera, a video camera, or the like. The system 500 further comprises a light source 520 predeterminedly positioned with respect to the image-capturing device 510. In Fig. la, the (a) position of the light source 520 is set or determined in advance with respect to the image-capturing device 510. For example, the light source 520 may be arranged or mounted at a position at a distance and / or angle with respect to the image-capturing device 510 and / or the field-of-view (FoV) of the imagecapturing device 510. The placement of the light source 520 may be within the FoV or outside the FoV of the image-capturing device 510. The light source 520 may be positioned at a medium distance from the image-capturing device 510. The system 500 is configured to 2024PF80153

[0051] 9 detect an object 120 by the image-capturing device 510, wherein the object 120 is exemplified as a person in the right hand side of Fig. la and as a spider in the left hand side of Fig. la. According to this example of Fig. la, the light source 520 is positioned between the imagecapturing device 510 and the object (person) 120, whereas the object (spider) 120 is located between the image-capturing device 510 and the light source 520.

[0052] Fig. lb schematically shows an operation or process of the system 500 arranged for object detection assessment according to the system as described in Fig. la. The system 500 is configured to determine a first brightness level, Bi, of the object 120, in a first image 140 captured by the image-capturing device 510 before the light source 520 is activated. The system 500 is further configured to activate the light source 520 for at least partial illumination of the object 120. The system 500 is further configured to determine after activation of the light source 520, a second brightness level, B2, of the object, in a second image 170 captured after activation of the light source 520 by the image-capturing device 510. Thus, the first brightness level, Bi, of the object 120, may be determined by the imagecapturing device 510 in the first image 140 wherein the light source 520 is in an “off’ state or a low dim state (e.g. 1-25% brightness), and the second brightness level, B2, of the object 120, may be determined by the image-capturing device 510 in the second image 170 wherein the light source 520 is in an “on” state or a higher dim state (e.g. 50-100% brightness), respectively. The system 500 is further configured to determine 180 a difference, D, between the second brightness level, B2, and the first brightness level, Bi. The system 500 is further configured to transmit 190, if the difference, D, is above a first threshold, Ti, a trigger signal 200 indicative of a positive object detection. Hence, in case of a relatively large difference, D, in brightness of the object 120 upon (after) light source activation, a trigger signal 200 indicative of a positive object detection is transmitted. The system 500 is further configured to determine 210, if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object 120 is located between the image-capturing device 510 and the light source 520, and refraining from transmitting the trigger signal. Hence, if the condition of a relatively small difference, D, in brightness of the object 120 upon (after) light source activation is fulfilled, it is determined that the object 120 is located between the image-capturing device 510 and the light source 520, and no trigger signal is transmitted.

[0053] According to the example of Fig. la, wherein the object 120 is exemplified as a person in the right hand side of Fig. la, the light source 520 is located between the imagecapturing device 510 and the object 120. Consequently, the brightness of the object 120, 2024PF80153

[0054] 10 registered by the image capturing device 510, upon activation of the light source 520, increases significantly, and the system 500 may hereby determine that the difference, D, between the second brightness level, B2, of the object 120 in the second image 170 and the first brightness level, Bi, of the object 120 in the first image 140 is relatively large. As a result, a trigger signal 200 indicative of a positive object detection of the (relatively large) object (person) 120 is transmitted. In contrast, for the object 120 exemplified as a spider in the left hand side of Fig. la, the object 120 is located between the image-capturing device 510 and the light source 520. Consequently, the increase of the brightness of the object 120, registered by the image capturing device 510, upon activation of the light source 520, is relatively small (or may almost be negligible). The system 500 may hereby determine that the difference, D, between the second brightness level, B2, of the object 120 in the second image 170 and the first brightness level, Bi, of the object 120 in the first image 140 is relatively small. Hence, the system 500 may determine that the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the (relatively small) object (spider) 120 is located between the image-capturing device 510 and the light source 520, and refraining from transmitting the trigger signal.

[0055] Fig. 2 schematically shows a system 500 arranged for object detection assessment according to an exemplifying embodiment of the present invention. It should be noted that the system 500 as presented in Fig. 2 corresponds to the system 500 as presented in Fig. la, and it is hereby also referred to Fig. la for an increased understanding of the features and / or functions of the system 500.

[0056] In Fig. 2, the (a) position of the light source 520 is set or determined in advance with respect to the image-capturing device 510. As exemplified in Fig. 2, the image-capturing device 510 is positioned at an origin, OR, and the light source 520 is predeterminedly positioned with respect to the image-capturing device 510 at a distance, zis, with respect to the origin, OR, and at angle, a, with respect to a center (line) of the FoV. The light source 520 is arranged at an absolute distance, dis, from the image-capturing device 510 as indicated. The distance, zis, and / or the absolute distance, dis, may be in a range of 0.5-3 m.

[0057] The system 500 may be configured to determine, if the difference, D, between the second brightness level, B2, of the object 120 in the second image and the first brightness level, Bi, of the object 120 in the first image is below the second threshold, T2, that the object 120 is located between the image-capturing device 510 and the light source 520, which corresponds to the position of the object (spider) 120 in Fig. 2. The system 500 may hereby 2024PF80153

[0058] 11 determine that the object 120 is located at a distance, zi, with respect to the origin, OR, which is smaller than the distance, zis. Accordingly, the system 500 may determine that the object 120 is located between the image-capturing device 510 and the light source 520, and may refrain from transmission of the trigger signal.

[0059] Analogously, the system 500 may be configured to transmit, if the difference, D, is above the first threshold, Ti, the trigger signal indicative of a positive object detection, and to determine that the object (person) 120 is located at a distance, Z2, with respect to the origin, OR, which is larger than the distance, zis, of the light source.

[0060] Figs. 3a and 3b schematically show (a) concept(s) of the system 500 arranged for object detection assessment according to an exemplifying embodiment of the present invention. Hence, Fig. 3a and 3b represent different interpretations of the system 500. It should be noted that the system(s) 500 as presented in Figs. 3a and 3b correspond(s) to the system 500 as presented in Fig. la, and it is hereby also referred to Fig. la for an increased understanding of the features and / or functions of the system(s) 500.

[0061] In Fig. 3 a, an arrangement of the image-capturing device 510 and the light source 520 of the system 500 is shown to represent a first position of the object 120 (righthand side of Fig. 3a) wherein the light source 520 is positioned between the image-capturing device 510 and the object 120, as well as a second position of the object 120 (left-hand side of Fig. 3a), wherein the object 120 is positioned between the image-capturing device 510 and the light source 520. The object 120 is positioned along an (imaginary) axis, x, in the FoV of the image-capturing device 510 for both (first and second) positions. According to the previously described operation or process of the system 500, the object 120 may be detected by the image-capturing device 510, and the system 500 may be configured to determine a difference, D, between the second brightness level, B2, of the object 120 in the second image and the first brightness level, Bi, of the object 120 in the first image, after activation of the light source 520. If the angle, a, from the axis, x, to the light source 520 fulfills e.g. |a| < 90° as exemplified by ai (theoretical, as e.g. |a| < 75° may constitute an alternative criterion) as exemplified by the object 120 in the first position (right-hand side of Fig. 3a), the object 120 will become brighter upon activation of the light source 520. Accordingly, and in other words, as the difference, D, hereby is above a first threshold, Ti, a trigger signal indicative of a positive object detection is transmitted by the system 500. Hence, in this case, if the object 120 appears large enough for the image-capturing device 510, the system 500 may transmit a trigger signal indicative of a positive object detection. In contrast, if the angle, a, from the 2024PF80153

[0062] 12 axis, x, to the light source 520 fulfills e.g. |a| > 90° as exemplified by a? (theoretical, as e.g. |a| > 105° may constitute an alternative criterion), as exemplified by the object 120 in the second position (left-hand side of Fig. 3a), the background (and / or other objects) will become brighter than the object 120 upon activation of the light source 520. Hence, in this case, namely that the difference, D, hereby is below a second threshold, T2, the object 120 does not appear large enough for the image-capturing device 510, and the system 500 refrains from transmitting the trigger signal.

[0063] In Fig. 3b, a (single) light source 520 is shown in a first position, wherein the light source 520 is positioned between the image-capturing device 510 and the object 120, as well as in a second position, wherein the object 120 is positioned between the imagecapturing device 510 and the light source 520. The object 120 is positioned along an (imaginary) axis, x, in the FoV of the image-capturing device 510. According to the previously described operation or process of the system 500, the object 120 may be detected by the image-capturing device 510, and the system 500 may be configured to determine a difference, D, between the second brightness level, B2, of the object 120 in the second image and the first brightness level, Bi, of the object 120 in the first image, after activation of the light source 520. If the angle, a, from the axis, x, to the light source 520 fulfills e.g. |a| < 90° as exemplified by ai (theoretical, as e.g. |a| < 75° may constitute an alternative criterion) as exemplified by the light source 520 in the first position, the object 120 will become brighter upon activation of the light source 520. Accordingly, and in other words, as the difference, D, hereby is above a first threshold, Ti, a trigger signal indicative of a positive object detection is transmitted by the system 500. Hence, in this case, if the object 120 appears large enough for the image-capturing device 510, the system 500 may transmit a trigger signal indicative of a positive object detection. In contrast, if the angle, a, from the axis, x, to the light source 520 fulfills e.g. |a| > 90° as exemplified by 012 (theoretical, as e.g. |a| > 105° may constitute an alternative criterion), as exemplified by the light source 520 in the second position, the background (and / or other objects) will become brighter than the object 120 upon activation of the light source 520. Hence, in this case, namely that the difference, D, hereby is below a second threshold, T2, the object 120 does not appear large enough for the image-capturing device 510, and the system 500 refrains from transmitting the trigger signal.

[0064] Fig. 4 schematically shows a flow chart of a method 100 arranged for object detection assessment according to an exemplifying embodiment of the present invention. The method 100, performed via a system comprising an image-capturing device and a light source 2024PF80153

[0065] 13 predeterminedly positioned with respect to the image-capturing device, comprises detecting 110 an object by the image-capturing device. The method 100 further comprises determining 130 a first brightness level, Bi, of the object, in a first image captured by the image-capturing device. The method 100 further comprises activating 150 the light source for at least partial illumination of the object. The method 100 further comprises determining 160 a second brightness level, B2, of the object, in a second image captured by the image-capturing device after activation of the light source. The method 100 further comprises determining 180 a difference, D, between the second brightness level, B2, and the first brightness level, Bi. The method 100 further comprises transmitting 190, if the difference, D, is above a first threshold, Ti, a trigger signal indicative of a positive object detection. The method 100 further comprises determining 210, if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object is located between the image-capturing device and the light source, and refraining from transmitting the trigger signal.

[0066] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the imagecapturing device 510, the light source 520, the object 120, etc., may have different positions, dimensions and / or sizes than those depicted / described.

Claims

2024PF8015314CLAIMS1. A method (100) for object detection assessment via a system (500) comprising an image-capturing device (510) and a light source (520) predeterminedly positioned with respect to the image-capturing device, the method comprising detecting (110) an object (120) by the image-capturing device, determining (130) a first brightness level, Bi, of the object, in a first image (140) captured by the image-capturing device, activating (150) the light source for at least partial illumination of the object, determining (160) a second brightness level, B2, of the object, in a second image (170) captured after activation of the light source by the image-capturing device, determining (180) a difference, D, between the second brightness level, B2, and the first brightness level, Bi, transmitting (190), if the difference, D, is above a first threshold, Ti, a trigger signal (200) indicative of a positive object detection, determining (210), if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object is located between the image-capturing device and the light source, and refraining from transmitting the trigger signal.

2. The method according to claim 1, wherein the image-capturing device is positioned at an origin, OR, and the light source is predeterminedly positioned with respect to the image-capturing device at a distance, zis, with respect to the origin, OR.

3. The method according to claim 2, wherein the distance, zis, is in a range of 0.5- 3 m.

4. The method according to claim 2 or 3, wherein the step of determining, if the difference, D, is below the second threshold, T2, that the object is located between the imagecapturing device and the light source, further comprises determining that the object is located at a distance, zi, with respect to the origin, OR, which is smaller than the distance, zis, of the light source.2024PF80153155. The method according to any one of claims 2-4, wherein the step of transmitting, if the difference, D, is above the first threshold, Ti, the trigger signal indicative of a positive object detection, further comprises determining that the object is located at a distance, Z2, with respect to the origin, OR, which is larger than the distance, zis, of the light source.

6. The method according to any one of the preceding claims, further comprising selecting (300) the light source based on at least one of automatically selecting the light source based on at least one criterion, and user input.

7. The method according to any one of the preceding claims, wherein the light source is shielded in a direction towards the image-capturing device and configured to illuminate a hemi-sphere, HS, extending away from the image-capturing device.

8. A method (400) for object detection, comprising performing the method according to any one of the preceding claims, selecting an object for detection if the trigger signal indicative of a positive object detection is transmitted, and exempting an object for detection if determining that the object is located between the image-capturing device and the light source, and refraining from transmitting the trigger signal.

9. A system (500) arranged for object detection assessment, comprising an image-capturing device (510), and a light source (520) predeterminedly positioned with respect to the imagecapturing device, wherein the system is configured to detect an object (120) by the image-capturing device, determine a first brightness level, Bi, of the object, in a first image (140) captured by the image-capturing device, activate the light source for at least partial illumination of the object, determine a second brightness level, B2, of the object, in a second image (170) captured after activation of the light source by the image-capturing device,2024PF8015316 determine (180) a difference, D, between the second brightness level, B2, and the first brightness level, Bi, transmit, if the difference, D, is above a first threshold, Ti, a trigger signal (200) indicative of a positive object detection, determine, if the difference, D, is below a second threshold, T2, wherein T2 < Ti, that the object is located between the image-capturing device and the light source, and refrain from transmission of the trigger signal.

10. The system according to claim 9, wherein the image-capturing device is positioned at an origin, OR, and the light source is predeterminedly positioned with respect to the image-capturing device at a distance, zis, with respect to the origin, OR.

11. The system according to claim 10, wherein the distance, zis, is in a range of 0.5-3 m.

12. The system according to claim 10 or 11, wherein the system is configured to determine, if the difference, D, is below the second threshold, T2, that the object is located between the image-capturing device and the light source, and to determine that the object is located at a distance, zi, with respect to the origin, OR, which is smaller than the distance, zis, of the light source.

13. The system according to any one of claims 10-12, wherein the system is configured to transmit, if the difference, D, is above the first threshold, Ti, the trigger signal indicative of a positive object detection, and to determine that the object is located at a distance, Z2, with respect to the origin, OR, which is larger than the distance, zis, of the light source.

14. The system according to any one of claims 9-13, wherein the system is further configured to select the light source based on at least one of automatically select the light source based on at least one criterion, and user input.2024PF801531715. The system according to any one of claims 9-14, wherein the system is configured to select an object for detection if the trigger signal indicative of a positive object detection is transmitted, and exempt an object for detection if determined that the object is located between the image-capturing device and the light source, and to refrain from transmission of the trigger signal.

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