WO2017115060A1 - System for measuring the frequenting of a reception area and method for estimating the crossing of an associated threshold - Google Patents

Abstract

The invention relates to a system for measuring the frequenting of a reception area (ZA). More generally, the invention relates to a system and a method (100) for estimating the direction of crossing of a threshold (SP) performed by a subject (Si) entering or leaving said reception area (ZA). The crossing of said threshold by the subject can be carried out from an area of interest (ZI) opposite said threshold (SP) to the reception area (ZA) or, on the contrary, from the reception area (ZA) to said area of interest (ZI).

Description

 System for measuring the attendance of a reception zone and method for estimating the crossing of an associated threshold

The invention relates to a system for measuring the attendance of a reception area.

 More generally, the invention relates to a system for estimating the direction of crossing a threshold by a subject entering or leaving said reception area. The crossing of said threshold by the subject may be effected from an area of interest, situated opposite said threshold, towards the reception zone, when the subject enters the reception zone or, conversely, the zone reception to said area of interest, when said subject leaves said reception area. According to a preferred embodiment, the invention also makes it possible to identify a subject visiting a reception area, or even a plurality of visitors or simply accompanying subjects of the identified subject. A system according to the invention can then know the incoming and outgoing flows of the reception area. It can trigger actions implemented by a third electronic entity, depending on the crossing of said threshold, such as by way of non-limiting example, the extinction of light sources via home automation devices when crossing the threshold. from the reception area to the area of interest.

 For the purposes of the invention and throughout the document, we mean by "threshold" any opening through which a subject passes from a first predefined space to a second predefined space.

As an example of a preferred but nonlimiting application, the invention will be described in connection with the rental of houses, apartments, meeting rooms, reception or more generally of real estate or reception areas. It could however be exploited by an individual wishing to monitor the comings and goings of subjects in the immediate vicinity of his property.

 More and more individuals are leasing their real estate during their absences, for a fixed sleeping number. However, once the keys have been handed over, it is impossible for the property manager to know how many people actually sleep or enter. For example, an apartment can be rented for four beds while ten people will stay there. In addition, said manager can not know the actions of tenants and ensure that the property is well operated within the framework defined by the lease. For example, it is necessary to know immediately if a furnished apartment does not find itself exploited fraudulently by an unscrupulous tenant, for example as a reception room for a wedding.

 There are different solutions on the market to monitor the entrances and exits of subjects authorized to occupy a property. A first solution is to employ a concierge or a receptionist who takes note of the entries, exits and identities of said subjects, as can be seen in some hotels. This solution is however expensive and very difficult to implement, especially for an individual who does not rent his property occasionally.

An alternative solution is to install surveillance cameras, which constantly film the entrance to a property, or even the interior of the property. However, this solution is very intrusive in the privacy of occupants and contrary to the laws of some countries. In addition, such a solution requires a processing of the images captured by said cameras in deferred time, to humanely analyze the outputs and the entrances of visitors and to count the number of subjects having stayed within said property.

Other security and surveillance systems offer door sensor detection using sensors. Examples of systems include infrared barriers. Such barriers are generally installed in the lower part of a door frame. The manager of a property can thus know the number of door crossings and, consequently, the number of visitors during a given period of time. However, such a system comprising an infrared barrier may, for example, deliver a number of threshold crossings difficult to interpret. Thus, suppose that such a system detects ten crossings of a threshold of a door, said door allowing access to an apartment from a parking area for an hour or a day. Such a result, that is to say "ten crossings", does not in itself make it possible to know if one and the same person made five trips between the property and his car to load or unload the latter, or if ten different persons have taken turns to enter the said property. It can not be determined whether six persons are returned to the property then four came out, etc.

 To really know the attendance of a reception area, it is necessary to estimate not only a crossing of a threshold, but also the direction of said crossing of threshold. Knowledge of the meaning of the crossing makes it possible to correctly count the entries and exits of subjects. The current techniques, except to mobilize human resources to analyze the attendance of a reception area, do not allow to implement automatic and simple solutions measuring in real time the attendance of a reception area.

In an attempt to address this problem, some reception area managers provide for a separate exit door and entrance door, each equipped with sensors in communication with a traffic crossing analysis system. thresholds of said doors. This solution is however restrictive and difficult to implement. It is necessary to provide two separate access routes, which is almost impossible in the majority of reception areas, such as apartments for example. Such a solution also requires the installation of several crossing detection devices, thus increasing the costs associated with the acquisition and maintenance of equipment. Moreover, this solution does not make any concrete sense, because it is almost impossible to force visitors to respect the direction of crossing required by each door. The invention makes it possible to meet all the disadvantages raised by the known solutions. Among the numerous advantages provided by the invention, we can mention that a system implementing a threshold crossing method according to the invention is discrete and compact, that is to say that it does not does not require large physical arrangements of the reception area that one wishes to observe. Such a threshold crossing estimation method can be implemented iteratively at programmed periods, or even at the request. The invention makes it possible to make a tenant aware of the respect of his rental contract, and to reassure the landlord about his property and the seriousness of the tenant. The invention makes it possible to count the number of crossings entering and leaving an opening and thus to estimate the number of subjects having visited the property and / or occupying said property, when the threshold observed delimits the access to a closed reception area. , such as a room or an apartment. In addition, the invention may possibly make it possible to identify a subject, that is to say to distinguish a subject from a plurality. For example, it is possible to identify a subject and count the number of people accompanying it. Finally, the invention provides for triggering actions by third-party electronic entities that depend on the direction of crossing the threshold observed, such as, for example, the transmission of an informative message to the property manager. , including the identifier of a subject entering or leaving the receiving area, a timestamp crossing the threshold, or even the number of subjects accompanying the identified subject, etc.

For this purpose, a method is especially provided for estimating a threshold crossing by a subject, implemented by a processing unit co-operating with one or more means for capturing an area of interest with respect to said threshold and producing a digital representation of said area for a given period, and storage means, the storage means recording said digital representation. To detect the presence or absence of a subject in the area of interest, said method comprises:

 a step for triggering the capture of the area of interest and producing a digital representation of said area of interest for the current period;

 a step for analyzing said digital representation and detecting the presence of a subject in the area of interest or attesting to the absence of a subject in said area of interest.

To estimate a crossing threshold from the area of interest, the storage means stores the value of a minimum distance of the subject from the threshold estimated in a previous period. The process therefore comprises:

a step for estimating a minimum distance of the subject from the threshold during the current period when the step for analyzing the digital representation detects the presence of the latter in the zone of interest or for it assigning a predetermined value characterizing a lack of estimation if said step for analyzing the digital representation attests to the absence of said subject; a step for reading the value of the minimum distance of the subject from the threshold during the preceding period;

 a step for estimating a crossing of the threshold of the subject from the area of interest if:

 · The value of the minimum distance during the current period is equal to the predetermined value characterizing a lack of estimation;

 • the value of the minimum distance in the previous period is different from a predetermined value indicating the absence of an estimate;

 Said estimated value of the minimum distance of the subject from a threshold during the preceding period is less than a predetermined distance characterizing a narrow observation band close to the threshold;

a step for replacing the estimated value of the minimum distance of the subject from the threshold in the previous period by the value of the minimum distance during the current period. To estimate a threshold crossing to the area of interest, the method may include a step, subsequent to the step for reading the value of the minimum distance of the subject from the threshold in the previous period, to compare the value of the minimum distance of the subject from the threshold during the current period to the predetermined distance characterizing a narrow band of observation close to the threshold and to estimate a threshold crossing of the subject to the area of interest if:

 the value of the minimum distance during the current period is different from the predetermined value attesting to the absence of estimation;

 the value of the minimum distance estimated during a preceding period is equal to a predetermined value attesting to the absence of estimation;

 the value of the estimated minimum distance of the subject from the threshold during the current period is less than the value of the predetermined distance characterizing a narrow observation band close to the threshold.

To detect the presence of several subjects and to estimate the threshold crossing of each of said subjects, the storage means may comprise one or more recordings respectively associated with one or more subjects, including a subject identifier and the value of a minimum distance. subject compared to a threshold estimated in a previous period. The step of analyzing the digital representation of the area of interest during a current period and detecting the presence of a subject may furthermore, to identify said subject. The step of reading the value of the minimum distance of the identified subject, compared to the threshold in the previous period, may consist of reading the record associated with said identified subject.

Said method may further comprise a step for encoding and triggering the transmission of a data message to a third party entity in communication with said processing unit, comprising data representing an estimated threshold crossing by the subject during current period from or to the area of interest. To estimate the attendance of a reception area, said method may comprise a step for crediting a counter accounting for threshold crossings by the subject from the area of interest or towards said area of interest.

According to a second object, the invention provides a computer program product comprising program instructions that can be used by a processing unit cooperating with one or more means of capturing an area of interest with respect to a threshold and for producing a digital representation of said area, and storage means, the storage means recording said digital representation and the value of a minimum distance of the subject from a threshold which, when executed or interpreted by said processing unit, trigger the implementation of a method for estimating a threshold crossing according to the invention.

According to a third object, the invention provides an electronic device comprising a processing unit cooperating with capture means and storage means. Said electronic device is adapted in that it comprises in the storage means instructions of a computer program product as mentioned above.

According to a third object, the invention provides a system for measuring the attendance of a reception zone comprising an electronic device according to the invention and cooperating with one or more means of capturing a zone of interest in the form of screw a threshold and producing a digital representation of said area for a given period, and storage means, the storage means recording said digital representation.

Other characteristics and advantages will appear more clearly on reading the description which follows, referring to an exemplary embodiment given by way of indication and not limitation, and to the examination of the figures which accompany it, among which:

FIG. 1 depicts a functional diagram of a system for measuring the attendance of a reception zone comprising a capture means and a processing unit for implementing a method for estimating the crossing of a threshold according to the invention; FIG. 2 depicts a block diagram of a method for estimating the crossing of a threshold according to the invention;

 - Figure 3 describes a scene of interest observed by a system according to the invention;

 FIGS. 4a and 4b describe exemplary scenarios of the operation of such a method or system.

As an example of a preferred but nonlimiting application, the invention will be described through an application relating to the estimation of the inputs and outputs of a subject in an apartment.

A scene of interest according to the invention, in connection with said apartment, comprises the interior of the apartment, an access road and the space located in front of the access road outside the apartment. represented respectively by a reception zone ZA, a threshold SP and a zone of interest ZI, as described in FIG. 3. The zone of interest ZI is the zone observed by means of catches MC, located as non-limiting example around the SP threshold. The zone of interest ZI includes a zone ZIP close to the threshold SP. Said ZIP zone is characterized by a narrow observation band of width _{equal to} the threshold SP.

FIG. 1 presents a system for measuring the attendance of a reception zone, for example that described with reference to FIG. 3, comprising a capture means MC cooperating with a processing unit UT. The latter is responsible for collecting the data provided by the capture means MC and to estimate a threshold crossing. The capture means MC may measure one or more quantities related to the environment of the zone of interest ZI to enable detection of the presence of a subject in said zone of interest ZI located opposite said threshold, As represented in FIG. 3, the capture means MC therefore produces a digital representation R (t) of the zone of interest ZI. The latter is then recorded in memory means MM cooperating with the processing unit UT. According to a preferred embodiment, the recording of a temporal datum t characterizing the current period can be jointly performed with that of the digital representation R (t). Such a digital representation can be exploited to detect the presence of a subject. Such detection can be performed by known methods of analysis. By way of non-limiting examples, the capture means MC may be an image sensor such as a camera. The digital representation R (t) delivered by such a sensor may consist of an array of pixels encoding a shade of gray for each of them. The detection of a subject is therefore performed by known methods of analysis, such as by way of non-limiting example the analysis of the histogram of the image previously captured by the capture means MC.

Alternatively, the capture means MC may be an electromagnetic signal sensor. Such a sensor may, by way of non-limiting example, consist of an antenna translating into data the power of a signal emitted by an electronic object carried by a subject circulating the zone of interest ZI. Such a sensor produces and a digital representation R (t) of the zone of interest ZI in connection with a current period t, consisting of a table comprising the value of a signal power emitted by any captured electronic object. The detection of a subject may thus consist in comparing the value of said captured power with a second predetermined table of standard powers respectively characterizing minimum distances with respect to said threshold.

 Whatever the type of capture means MC chosen, the latter can be directly connected by a wired bus to said processing unit UT. It may alternatively be remote from the processing unit UT and cooperate with said processing unit UT via a wireless link, for example through an Internet network or an intranet. Although FIG. 1 explicitly only describes a single capture means MC, other identical or complementary capture means can also be connected directly or indirectly to the processing unit UT. The process of detecting a subject may then consist of an analysis of a composite or plural digital representation resulting from the data delivered by different capture means.

In order to be able to estimate a threshold crossing, the processing unit UT advantageously comprises a CPU microcontroller cooperating, by coupling and / or wired bus, with data storage means MM and / or MP programs and with the means MC capture. Such storage means consist essentially of one or more non-volatile memories, such as, for example, an MP memory for recording in particular instructions of a program P which, when they are executed or interpreted by said microcontroller CPU, trigger the implementation of a method for estimating a threshold crossing according to the invention. The storage means may furthermore comprise data memories MM, cooperating with the CPU microcontroller of the processing unit UT, provided for recording the data structures necessary for the implementation of such a method for estimating the crossing of threshold according to the invention. As non-limiting examples, the data can be stored in chained tables or data structures. To facilitate the understanding of the invention, the storage means MP and MU are represented in FIG. 1 as being distinct functional elements. The storage means MP and MU could also constitute one and the same physical resource. In the same way, the processing unit UT could be that of one or more communicating electronic devices cooperating with the capture means MC and the storage means MM and / or MP. As a variant, such an electronic device could communicate with an outsourced server including memory means MM. The role of the processing unit UT of such a system would consist mainly of transmitting the data collected by the capture means MC to said server.

In a preferred example of the invention, but in a nonlimiting manner, data are recorded in one or more structures each comprising one or more records. As an example these recordings may be dedicated or associated with one or more subjects Si and one or more digital representations R (t) of a zone of interest ZI vis-à-vis a threshold. The various structures mentioned above may, in a variant, constitute only one entity and can not constitute any limitation for the invention.

 Each record associated with a digital representation R (t) is arranged to store the data relating to a digital representation during a current period t, such as by way of non-limiting example, a capture identifier p, relative data. at the computer transcription of said digital representation, a value characterizing the time stamp of the current period t, an identifier of the sensor at the origin of the digital representation of the zone of interest ZI during said current period t, etc.

 Each record or data structure associated with a subject Si may be arranged to store data necessary for the threshold crossing estimation of said subject Si, such as by way of nonlimiting examples a subject identifier ISi, a minimum distance di (t) of the subject Si with respect to the threshold SP during a current period t and a minimum distance di (tl) of said subject Si with respect to the threshold during a preceding period. A record associated with a subject Si may further comprise a field recording the value of the minimum distance di (t) estimated during the current period t.

In addition, the memory means MM advantageously comprise a predetermined distance d _seu ii characterizing the width of the narrow observation band ZIP. By way of non-limiting example, this distance may be equal to thirty centimeters. At the end of the implementation of a threshold crossing estimation method according to the invention, as described later by way of nonlimiting example in connection with FIG. 2, the memory means MM comprise in addition data characterizing a threshold crossing estimated by the subject from or to the zone of interest ZI, data not shown by simplification measure in FIG.

FIG. 2 depicts a block diagram according to the invention of a method 100 for estimating the crossing of a threshold.

 The method 100 may be implemented iteratively and continuously, as by way of non-limiting example, every five hundred milliseconds. The implementation of the method 100 may, in a variant, be activated in response to a triggering event, such as, by way of non-limiting example, the detection by a presence detection sensor, for example of the infrared type, of a subject in the area of interest ZI. In this second case, the method 100 may be iteratively implemented for a given period of time or interrupted after a given second period during which no subject presence has been detected.

To illustrate the contribution of the invention, let us study a first exploitation case according to which a person, or more generally a subject Si, is about to cross a threshold SP from a zone of interest ZI towards a zone ZA home as described in connection with Figure 3.

 In connection with FIG. 2, a method 100, in accordance with the invention, implemented by a processing unit UT of a system for measuring the attendance of a reception zone such as that described in connection with FIG. 1, comprises a first step 102 for triggering the capture of an area of interest ZI situated opposite a threshold SP delimiting the reception areas ZA and of interest ZI by capture means MC. Said step 102 consists in producing a digital representation R (t) of the zone of interest ZI in connection with a current period t. The data characterizing the computer transcription of the digital representation R (t) are stored in a dedicated record within the memory means MM.

The method 100 now comprises a step 103 for analyzing the data of the digital representation R (t), in order to detect the possible presence of a subject Si in the zone of interest ZI. In the case where the capture means MC consist of an image sensor, such a step may consist of analyzing the digital representation of the pixels constituting said captured image and concluding according to known methods of image analysis with the presence or the absence of a subject in the zone of interest ZI. In a variant, the capture means MC may consist of an antenna capable of detecting an electromagnetic field emitted by a communicating electronic device carried by a subject circulating in the area of interest ZI. The analysis of the representation R (t) could attest to the presence of a subject if the capture means MC detects a signal transmitted by a communicating electronic device, for example, a signal transmitted by a proximity communication protocol such as Bluetooth or ZigBee. Step 103 may also include, in a record dedicated to the digital representation R (t) of the memory means MM, an attribute or an indicator attesting to the presence of one or more subjects in the area of interest. ZI or on the contrary, attesting to the absence of such a subject in said zone. Such an attribute may be similar to the current value of a counter of subjects detected in said area. A null value can translate an area of interest ZI blank of any subject or visitor.

 The method 100 comprises a step 104-a for estimating a minimum distance di (t) separating a detected subject Si from the threshold SP. Such a minimum distance di (t) advantageously corresponds to the length of a segment perpendicular to the threshold SP, whose ends correspond respectively to the threshold and to the position of the subject Si. Step 104 then consists in assigning a value to the minimum distance di (t) of the subject If compared to the threshold during a current period t. Said value is written in a record associated with the subject Si within the memory means MM.

As a variant, said estimated minimum distance di (t) may correspond to a fixed predetermined value or indicator characterizing the presence of said subject Si in the zone of interest ZI, or in the zone of near interest ZIP. Such a predetermined value may, by way of nonlimiting example, be equal to a first constant characterizing the depth of the zone of interest ZI when the presence of a subject is detected in step 103 in said zone of interest ZI, or equal to a second constant characterizing the depth of the zone of interest ZIP near the threshold when the presence of a subject has been detected in said ZIP zone in step 103. If step 103 attests to the absence of a subject Si in the zone of interest ZI, step 104 it may consist in attributing to said minimum distance di (t) a predetermined value d _nd e _f attesting to the absence of a minimum distance estimate. Such a predetermined value may, by way of example, be a constant characterizing an infinite distance or much greater than the depth of the zone ZI.

 The method 100 now comprises a step 104-b consisting in finding and reading, in the recording of the memory means MM dedicated to the subject Si, the values of the minimum distances di (tl) and di (t) respectively estimated during the previous period t-1 and the current period t.

 The method 100 therefore consists in comparing the values of the said minimum distances di (t-1) and di (t).

According to a first situation, said previously read values are both equal to the predetermined value d _nc ie _f attesting to the absence of estimation (situation symbolized by the links 105-n and 109-n of FIG. 2). The treatments then implemented by the method 100 for the current period t are completed. A new iteration of steps 102 to 105 is then triggered for the subsequent period t + 1. Such a situation consists of a persistent absence of subject within the ZI zone.

According to a second situation, the presence of the subject Si is not detected during the current period t. The value of the minimum distance di (t) during the current period t is equal to the predetermined value d _nde f - On the other hand, the presence of said subject Si had been detected during the previous period t-1. The value of the minimum distance di (tl) is, for its part, different from said predetermined value d _nde f (situation symbolized by the links 105-n and 109-y of Figure 2). The method 100 according to the invention then comprises a step 110 for comparing the value of the minimum distance d (t), estimated at the previous time t-1, the value of the predetermined distance d _seu ii characterizing the width of the zone of interest close ZIP of the threshold SP. When said value of the minimum distance di (tl) is less than or equal to said predetermined value d _seu ii (situation symbolized by the link 110-y of FIG. 2), the method comprises a step 111 for estimating a crossing of the threshold of the zone of interest ZI to the reception zone ZA by the subject Si. The latter is considered to have entered said reception zone ZA. This situation is described in FIG. 4a according to which the subject Si has been the subject of a first detection at period t-2, then of a second detection at period t-1 for which the estimated minimum distance di ( tl) was less than the characteristic value d _seu ii and that no presence was detected for the current period t. The method 100 according to the invention can, according to a mode of optional embodiment, include a step for recording in the record dedicated to the subject If within the memory means MM, a data characterizing a threshold crossing from the zone of interest ZI.

According to a third situation, step 110 finds that the minimum distance di (tl) is greater than the value of the predetermined distance d _Seu ii · The current iteration of the process 100 ends for the current period. Indeed, this situation corresponds to a subject S ± whose presence has been detected during the previous period t-1 in the zone of interest ZI outside the zone of near interest ZIP, and which has just left the zone observing without crossing the threshold. Such a subject If has only passed away from the threshold without ever approaching it significantly.

According to a fourth situation, the presence of a subject Si has been detected within the zone ZI. A minimum distance di (t) has been estimated in step 104-b. Di (t) value is different from the predetermined value _n i _e f - The method 100 includes then, a step 108 for comparing the value of the minimum distance d (t) estimated at the predetermined value _seu ii · Such a step 108 estimates that there is a threshold crossing by the subject to the zone of interest ZI, if said value di (t) is lower than the predetermined value d _Seu ii and if the value of the minimum distance di ( tl) of the subject with respect to the threshold is equal to the predetermined value d _ndef (situation symbolized by the link 106-n of Figure 2 and Figure 4b). According to this situation, the presence of a subject Si is detected in the very close ZIP of the SP threshold during the current period, whereas no presence of said subject had been previously detected. In all likelihood, the subject just left the reception area. The method 100 can therefore include a step for writing, in the recording dedicated to the subject Si in the memory means MM, a data characterizing a threshold crossing to the zone of interest ZI.

According to a fifth situation, the minimum value di (t) estimated is greater than the predetermined value d _seu ii, regardless of the value of the minimum distance di (tl). The treatments then implemented by the method 100 for the current period are completed. Such a situation describes a subject moving within the area of interest ZI while remaining outside the near ZIP area of interest. A new iteration of steps 102 to 105 is then triggered for the subsequent period t + 1.

Whatever one of the five situations mentioned above, the method 100 includes a step 107 to replace the estimated value of the minimum distance di (tl) of the subject with respect to the threshold during a preceding period t-1 by the value the minimum distance di (t) of the subject with respect to said threshold during the current period t. Step 107 is implemented before any new iteration of steps 102 and subsequent for the next period t + 1. According to a variant of the invention, a method 100 may comprise a step 113 for encoding and triggering the transmission of a status message to a destination. third-party electronic entity in communication with said UT processing unit. Such a status message may advantageously contain a datum characterizing a threshold crossing estimated by a subject from or to the zone of interest ZI, a capture means identifier MC, and an identifier of said third electronic entity. The latter can receive and decode in turn the identifier of capture means MC and the value of the data characterizing a crossing threshold. The electronic entity instantly knows that a subject has just crossed the threshold observed by the MC or means of capture. By way of nonlimiting example, the status message can be sent to a third entity such as a communicating electronic device, for example a mobile phone, which receives, decodes and restores the value of the data characterizing a crossing of threshold estimated by the subject from or to the area of interest ZI to the manager of the reception area. Thus, the owner of the mobile phone can know, in real time, the entrances and exits in connection with the reception area he wants to know attendance. According to a variant of the invention, the third entity may consist of a programming interface, "Application Programming Interface" in English, which, after decoding the content of the status message, can interpret the value of the characterizing data. a threshold crossing by a subject from or to the zone of interest ZI and triggering a determined service. Such an interface may consist of a domotic control interface triggering, as a non-limiting example, the ignition or the extinction of light sources and / or heating within the reception area ZA if the value of the data from the status message characterizes an entry or an exit of said reception area.

 According to a variant of the invention, the processing unit UT or a third electronic entity in communication with said processing unit UT can credit a counter accounting for the threshold crossings made by a given subject Si from the area of interest or to the area of interest. By way of example, a value characterizing an output may output said counter by one unit. A value characterizing an entry may credit a unit said counter. Such a counter associated with the timestamp of each crossing makes it possible to compile a log of the attendance of a reception area. In this way, it is possible in particular to know the number of subjects present in said reception area ZA and to control the incoming and outgoing flows in connection with said reception area.

Alternatively or additionally, step 103 of a method 100 according to the invention may, in addition to detecting the presence or absence of a subject, discriminate or distinguish a particular subject among a plurality of subjects whose presence is likely to be detected in the zone of interest ZI. The memory means MM of a system as described in Figure 1, are arranged to include as many records respectively associated with the discriminated subjects. Such a record may include a unique identifier I Si associated with a particular data Psi characterizing a profile or discernable characteristics of the subject Yes . The data Psi may further consist of a data structure comprising the identity of a subject, for example that of the subject Si, as well as the number of accompanying persons authorized to enter a reception area. Said data may further comprise a reception area identifier or a secret operated to allow certain services. Such data Psi may, as non-limiting examples, be previously encoded in the form of a QR-Code or equivalent type of graphic tag, a tag or an electronic tag. Such a graphic tag can be printed on a reservation receipt or presented via the screen of a smartphone. Thus, the invention provides an example of an application according to which such a tag is previously encoded and made available to a subject having reserved a dwelling for example. Upon arrival in the immediate vicinity of the threshold, such subject Si may present the reservation tag to an optical sensor or an electronic antenna cooperating with the processing unit UT of a system according to the invention. Such a sensor or antenna may correspond to the capture means MC having produced the digital representation R (t) or be different means. Step 103 of a method 100 may thus consist of reading and decoding the graphic and / or electronic tag. The data Psi is thus written in the record associated with the subject Si conveying said tag. Steps 106 to 111, consisting in estimating and comparing minimum distances di (t) and di (tl) for the current period t and the preceding period t-1, are performed for each subject Si discriminated in step 103. It It is therefore possible to estimate, count, one or more crossings exercised by a particular subject compared to those made by other subjects.

A method 100 according to the invention may advantageously comprise a preliminary step 101 for parameterizing the operation of the processing unit UT and / or for initializing the content of the storage means MM and / or MP. Such an initialization can consist in loading, within the memory MP, the instructions of a program P which, when they are executed or interpreted by said microcontroller CPU, trigger the implementation of a method 100 to estimate the crossing. threshold according to the invention. Such an initialization may, in addition, consist in assigning to the minimum distances di (tl) the predetermined value d _nd e _f characterizing a lack of estimation, if the current period t corresponds to the first iteration of said method.

Claims

A method (100) for estimating a threshold crossing by a subject (Si), said method being implemented by a processing unit (UT) cooperating with one or more capture means (MC) of an area of interest ( ZI) facing said threshold (SP) and producing a digital representation (R (t)) of said zone for a given period (t), and storage means (MM), the storage means ( MM) recording said digital representation (R (t)), said method (100) comprising:  a step (102) for triggering the capture of the area of interest (ZI) and producing a digital representation (R (t)) of said zone of interest for the current period (t);  a step (103) for analyzing said digital representation (R (t)) and detecting the presence of a subject in the area of interest (ZI) or attesting to the absence of a subject in said area of interest (ZI); and being characterized in that the storage means (MM) stores the value of a minimum distance (di (tl)) of the subject with respect to a threshold estimated during a preceding period (t-1), and in that that it comprises: a step for estimating (104-a) a minimum distance (d ± (t)) of the subject by referred to the threshold during the current period (t) when the step (103) for analyzing the digital representation (R (t)) detects the presence of the latter in the zone of interest (ZI) or for assigning it a predetermined value (d _nc ief) characterizing a lack of estimation if said step (103) for analyzing the digital representation (R (t)) attests to the absence of said subject; a step (104-b) for reading the value of the minimum distance of the subject from the threshold in the previous period (di (t-1)); a step (111) for estimating a crossing of the threshold of the subject from the area of interest (ZI) if: • (105-n) the value of the minimum distance (d (t)) during the current period is equal to the predetermined value (d _nc ief) characterizing a lack of estimation, • (109-y) the value of the minimum distance (di (tl)) in the previous period is different from a predetermined value (d _nc ief) attesting to the absence of an estimate, and • (110-y) said estimated value of the minimum distance (di (tl)) of the subject with respect to a threshold during the previous period (t-1) is less than a predetermined distance (d _seu ii) characterizing a narrow band of observation close to the threshold  a step (107) for replacing the estimated value of the minimum distance (di (tl)) of the subject with respect to the threshold during the preceding period (t-1) by the value of the minimum distance (d ± (t) ) during the current period (t). Method (100) according to the preceding claim, comprising a step (108) subsequent to the step (104-b) to read the value of the minimum distance of the subject from the threshold in the previous period (di (tl)) , to compare the value of the minimum distance (d (t)) of the subject with respect to the threshold during the current period (t) to the predetermined distance (d _seu ii) characterizing a narrow observation band close to the threshold and for estimate a threshold crossing of the subject to the zone of interest (ZI) if:  (105-y) the value of the minimum distance (d (t)) in the current period is different from the predetermined value (dndef) indicating the absence of an estimate, (106-n) the value of the minimum distance (di (tl)) estimated during a period preceding is equal to a predetermined value (d _nc ief) attesting to the absence of an estimate, and the value of the estimated minimum distance (di (t)) of the subject with respect to the threshold during the current period (t) is less than the value of the predetermined distance (d _S euii) characterizing a close close observation band threshold. A process (100) according to any one of the preceding claims, wherein  the storage means (MM) comprise one or more records respectively associated with one or more subjects (Si) comprising a subject identifier (ISi), the value of a minimum distance (di (tl)) of the subject with respect to a threshold estimated in a previous period (t-1);  the step (103) of analyzing the digital representation (R (t)) of the area of interest during a current period (t) and detecting the presence of a subject (Si), furthermore consists in identifying said subject; the step (104-b) of reading the value of the minimum distance of the identified subject from the threshold during the preceding period (di (tl)) consists in reading the record associated with said identified subject (Si). A method (100) according to any one of the preceding claims, comprising a step (113) for encoding and initiating the transmission of a data message to a third electronic entity in communication with said UT processing unit, comprising data representing an estimated threshold crossing by the subject during the current period (t) from or to the area of interest (ZI). A method (100) according to any one of the preceding claims, comprising a step (113) for crediting a counter accounting for the threshold crossings by the subject from (111) the area of interest (ZI) or to (108) the area of interest (ZI). Computer program product (P) comprising program instructions operable by a processing unit (UT) cooperating with one or more capture means (MC) of a zone of interest (ZI) opposite the 'a threshold and production of a digital representation (R (t)) of said zone, and storage means (MM), the memory means (MM) recording said digital representation (R (t)) and the value of a minimum distance (d ± (t)) of the subject with respect to a threshold, which, when executed or interpreted by said processing unit (UT), trigger the implementation of a method for estimating a threshold crossing according to any one of claims 1 to 5. 7. Electronic device comprising a processing unit (UT) cooperating with capture means (MC) and storage means (MM, MP), said electronic device being characterized in that it comprises in the storage means (MM) ) instructions of a computer program product according to the preceding claim. A system for measuring the attendance of a reception zone (ZA), comprising an electronic device according to the preceding claim, cooperating with one or more capture means (MC) of a zone of interest (ZI) facing a -vis a threshold (SP) and production of a digital representation (R (t)) of said zone for a given period (t), and storage means (MM), the storage means (MM) registering said digital representation (R (t)).