TWI761047B - Method for verifying detection range of image detector - Google Patents

Abstract

A method for verifying detection range of image detector verifies a detection range of an image detector by moving an object laterally in a special way.

Description

Method for detecting detection range of image detector

The present invention relates to a detection method, in particular, to a method for detecting the detection range of an image detector.

Visual image detection technology (Video Image Detection) can analyze images. By setting the process and results of image analysis, various event trigger settings can be performed for various moving objects to achieve the effect of early warning. In order to get the best early warning effect, researchers are all committed to developing faster or more accurate image analysis techniques.

As we all know, images must be obtained before image analysis, so the range that can achieve the warning effect is the detection range of the image detector, so how to ensure that the detection range of the image detector can cover the preset area is also very important. of. However, compared with the development of the mainstream image analysis technology, the technology of how to accurately and quickly judge the actual detection range of the image detector is still lacking. It takes a lot of manpower and time to complete the confirmation of the actual detection range of the image detector through operations such as measurement and measurement.

In view of this, an object of the present invention is to provide a method for detecting the detection range of an image detector, which can automate the detection operation to accurately determine the detection range of the image detector.

From one perspective, the description of the present invention provides a method for detecting the detection range of an image detector, which is suitable for detecting the detection status of the target object located on a plane area by the image detector, wherein, The plane region includes a reference line extending along the first axis, and the regions of the plane region located on both sides of the reference line are respectively defined as a first plane region and a second plane region, and the first plane region and the second plane region respectively include the same A plurality of rectangular areas of size, the adjacent two sides of each rectangular area extend along the first axis and the second axis respectively, the length of each rectangular area extending along the first axis is the detection interval length and along the second axis The side length of the shaft extension is the step length, the front of the image detector faces the reference line to capture the plane area, and the minimum distance of each movement of the target is equal to the step length. The method includes: setting the content of the true and false values of the previous detection; moving the target to a first vertex in a rectangular area located on the reference line; moving the target from the first vertex to the first direction along the second axis until the image The detector does not detect the target during the initial judgment period when the target object continuously moves a certain preset distance, and takes the position of the target object at the beginning of the initial judgment period as the initial judgment boundary point; set the detection end distance , wherein the detection end distance is greater than the step length and less than the distance between the initial judgment boundary point and the reference line; and, after obtaining the initial judgment boundary point, the target object is moved to and fro along the second axis for multiple times To determine the detection boundary detection position of the image detector. Among them, each reciprocating movement includes: taking the current position of the target as the starting point of a single reciprocation, and obtaining the result of whether the image detector can detect the target at this time as the authenticity value of this detection; The true and false values of the detection are the same as those of the previous detection, and the moving direction of the set target remains unchanged; when the true and false values of this detection are different from those of the previous detection and the detection end distance is greater than the step length , reverse the moving direction of the target; when the true and false values of the current detection are different from those of the previous detection and the detection end distance is not greater than the step length, stop continuing to make the target move along the second axis for multiple times. Move back and forth each time, and output the area within a step length before the target object reaches the starting point of this single reciprocation as the detection boundary verification position of the image detector; greater than the detection end distance and not less than the step length; and, move the target from the starting point of a single reciprocation by the current reciprocating distance to reach the single reciprocating end point, and change the detection end distance to make the detection end distance equal to the current reciprocating distance , and change the authenticity value of the previous detection so that the authenticity value of the previous detection is equal to the authenticity value of the current detection.

In one embodiment, the aforementioned preset distance is 2Y, and Y is the step length.

In one embodiment, after the target object moves in the first direction along the second axis until the image detector does not detect the target object within the initial judgment period during which the target object continuously moves the preset distance, the target object is further moved. Continue to move in the first direction to the turning point at the first preset distance from the initial judgment boundary point.

，其中，k為第一預設數值，Y為步進長度。 In one embodiment, the above-mentioned first preset distance is

, where k is the first preset value, and Y is the step length.

，其中，a為在執行當次往復移動之前已經執行的往復移動的次數。 In one embodiment, when setting the current reciprocating distance, the current reciprocating distance is set as

, where a is the number of reciprocating movements performed before the current reciprocating movement.

In one embodiment, the size of the target is scaled down from a preset standard.

To sum up, the method for detecting the detection range of the image detector provided by the description of the present invention can make the target move in a specially designed way, and cooperate with the detection of the image detector in the process of moving the target. result to change its direction of movement. Further, since most of the objects move at the edge of the detection range, the detection time spent in other positions can be reduced. Therefore, by using the technology provided in this description, the effect of automatically detecting the detection range of the image detector can be achieved, and the labor and time consumption can be effectively reduced.

Please refer to FIG. 1 , which is a schematic diagram of a detection plane for implementing a method for detecting a detection range of an image detector according to an embodiment of the present invention. As shown in the figure, when the detection range of the image detector 100 is to be detected, the image detector 100 is placed near the detection plane 10 and faces the detection plane 10, and the detection object of the image detector 100 Then, various movements are performed on the detection plane 10 for detection by the image detector 100 . In the present embodiment, the reference line 120 extends along the axis 12 (hereinafter also referred to as the first axis), and the front of the image detector 100 faces the reference line 120 to photograph the plane area 10 and the object moving thereon; the plane area 10 is defined as the left half plane area 11 (also referred to as the first plane area hereinafter) and the right half plane area 13 (hereinafter also referred to as the second plane area), the left half plane area 11 and the right half plane area bounded by the reference line 120 The planar area 13 includes a plurality of rectangular areas having the same size, for example, rectangular areas 110 and 112 . The adjacent two sides of each rectangular area extend along the axis 12 and the axis 14 (hereinafter also referred to as the second axis) respectively, and the length of each rectangular area extending along the axis 12 is the detection interval length D, along the axis The length of the side 14 extends is the step length Y. In order to control the movement of the target easily during detection, the step length Y is set as the minimum moving distance that the target can achieve each time it moves.

Generally speaking, the image detector 100 will have a field of view (Field of View), which is determined by the manufacturing specifications of the image detector 100, and the target object is in this field of view (the field of view shown in the figure). The boundary 100a and the field of view boundary 100b are both visible. However, since the image size of the target object in the image detector 100 changes with the distance between the target object and the image detector 100, when the target object is too far away from the image detector 100, the image Although the detector 100 can "see" the target object, it may not be able to clearly determine that the target object is the pre-set object because the volume of the target object in the image is too small. That is to say, due to the difference of the image analysis software matched with the image detector 100, the range of whether the target object can be identified as a pre-defined object may be different. What the present invention needs to detect is image detection. The device 100 can effectively identify the range of the target after being matched with the image analysis software. For the convenience of explanation, the word "detection" mentioned in this case not only includes the operation of the image detector 100 to obtain the image of the target object, but also includes the operation of judging whether the target object conforms to the pre-defined object.

The method for detecting the detection range of the image detector in an embodiment of the present invention is described below using the flowchart shown in FIG. 2 and FIG. 1 . In order to implement this method, a controller (not shown) can be used to obtain the detection results of the image detector and to control the movement and steering of the target. As shown in FIG. 2 , when starting the detection, the controller will first move the target to a vertex of the rectangular area located on the reference line (hereinafter also referred to as the first vertex), such as the vertex 110a or the vertex of the rectangular area 110 . 110b (step S200). In order to make the subsequent description more concise, the following description will take the vertex 110a as the first vertex. Since the detection operation from each first vertex is similar to the detection operation from the vertex 110a, the detection operation from other first vertexes can also be performed with reference to the following description.

In this embodiment, after moving to the vertex 110a, the controller may control the target to start moving along the axis 14 (the second axis) (step S202). It should be noted here that, since the present invention is for detecting the detection range of the image detector 100 , when the detection range of the image detector 100 in the left half-plane area 11 is to be detected, the target object It should move toward the left side of the drawing along the axis 14; on the contrary, when the detection range of the image detector 100 in the right half-plane area 13 is to be detected, the target object should be along the axis. 14 and move towards the right side of the diagram. The following will take the detection of the left half-plane area 11 as an example for description, so in step S202 , the target moves along the axis 14 toward the left side of the drawing. A similar approach can also be applied to detect the right half-plane area 13, so the description will not be repeated.

As mentioned earlier, the image detector 100 may fail to detect when the target is too far away from the image detector 100 during the movement of the target. Therefore, theoretically, after the target starts to move When the image detector 100 cannot detect the target for the first time, it is determined that this is the detection boundary of the image detector 100 . However, it is necessary to consider that there may be an unrecognizable object caused by the instability of the imaging element of the image detector 100 or the image analysis software. In this embodiment, the image detector 100 is used to continuously detect the object It is determined whether the target object has exceeded the detection boundary of the image detector 100 under the condition that the target object cannot be detected during the moving distance (hereinafter referred to as the initial judgment period). Therefore, in step S204, after the target object starts to move, the controller can determine whether the image detector 100 has been continuously moved within the preset distance according to the detection result of the image detector 100 (that is, during the initial judgment period). ) can not detect the target (step S204). When the judgment result of step S204 is no, the controller can make the target continue to move along the second axis in the existing direction; on the contrary, when the judgment result of step S204 is yes, the controller The position of the object at the beginning of the preliminary judgment period is the preliminary judgment boundary point (step S206 ).

After obtaining the initial judgment boundary point through step S206 , the controller can obtain the true and false values of the previous detection and the detection end distance to facilitate subsequent operations. Among them, the preset value is used when the authenticity value of the previous detection is used for the first time (step S230 ), so as long as the content of the authenticity value of the previous detection is set before the step S208 is performed; similar Yes, the preset value is also used when the detection end distance is taken for the first time (step S240 ), so it is only necessary to set the detection end distance value before proceeding to step S208 . When setting the authenticity value of the previous detection in step S230, it is recommended to set the authenticity value of the previous detection as the result of whether the target object can be detected by the image detector 100 at the first position of the method. . In this embodiment, since the target object is moved to a point on the reference line 120 at the beginning, the controller can set the previous detection result according to the detection result of the target object by the image detector 100 at this time. The content of the true and false values. For example, when the image detector 100 can detect the target located at the first vertex 110a, the controller can set the previous detection authenticity value to be true; and when the image detector 100 cannot detect the position When the first vertex 110a is the target object, the controller can set the value of the previous detection true or false as false. In another embodiment, because a certain point on the reference line 120 is the closest point to the image detector 100 in the straight line extending along the axis 14 passing through this point, when the image detector 100 cannot detect the position at When the target object is on the reference line 120, the controller can directly skip the subsequent steps and move the target object to another position on the reference line 120, and then start to execute the process shown in FIG. 2 again.

Further, it is suggested that the detection end distance set for the first time in step S240 is greater than the minimum moving distance (ie the step length) of the target; in addition, in order to reduce the possibility of errors during automatic operation, in step S240, the detection The ending distance is set to be smaller than the distance between the initial judgment boundary point and the reference line 120 , thereby preventing the object from moving from the left half-plane area 11 to the right half-plane area 13 . Please refer to FIG. 3 together. In other embodiments, in order to ensure that the target object does not move from the left half-plane area 11 to the right half-plane area 13, after the determination result in step S204 is yes, the controller may further make the target The object moves in the original moving direction to the turning point at the first preset distance from the initial judgment boundary point (step S300 ), so that it can be ensured that even if the detection end distance is set to be between the initial judgment boundary point and the reference line 120 distance, the target will not be mistakenly moved to another half-plane area.

Based on the above, after obtaining the first set of the previous detection authenticity value and the detection end distance, the controller can control the target to reciprocate several times along the second axis to determine the detection of the image detector. boundary. In order to make the description clearer, the detection boundary of the image detector detected by the reciprocating movement along the second axis for several times is referred to as the detection boundary detection position.

In this embodiment, each reciprocating movement along the second axis includes steps after step S208. First, the controller can obtain the current position of the target object through the image detector 100 and define it as the starting point of a single reciprocation, and then also obtain from the image detector 100 to indicate whether the image detector 100 can detect at this time. The result of the target object (hereinafter referred to as the authenticity value of the current detection) and the previously set authenticity value of the detection are obtained (step S208 ). Next, the controller determines whether the obtained authenticity value of the current detection is the same as the authenticity value of the previous detection (step S210 ). When the judgment result of step S210 is yes, it means that the previous detection authenticity value and the current detection authenticity value are both true or false, and the controller maintains the moving direction of the target object unchanged (step S214 ). ); on the contrary, when the judgment result of step S210 is no, it means that the previous detected true and false values and the current detected true and false values are one is true and the other is false, at this time the controller will further It is determined whether the detection end distance is greater than the step length (step S212 ). When the judgment result of step S212 is yes, the controller will change the moving direction of the target object to move the target object in the opposite direction along the axis 14 (step S216 ); on the contrary, when the judgment result of step S212 is no, control the The sensor stops and continues to make the target reciprocate along the second axis, and outputs the area within a step length before the target reaches the starting point of the single reciprocation as the detection boundary check position of the image detector 100 ( step S250).

According to the above, after determining the next moving direction of the target through step S214 or step S216 , the controller further sets the current reciprocating moving distance (step S218 ). In order to gradually approach the possible detection boundary detection position, in step S218, it is set that the current reciprocating moving distance should not be greater than the detection end distance. Moreover, since the step length is the minimum distance that the target can move, the current reciprocating distance is set in the current reciprocating distance. You should also move the distance so that it is not less than the step length. Next, after obtaining the current reciprocating distance, the controller can make the target move the current reciprocating distance from the current single reciprocating starting point and according to the previously determined moving direction, thereby reaching the current single reciprocating distance other than the current single reciprocating distance. Points other than the starting point (hereinafter referred to as the single reciprocating end point); and, the controller can also change the detection end distance to make the detection end distance equal to the current reciprocating movement distance set in step S218, and change the previous detection true distance. The false value is set so that the true and false values of the previous detection are equal to the true and false values of the current detection obtained in step S208 (step S220 ).

It should be noted that the current reciprocating distance does not have to be set at the time point of step S218. Those skilled in the art can change the set time according to the conditions required for setting the current reciprocating distance, and such modification does not violate the technical content of the present invention. Another point to note is that since the controller has not executed step S220 when step S208 is executed for the first time, the previous detection authenticity value obtained when step S208 is executed for the first time will be the content set by step S230. ; But after having performed a reciprocating movement, because the previous detection true and false values have been changed by step S220, the content of the previous true and false values obtained by the next step S208 is exactly by the steps in the previous reciprocating movement The content set in S220 is no longer the content set in step S230.

Taking a practical example, the controller may first control the target to move on the reference line 120 and move along the reference line 120 until the image detector 100 can detect the target. Next, the controller may set the position of the target object as the first vertex when the target object is detected for the first time, that is, the corresponding rectangular area is virtually segmented at this time. The following description is based on the following settings: the object is moved from the bottom of FIG. 1 along the reference line 120 toward the image detector 100, and the image detector 100 detects the object when the object reaches the first vertex 110a thing.

，其中，k是一個預設數值，a為在目標物到達第一頂點110a之後且在執行這一次的往復移動之前已經執行的往復移動的次數；在步驟S240設定檢測結束距離的時候可以將檢測結束距離設定為

。當然，k的選擇必須使步驟S240中所設定的檢測結束距離符合前述的規定。進一步的，若搭配圖3所示的實施例來輔助圖2的檢測操作的時候，步驟S300的第一距離可以被設定為

。更進一步的，可以將k設定為2。 After the target object reaches the first vertex 110a, the controller may start the detection operation of the detection boundary of the image detector 100 according to the embodiment shown in FIG. 2 or further in combination with FIG. 3 . Wherein, when the detection operation is carried out according to the embodiment of FIG. 2 , specifically in step S204, it can be determined that the target object cannot be detected by continuously moving a distance of twice the step length (2Y); in step S230 When setting the authenticity value of the previous detection, the authenticity value of the previous detection can be set as true; in step S218, when setting the current reciprocating movement distance, the current reciprocating movement distance can be set as

, where k is a preset value, a is the number of reciprocating movements that have been performed after the target reaches the first vertex 110a and before this reciprocating movement is performed; when the detection end distance is set in step S240, the detection The ending distance is set to

. Of course, k must be selected so that the detection end distance set in step S240 complies with the aforementioned requirements. Further, if the embodiment shown in FIG. 3 is used to assist the detection operation in FIG. 2 , the first distance in step S300 can be set as

. Further, k can be set to 2.

After a corresponding detection boundary check position is obtained through the operation of FIG. 2 , the controller may first move the target object back to the first vertex 110a. After this, the controller may choose to execute the process of FIG. 2 along the axis 14 from the first vertex 110a to the direction of the undetected boundary to obtain another detection boundary detection position. For example, when the target object reaches the first vertex 110a, the left half-plane area 11 is detected by the aforementioned detection method to obtain a corresponding detection boundary detection position, then after the target object returns to the first vertex 110a, the controller The same detection method can be used to detect the right half-plane area 13 to obtain another corresponding detection boundary detection position. In another embodiment, after the target object returns to the first vertex 110a, the controller may move the target object to another first vertex 110b and execute the detection method to obtain another corresponding detection boundary detection position, and in the After the detection boundary detection position of a certain half-plane area is completely detected, the detection boundary detection position of the other half-plane area is started to be detected.

After all the detection boundary check positions are confirmed, the peripheral connections of these detection boundary check positions can define the image detection boundary of the image detector 100 and at the same time define the image detection boundary of the image detector 100 measurement range.

It is worth mentioning that, in any embodiment, when it is necessary to determine whether the image detector 100 detects a target, the target can be controlled to rotate at least once, thereby reducing the aforementioned problems caused by the image detector 100 . The possibility of erroneous identification results due to the instability of the imaging element or image analysis software.

Finally, as mentioned above, since the image size of the target object in the image detector 100 changes with the distance between the target object and the image detector 100, in addition to the above operations, you can also use the By reducing the size of the target from a preset standard according to a certain ratio, the effect of the target being far away from the image detector 100 on the image size is simulated. With the assistance of the size reduction technology, the technology provided by the above content can complete the automatic detection operation of the detection range in a small space.

According to the above description, the method for detecting the detection range of the image detector provided by the description of the present invention can make the target object move in a specially designed way, and cooperate with the detection of the image detector in the process of moving the target object result to change its direction of movement. Further, since most of the objects move at the edge of the detection range, the detection time spent in other positions can be reduced. Therefore, by using the technology provided in this description, the effect of automatically detecting the detection range of the image detector can be achieved, and the labor and time consumption can be effectively reduced.

10: Detection plane 11: Left half area 12, 14: Shaft 13: Right half area 100: Image detector 100a, 100b: Field of view boundary 110, 112: Rectangular area 110a, 110b: Vertices 120: Baseline D: Detection interval length S200-S250: Implementation steps of an embodiment of the present invention S300: a step between step S204 and step S206 in an embodiment of the present invention Y: step length

1 is a schematic diagram of a detection plane for implementing a method for detecting a detection range of an image detector according to an embodiment of the present invention. 2 is a flowchart of a method for detecting a detection range of an image detector according to an embodiment of the present invention. 3 is a flowchart of a method for detecting a detection range of an image detector according to another embodiment of the present invention between steps S204 and S206.

S200~S250: implementation steps of an embodiment of the present invention

Claims (6)

A method for detecting the detection range of an image detector, suitable for detecting the detection status of an image detector for a target located on a plane area, the plane area including a reference extending along a first axis line, the areas of the plane area on both sides of the reference line are respectively defined as a first plane area and a second plane area, and the first plane area and the second plane area respectively include a plurality of rectangular areas of the same size, Adjacent two sides of each of the rectangular regions extend along the first axis and a second axis, respectively, and a side length of each of the rectangular regions along the first axis is a detection interval length and along the first axis The side length extended by the second axis is a step length. The image detector faces the reference line to photograph the plane area. The minimum distance each time the object moves is equal to the step length. The method is characterized by comprising: Set the content of the previous detection authenticity value; moving the target to a first vertex where one of the rectangular areas is located on the reference line; Move the target object along the second axis to a first direction until the image detector does not detect the target object within a preliminary judgment period when the target object continuously moves a predetermined distance, and use The position of the target at the beginning of the preliminary judgment period is a preliminary judgment boundary point; Setting a detection end distance, wherein the detection end distance is greater than the step length and smaller than the distance between the initial judgment boundary point and the reference line; and After the initial judgment boundary point is obtained, the target object is moved back and forth along the second axis multiple times to determine a detection boundary check position of the image detector, wherein each back and forth movement includes: Taking the current position of the target as the starting point of a single reciprocation, and obtaining the result of whether the image detector can detect the target at this time is a true or false value of this detection; When the authenticity value of the current detection is the same as the authenticity value of the previous detection, the moving direction of the target object is set to remain unchanged; When the current detection authenticity value is different from the previous detection authenticity value and the detection end distance is greater than the step length, reversely change the moving direction of the target object; When the true and false values of the current detection are different from the true and false values of the previous detection, and the detection end distance is not greater than the step length, stop continuing to make the target object move back and forth along the second axis for multiple times, And output an area within the step length before the target object reaches the starting point of the single reciprocation as the detection boundary check position; Setting a current reciprocating distance, the current reciprocating distance is not greater than the detection end distance and not less than the step length; and Make the target move the current reciprocating distance from the single reciprocating starting point to reach a single reciprocating end point, and change the detection end distance to make the detection end distance equal to the current reciprocating distance, and change the previous detection true The false value is set so that the previously detected true and false value is equal to the current detected true and false value. The method of claim 1, wherein the preset distance is 2Y, and Y is the step length. The method of claim 1, wherein the target object moves to the first direction along the second axis until the image detector continues to move the target object by the predetermined distance during the initial determination period. After the target object is not detected, the target object is further moved in the first direction to a turning point which is a first preset distance from the initial judgment boundary point. The method of claim 3, wherein the first preset distance is

, k is a first preset value, Y is the step length. The method according to claim 4, wherein when setting the current reciprocating distance includes: setting the current reciprocating distance as

, a is the number of reciprocating movements that have been performed before the current reciprocating movement. The method of claim 1, wherein the size of the target is scaled down from a predetermined standard.

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