Patent Publication Number: US-2022237886-A1

Title: Reading system, moving body, reading method, and storage medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-098633, filed on May 27, 2019; the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a reading system, a moving body, a reading method, and a storage medium. 
     BACKGROUND 
     There is a system that reads a value (an indication) of a meter. It is desirable to increase the reliability of the indication read by the reading system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a functional configuration of a reading system according to a first embodiment; 
         FIG. 2A  to  FIG. 2D  are schematic views illustrating meters; 
         FIG. 3A  and  FIG. 3B ,  FIG. 4A  to  FIG. 4C ,  FIG. 5A  and  FIG. 5B ,  FIG. 6 , and  FIG. 7A  to  FIG. 7D  are figures for describing processing according to the reading system according to the first embodiment; 
         FIG. 8  is a flowchart illustrating the processing according to the reading system according to the first embodiment; 
         FIG. 9  is a block diagram illustrating a configuration of a reading system according to a second embodiment; 
         FIG. 10  is a block diagram illustrating a configuration of another reading system according to a third embodiment; and  FIG. 11  is a schematic view describing an operation of the reading system according to the third embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     According to an embodiment, a reading system includes a first extractor and a reader. The first extractor extracts, from an image in which a meter is imaged, a first region surrounded with a first contour, and a second region surrounded with a second contour positioned outward of the first contour. The reader calculates a first indication based on the first region, calculates a second indication based on the second region, calculates a first score relating to the first indication based on the first region, and calculates a second score relating to the second indication based on the second region. 
     Various embodiments are described below with reference to the accompanying drawings. 
     In the specification and drawings, components similar to those described previously are marked with the same reference numerals, and a detailed description is omitted as appropriate. 
     First Embodiment 
       FIG. 1  is a block diagram illustrating a functional configuration of a reading system according to a first embodiment. 
       FIG. 2A  to  FIG. 2D  are schematic views illustrating meters. 
       FIG. 3A ,  FIG. 3B ,  FIG. 4A  to  FIG. 4C ,  FIG. 5A ,  FIG. 5B ,  FIG. 6 , and  FIG. 7A  to  FIG. 7D  are figures for describing processing according to the reading system according to the first embodiment. 
     The reading system  1  is used to read a value (an indication) of a meter from an image including the meter. The type of the object meter is arbitrary. For example, the reading system  1  may be used to read the indications of round meters M 1  and M 2  such as those illustrated in  FIG. 2A  and  FIG. 2B . A round meter includes a pointer In rotating with some point as the center, multiple graduations Sc marked around the center point, numerals Nu marked to correspond to at least a portion of the multiple graduations Sc. The graduations Sc are arranged in a circular configuration or a circular arc-like configuration. The round meter shows a value by the pointer In indicating a designated graduation Sc by one of the pointer In or the graduations Sc rotating along the arrangement direction of the graduations Sc. 
     The reading system  1  also can be used to read the indication of a vertical meter M 3  such as that illustrated in  FIG. 2C  or a horizontal meter M 4  such as that illustrated in  FIG. 2D . Vertical meters and horizontal meters include the pointer In, the multiple graduations Sc arranged in one direction, and the numerals Nu marked to correspond to at least a portion of the multiple graduations Sc. Vertical meters and horizontal meters show a value by the pointer In indicating a designated graduation Sc by one of the pointer In or the graduations Sc moving along the arrangement direction of the graduations Sc. 
     As illustrated in  FIG. 1 , the reading system  1  according to the first embodiment includes a processing device  10 . The processing device  10  includes an acceptor  11 , a first extractor  12 , a corrector  13 , a second extractor  14 , a reader  15 , and an outputter  16 . 
     For example, an external imaging device acquires a static image by imaging the meter. The imaging device transmits the image in which the meter is imaged to the processing device  10 . Or, the imaging device may store the image in a memory device  20 . The processing device  10  may acquire the image by accessing the memory device  20 . A video image may be imaged by the imaging device. For example, the imaging device cuts out a static image from the video image and transmits the static image to the processing device  10  or the memory device  20 . An object other than the meter may be imaged in the image. 
     The acceptor  11  accepts the image input to the processing device  10 . The acceptor  11  outputs the image to the first extractor  12 .  FIG. 3A  is an example of the image input to the processing device  10 . 
     From the input image, the first extractor  12  extracts a region including the graduations, the numerals, and the pointer of the meter. As one specific example, the first extractor  12  includes a contour extractor  12   a , a contour selector  12   b , and a determiner  12   c.    
     For example, the contour extractor  12   a  extracts contours (edges) included in the input image based on the brightness difference or the luminance difference of the input image. The contour extractor  12   a  also may perform processing of the input image as appropriate when extracting the contour. For example, the contour extractor  12   a  may convert the input image into grayscale, subsequently binarize the image, and extract the contours from the binary image. 
     The contour selector  12   b  selects a portion of the contours from the multiple contours that are extracted. For example, the contour selector  12   b  compares the maximum length in some one direction and the surface area to preset thresholds for the regions surrounded with the contours. The contour selector  12   b  selects the regions for which the maximum length and the surface area respectively are greater than the thresholds. Thereby, the regions that have surface areas that are too small, regions having shapes much different from a meter, etc., are excluded. For example, multiple contours are extracted from the input image illustrated in  FIG. 3A , and contours e 1  and e 2  illustrated in  FIG. 3B  are selected from the multiple contours. 
     The determiner  12   c  determines the contours of the meter to which the contours of the selected regions correspond. For example, an inner contour E 1  that surrounds a display panel and a contour E 2  outward of the contour E 1  exist in each of the meters illustrated in  FIG. 2A  to  FIG. 2D . From the selected contours, the determiner  12   c  determines a first contour corresponding to the contour E 1  and a second contour corresponding to the contour E 2 . 
     For example, as illustrated in  FIG. 4A , the determiner  12   c  sets two regions r 1  and r 2  for each contour e that is selected. The region r 1  is positioned inward of the contour e. The region r 2  is positioned outward of the contour e. The shapes of the regions r 1  and r 2  can be modified appropriately according to the meter to be read. As an example, the region r 1  and the region r 2  are set along the contour e. Widths w 1  and w 2  of the regions are determined according to the size of the contour e. For example, the proportion of the width w 1  to the size of the contour e and the proportion of the width w 2  to the size of the contour e are prestored in the memory device  20 . 
     The determiner  12   c  determines the relationship between the luminance of the region r 1  and the luminance in the region r 2  for each contour e. For example, the determiner  12   c  determines which of the average value of the luminance in the region r 1  and the average value of the luminance in the region r 2  is greater. When the surface areas of the region r 1  and the region r 2  are equal, the determiner  12   c  may determine which of the total value of the luminance in the region r 1  and the total value of the luminance in the region r 2  is greater. 
     A first relationship of the luminance of the region positioned inward of the contour E 1  and the luminance of the region positioned outward of the contour E 1  for the meter to be read is stored in the memory device  20 . Also, a second relationship of the luminance of the region positioned inward of the contour E 2  and the luminance of the region positioned outward of the contour E 2  is stored in the memory device  20 . The determiner  12   c  compares the relationship of the luminances of each contour e to the relationships of the luminances stored in the memory device  20 . The determiner  12   c  determines the contour e having a relationship of the luminances matching the first relationship to be the first contour. The determiner  12   c  determines another contour e having a relationship of the luminances matching the second relationship to be the second contour. 
     Typically, the background of the display panel of a meter is a bright color (e.g., white). The outer rim of the meter is a darker color than the display panel. A wall or the like to which the meter is mounted has a brighter color than the outer rim of the meter. In such a case, the first relationship is set so that the luminance of a region R 1  positioned inward of the contour E 1  is greater than the luminance of a region R 2  positioned outward of the contour E 1  as illustrated in  FIG. 4B . The second relationship is set so that the luminance of a region R 3  positioned inward of the contour E 2  is less than the luminance of a region R 4  positioned outward of the contour E 2  as illustrated in  FIG. 4C . 
     The contours E 1  and E 2  may be contours other than the contour of the display panel and the contour of the meter. For example, a contour other than the display panel and the meter may be extracted as a result of the image processing due to a difference of the color, the shape, or the reflectance between the portions of the meter. The contour that is extracted may be used as a contour corresponding to the meter. In such a case, the relationship between the luminance of the region positioned inward of the contour and the luminance of the region positioned outward of the contour is stored in the memory device  20 . 
     For example, the contour E 1  of the display panel and the contour E 2  of the meter exist in the meter illustrated in  FIG. 3A . On the other hand, as a result of the contour extraction by the image processing, the contour e 1  is extracted between a contour e 0  corresponding to the contour E 1  and the contour e 2  corresponding to the contour E 2  as illustrated in  FIG. 3B . The contour e 1  is extracted due to the shape of the outer rim of the meter. An outer rim OP of the meter illustrated in  FIG. 3A  is rounded, and the reflection amounts of the light inward of the outer rim and outward of the outer rim are different. As a result, the contour e 1  is extracted at substantially the center of the outer rim OP. The following processing may be performed by using the contour e 1  as the first contour corresponding to the meter. 
     The determiner  12   c  extracts, from the input image, a first region that is surrounded with the first contour satisfying the first relationship, and a second region that is surrounded with the second contour satisfying the second relationship. As an example, the first region includes the display panel of the meter. The second region includes the display panel and the outer rim of the meter. 
     The corrector  13  performs projective transformations of the first region and the second region as appropriate. Typically, the contour of the meter or the contour of the display panel of the meter is circular or quadrilateral. When the first contour or the second contour is trapezoidal, parallelogram-shaped, etc., the corrector  13  performs projective transformation of the first region or the second region so that the first contour or the second contour is rectangular. When the first contour or the second contour is elliptical or oval, the corrector  13  performs projective transformation of the first region or the second region so that the first contour or the second contour is circular. Distortion of the first region or the second region is corrected by the projective transformation. The corrector  13  outputs the corrected first region and the corrected second region to the second extractor  14 . 
     The second extractor  14  extracts a first scale region and a first numeral region from the first region. Also, the second extractor  14  extracts a second scale region and a second numeral region from the second region. For example, the positions and the sizes of the first scale region and the first numeral region are determined based on the first region. The positions and the sizes of the second scale region and the second numeral region are determined based on the second region. The relationship between the first scale region and the first numeral region for the first region and the relationship between the second scale region and the second numeral region for the second region are prestored in the memory device  20 . The second extractor  14  outputs the first scale region, the first numeral region, the second scale region, and the second numeral region to the reader  15 . 
     The reader  15  calculates a first indication based on the first region and calculates a second indication based on the second region. Also, the reader  15  calculates a first score relating to the first indication based on the first region, and calculates a second score relating to the second indication based on the second region. 
     Specifically, the reader  15  includes a recognizer  15   a , a graduation joiner  15   b , an indication calculator  15   c , a score calculator  15   d , and an indication selector  15   e.    
     The recognizer  15   a  recognizes multiple graduations marked in the display panel from the luminance difference in the scale region. The recognizer  15   a  recognizes multiple numerals marked in the display panel in the numeral region. For example, the recognizer  15   a  designates the numerals by cutting out the numerals from the display panel one at a time and comparing the cut-out numeral and preregistered numerals. The recognizer  15   a  recognizes the position and the angle of the pointer from the luminance distribution in the numeral region. The recognizer  15   a  may recognize the position and the angle of the pointer from the luminance distributions in the numeral region and the scale region. The recognizer  15   a  also may recognize the shape of the pointer. 
     When the meter to be read is round, the recognizer  15   a  may perform polar transformations of the scale region and the numeral region. For example, the recognizer  15   a  recognizes the graduations and the pointer from the scale region and the numeral region having undergone the polar transformations, and recognizes the numerals from the numeral region that has not undergone a polar transformation. 
       FIG. 5A  illustrates a first scale region Sr 1  and a first numeral region Nr 1  set based on the first contour e 1 . For example, as illustrated in  FIG. 5A , multiple graduations Sc 1  (a first graduation group) and a pointer In 1  (a first pointer) are recognized based on the first scale region Sr 1  and the first numeral region Nr 1 . Also, multiple numerals (a first numeral group) are recognized based on the first numeral region Nr 1 . 
       FIG. 5B  illustrates a second scale region Sr 2  and a second numeral region Nr 2  set based on the second contour e 2 . For example, as illustrated in  FIG. 5B , multiple graduations Sc 2  (a second graduation group) and a pointer In 2  (a second pointer) are recognized based on the second scale region Sr 2  and the second numeral region Nr 2 . Also, multiple numerals (a second numeral group) are recognized based on the second numeral region Nr 2 . 
     In the example, the positions and the sizes of the scale regions and the numeral regions are set based on the extracted contours. Therefore, as illustrated in  FIG. 5B , there are cases where the scale region and the numeral region that are set based on one contour are shifted from the region where the graduations and the numerals actually are marked. As a result, as illustrated in  FIG. 5B , there are cases where the position or the angle of the pointer that is recognized is different from the position or the angle of the actual pointer. However, even in such a case as described below, a more accurate indication can be read based on the scale region and the numeral region set based on another contour. 
     The recognizer  15   a  outputs, to the graduation joiner  15   b , the graduation groups, the numeral groups, and the pointers recognized based on the first region and the second region. 
     As illustrated in  FIG. 6 , the graduation joiner  15   b  stores, as the position Information of the graduations, the angles between a reference line G and straight lines SL along which the graduations Sc extend. The graduation joiner  15   b  determines the graduations Sc corresponding to the recognized numerals. 
     The indication calculator  15   c  calculates the indication of the meter based on the angles of the graduations, the correspondence information of the graduations and the numerals, and the angle of the pointer for each of the first region and the second region. The first indication based on the first region and the second indication based on the second region are calculated thereby. 
     The score calculator  15   d  calculates the first score relating to the first indication and the second score relating to the second indication. The first score and the second score respectively show the sureness of the first indication and the sureness of the second indication. For example, the score calculator  15   d  calculates the first score by using the first graduation group, the first numeral group, or the first pointer. The score calculator  15   d  calculates the second score by using the second graduation group, the second numeral group, or the second pointer. 
     In the example described below, the score is calculated to be higher as the goodness of the image increases and the indication has a higher likelihood of being read correctly. A higher score indicates that the reliability of the Indication that is read is high. For example, a good image refers to a state in which the contours are clear because the resolution of the image is sufficiently high, the adhered matter on the meter is low, reflections of light by the meter are low, etc. The score is not limited to the example; the score may be calculated to be lower as the goodness of the character Image increases. In such a case, a lower score indicates that the reliability of the indication that is read is high. 
     A method for calculating the score by using the graduation group is as follows. 
       FIG. 7A  illustrates a scale region Sr and the recognized graduations Sc. In the example, the multiple graduations Sc are arranged in a first direction D 1 , and the graduations Sc extend along a second direction D 2 . The image illustrated in  FIG. 7A  may be an Image obtained by a polar transformation. In such a case, the first direction D 1  corresponds to the circumferential direction, and the second direction D 2  corresponds to the diametrical direction. 
     The score calculator  15   d  calculates the fluctuation of the spacing between the graduations Sc or the fluctuation of the lengths in the second direction D 2  of the graduations Sc. The score calculator  15   d  calculates the score to be higher as the fluctuation decreases. 
     The number of graduations marked on the actual meter may be prestored in the memory device  20 . The score calculator  15   d  may compare the number of the graduations Sc recognized in the scale region Sr to the number of graduations stored in the memory device  20 . The score calculator  15   d  calculates the score to be higher as the difference between the number of the recognized graduations Sc and the number of stored graduations decreases. 
     An image that corresponds to the graduations of the actual meter may be prestored in the memory device  20 .  FIG. 7B  is an example of an image stored in the memory device  20 . The score calculator  15   d  performs pattern matching between the image and the recognition result of the graduations. The score calculator  15   d  calculates the score to be higher as the matching rate increases. 
     The score calculator  15   d  may calculate the score by combining two or more of these methods for calculating the score based on the graduation group. 
     A method for calculating the score by using the numeral group is as follows. 
     The score calculator  15   d  refers to the match rate when the numerals are recognized by the recognizer  15   a . The score calculator  15   d  calculates the score based on the match rate. For example, the score calculator  15   d  averages the match rates of the multiple numerals marked in the display panel and uses the average value as the score. 
     A method for calculating the score by using the pointer is as follows. 
     An image that illustrates the shape of the actual pointer is prestored in the memory device  20 . For example,  FIG. 7C  illustrates the shape of the pointer In that is recognized. The score calculator  15   d  performs pattern matching between the recognized pointer In and the image stored in the memory device  20 . The score calculator  15   d  calculates the score to be higher as the matching rate increases. 
     Or, the score calculator  15   d  may set two regions Ra and Rb as illustrated in  FIG. 7D  with the recognized pointer In as the center. The regions Ra and Rb are arranged in a direction perpendicular to the direction in which the pointer In extends. The score calculator  15   d  compares the luminance in the region Ra and the luminance in the region Rb. The difference between the luminance in the region Ra and the luminance in the region Rb is small when the angle of the recognized pointer In matches the angle of the actual meter shown in the image. The score calculator  15   d  calculates the score to be higher as the difference decreases. 
     The score calculator  15   d  may calculate the score by combining the two methods for calculating based on the pointer described above. 
     The score calculator  15   d  calculates the first score and the second score by the methods described above. The score calculator  15   d  may calculate the score by using two or more of the graduation group, the numeral group, and the pointer. For example, the score calculator  15   d  may calculate the score by combining two or more of the calculation method based on the graduation group, the calculation method based on the numeral group, and the calculation method based on the pointer. The reliability of the score can be increased thereby. 
     The indication selector  15   e  selects one of the first indication or the second indication based on the first score and the second score. For example, the score is calculated to be high when the graduation group, the numeral group, or the pointer is recognized with high accuracy. In such a case, the indication selector  15   e  selects the higher of the first score and the second score. The indication selector  15   e  selects, as the indication of the meter, the indication corresponding to the selected score. 
     Or, a condition that relates to the first score and the second score may be prestored in the memory device  20 . The indication selector  15   e  compares the first score or the second score to the condition. For example, the condition includes a threshold. The threshold may be preset by a user or may be set based on the calculation result of a previous score. When the score is calculated to be high when the recognition accuracy is high, the indication selector  15   e  compares the higher of the first score and the second score to the threshold. When the higher score is not more than the threshold, the processing by the corrector  13  may be re-performed. 
     The corrector  13  re-performs projective transformations of the first region and the second region by using a different condition from the projective transformations of the previous time. Subsequently, the first indication, the second indication, the first score, and the second score are calculated based on the first region of the re-performed projective transformation and the second region of the re-performed projective transformation. Thereby, the indication of the meter can be read with higher accuracy. 
     For example, the processing of the corrector  13  is repeated until the first score or the second score satisfies a condition. Or, the processing of the corrector  13  may be repeated a specified number of times, and the indication that has the highest score may be selected as the indication of the meter. 
     Or, instead of the processing of the corrector  13 , the extraction of the contour by the contour extractor  12   a , the selection of the contour by the contour selector  12   b , the polar transformation by the second extractor  14 , etc., may be re-performed using a different condition from the previous condition. Or, in addition to at least one of such processing, the processing of the corrector  13  may be re-performed using a different condition from the previous condition. 
     The reader  15  transmits the indication of the meter to the outputter  16 . For example, the outputter  16  outputs information based on the indication to an external output device. For example, the information includes the indication that is read. The information may include the result calculated based on the indication that is read. The outputter  16  may calculate another value based on the multiple indications that are read and may output the calculation result. The information also may include the time of the reading, etc. Or, the outputter  16  may output a file including the information such as the indication that is read, the time of the reading, etc., in a prescribed format such as CSV, etc. The outputter  16  may transmit the data to an external server by using FTP (File Transfer Protocol), etc. Or, the outputter  16  may insert the data into an external database server by performing database communication and using ODBC (Open Database Connectivity), etc. 
     The processing device  10  includes, for example, a processing circuit made of a central processing unit. The functions of the acceptor  11 , the first extractor  12 , the corrector  13 , the second extractor  14 , the reader  15 , and the outputter  16  are realized by the processing device  10 . These functions may be realized by multiple processing devices. The memory device  20  includes, for example, at least one of a hard disk drive (HDD), a network-attached hard disk (NAS), an embedded multimedia card (eMMC), a solid-state drive (SSD), or a solid-state hybrid drive (SSHD). The processing device  10  and the memory device  20  are connected by a wired or wireless method. Or, the processing device  10  and the memory device  20  may be connected to each other via a network. 
       FIG. 8  is a flowchart illustrating the processing according to the reading system according to the first embodiment. 
     As illustrated in  FIG. 8 , the acceptor  11  accepts the input image (step S 11 ). The contour extractor  12   a  extracts contours from the input image (step S 12   a ). From the multiple contours that are extracted, the contour selector  12   b  selects a portion of the contours satisfying a condition (step S 12   b ). The determiner  12   c  determines the first contour and the second contour from the selected contour (step S 12   c ). The corrector  13  performs projective transformations and corrections for the first region surrounded with the first contour and the second region surrounded with the second contour (step S 13 ). The second extractor  14  extracts the first scale region and the first numeral region from the first region and extracts the second scale region and the second numeral region from the second region (step S 14 ). 
     The recognizer  15   a  recognizes the first graduation group, the first numeral group, and the first pointer from the first scale region and the first numeral region. The recognizer  15   a  recognizes the second graduation group, the second numeral group, and the second pointer from the second scale region and the second numeral region (step S 15   a ). The graduation joiner  15   b  causes the multiple graduations included in the first graduation group and the multiple numerals included in the first numeral group to correspond to each other. The graduation joiner  15   b  causes the multiple graduations included in the second graduation group and the multiple numerals included in the second numeral group to correspond to each other (step S 15   b ). The indication calculator  15   c  calculates the first indication based on the first region and the second indication based on the second region (step S 15   c ). The score calculator  15   d  calculates the first score by using the first graduation group, the first numeral group, or the first pointer. The score calculator  15   d  calculates the second score by using the second graduation group, the second numeral group, or the second pointer (step S 15   d ). The indication selector  15   e  selects one of the first indication or the second indication based on the first score and the second score. The outputter  16  outputs the selected one of the first indication or the second indication (step S 16 ). 
     Effects of the first embodiment will now be described. 
     When reading the indication of the meter, a method may be considered in which the scale region and the numeral region are extracted based on a designated contour included in the meter. If the designated contour can be detected with high accuracy, the indication of the meter is read with high accuracy by using this method. However, there is a possibility that the designated contour cannot be extracted correctly if other components may be mounted to the meter or if the resolution of the image is low. Also, there is a possibility that the designated contour cannot be extracted correctly if light is reflected by the meter or dirt or the like is adhered to the meter. For example, in the example illustrated in  FIG. 3A  and  FIG. 3B , a cable is connected to the meter, and the outer contour of the meter is not extracted correctly due to the effects of the cable. 
     For this problem, multiple contours that are included in one meter are extracted in the reading system  1  according to the first embodiment. Then, an indication and a score are calculated based on each of the multiple contours that are extracted. For example, the reading accuracy of the indication of the meter can be increased by selecting one of the indications based on the calculated scores. The reliability of the reading system  1  can be increased thereby. 
     Or, the outputter  16  may output the selected one of the first indication or the second indication and one of the first score or the second score relating to the one of the first indication or the second indication. Thereby, the user can ascertain the sureness of the selected indication. For example, even when an abnormal indication that is different from the normal indication is output, the user can confirm the sureness of the indication by referring to the score. 
     The outputter  16  may output at least one of the first indication or the second indication and at least one of the first region or the second region. For example, the outputter  16  outputs the selected one of the first indication or the second indication and one of the first region or the second region where the one of the first indication or the second indication is obtained. Because the Image that is the basis of the selected indication is output, the user easily can ascertain whether or not the indication is correct. 
     In the example described above, one of the first indication or the second indication is selected by the indication selector  15   e . The reading system  1  is not limited to the example; the reading system  1  according to the first embodiment may output the first indication, the second indication, the first score, and the second score. For example, the user determines which of the first indication or the second indication to employ by referring to the first score and the second score. Because the first score and the second score are output, the user can ascertain the sureness of each indication. Or, the user also can confirm whether or not the image used in the reading is appropriate by referring to the first score and the second score. For example, when both the first score and the second score are low, the user may modify the location of the meter, the configuration, the imaging condition of the imaging device, etc., to obtain a more appropriate image. 
     According to the reading system  1  according to the first embodiment, even when only one contour is selected by the contour selector  12   b , the contour of the meter that corresponds to the contour can be determined. Therefore, the scale region and the numeral region can be set more appropriately for the region surrounded with the selected contour. As a result, the indication of the meter can be read with higher accuracy. 
     In the example described above, the reading system  1  calculates two indications (the first and second indications). The reading system  1  is not limited to the example; the reading system  1  may calculate three or more indications based on three or more contours of the meter. In such a case, the reading system  1  calculates three or more scores that relate respectively to the three or more indications. 
     EXAMPLES 
     An example of a method for calculating the score will now be described. 
     The score calculator  15   d  performs pattern matching of the scale region recognized by the recognizer  15   a  and the prestored image of the scale region. For example, the recognized scale region and the image of the scale region are illustrated as binary images. In the binary images, the graduations are illustrated using white, and the background is illustrated using black. The score calculator  15   d  uses the proportion of the number of white pixels included in the recognized scale region to the number of white pixels included in the image of the scale region as a matching rate. The score calculator  15   d  uses the matching rate as the score based on the graduation group. 
     The score calculator  15   d  averages match rates of the recognition of the numerals by the recognizer  15   a  and uses the average value as the score based on the numeral group. 
     The score calculator  15   d  performs pattern matching of the pointer recognized by the recognizer  15   a  and the prestored image of the pointer. The score calculator  15   d  uses the matching rate as the score based on the pointer. 
     The score calculator  15   d  performs the following calculation. 
     
       
      
       S=S 
       1 
       ×W 
       1 
       +S 
       2 
       ×W 
       2 
       +S 
       3 
       ×W 
       3  
      
     
     S 1  is the score calculated based on the graduation group. W 1  is the weight for the score S 1 . S 2  is the score calculated based on the numeral group. W 2  is the weight for the score S 2 . S 3  is the score calculated based on the pointer. W 3  is the weight for the score S 3 . 
     The score calculator  15   d  calculates the score S described above based on each of the first region and the second region and uses the scores S as the first score and the second score. As an example, the weight W 1  is set to 0.7. The weight W 2  is set to 0.5. The weight W 3  is set to 0.2. The first score that is based on the first region surrounded with the first contour e 1  illustrated in  FIG. 5A  is 0.83. The second score that is based on the second region surrounded with the second contour e 2  illustrated in  FIG. 5B  is 0.58. As a result, for example, the indication selector  15   e  selects the first indication corresponding to the first score which is higher. 
     Second Embodiment 
       FIG. 9  is a block diagram illustrating a configuration of a reading system according to a second embodiment. 
     The reading system  2  according to the second embodiment further includes an imaging device  30 . The imaging device  30  generates an image by imaging a meter. The imaging device  30  transmits the generated image to the processing device  10 . Or, the imaging device  30  may store the image in the memory device  20 . The processing device  10  refers to the stored image by accessing the memory device  20 . When the imaging device  30  acquires a video image, the imaging device  30  extracts a static image from the video image and transmits the static image to the processing device  10 . The imaging device  30  includes, for example, a camera. 
     The processing device  10  transmits, to an output device  40 , information based on numerals read from the image that is imaged. The output device  40  outputs the information received from the processing device  10  so that the user can recognize the information. The output device  40  includes, for example, at least one of a monitor, a printer, a projector, or a speaker. 
     For example, the processing device  10 , the memory device  20 , the imaging device  30 , and the output device  40  are connected to each other by a wired or wireless method. Or, these components may be connected to each other via a network. Or, at least two or more of the processing device  10 , the memory device  20 , the imaging device  30 , or the output device  40  may be embedded in one device. For example, the processing device  10  may be embedded integrally with the image processor of the imaging device  30 , etc. 
     Third Embodiment 
       FIG. 10  is a block diagram illustrating a configuration of another reading system according to a third embodiment. 
     The reading system  3  according to the third embodiment further includes a moving body  50 . The moving body  50  moves through a prescribed area. A meter is provided in the area through which the moving body  50  moves. The moving body  50  is, for example, an automatic guided vehicle (AGV). The moving body  50  may be a flying object such as a drone, etc. The moving body  50  may be an independent walking robot. The moving body  50  may be an unmanned forklift, crane, or the like that performs a prescribed operation. 
     For example, the processing device  10  and the imaging device  30  are mounted to the moving body  50 . The processing device  10  may be provided separately from the moving body  50  and may be connected to the moving body  50  via a network. When the moving body  50  moves to a position where the meter is imageable, the imaging device  30  generates an image by imaging the meter. 
     In the processing of the processing device  10 , the meter may be reimaged by the imaging device  30  when the first score or the second score is determined not to satisfy a preset condition. The imaging device  30  reimages the meter using a different condition from the imaging of the previous time. For example, the imaging device  30  reimages the meter by modifying the exposure time, the aperture stop value, or the ISO sensitivity. The position of the moving body  50  may be included in the condition of the imaging. In other words, the imaging device  30  may operate the moving body  50  and image the meter at a different position from the imaging of the previous time. 
     As illustrated in  FIG. 10 , the reading system  3  may further include an acquisition device  60 . The acquisition device  60  is mounted to the moving body  50 . For example, an identifier that includes unique identification information corresponding to the meter is provided. The acquisition device  60  acquires the identification information of the identifier. 
     As illustrated in  FIG. 10 , the reading system  3  may further include a control device  70 . The control device  70  controls the moving body  50 . The moving body  50  moves through the prescribed area based on a command transmitted from the control device  70 . The control device  70  may be mounted to the moving body  50  or may be provided separately from the moving body  50 . The control device  70  includes, for example, a processing circuit made of a central processing unit. One processing circuit may function as both the processing device  10  and the control device  70 . 
     For example, the identifier is a radio frequency (RF) tag including ID Information. The Identifier emits an electromagnetic field or a radio wave including the ID information. The acquisition device  60  acquires the ID information by receiving the electromagnetic field or the radio wave emitted from the identifier. 
     Or, the identifier may be a one-dimensional or two-dimensional barcode. The acquisition device  60  may be a barcode reader. The acquisition device  60  acquires the identification information of the barcode by reading the barcode. 
     As illustrated in  FIG. 10 , the processing device  10  may further include an associator  17 . For example, when acquiring the identification information, the acquisition device  60  transmits the identification information to the processing device  10 . The associator  17  associates the transmitted identification information and the characters that are read. The associated information is stored in the memory device  20 . 
       FIG. 11  is a schematic view describing an operation of the reading system according to the third embodiment. 
     For example, the moving body  50  is a moving body moving along a prescribed trajectory T. The imaging device  30  and the acquisition device  60  are mounted to the moving body  50 . The processing device  10  may be mounted to the moving body  50  or may be provided separately from the moving body  50 . The trajectory T is provided so that the moving body  50  passes in front of meters M 11  and M 12 . 
     For example, the moving body  50  moves along the trajectory T and decelerates or stops when arriving at a position where the meter M 11  or M 12  is imageable by the imaging device  30 . For example, when decelerating or stopping, the moving body  50  transmits an imaging command to the imaging device  30 . Or, the imaging command may be transmitted to the imaging device  30  from the control device  70 . When receiving the command, the imaging device  30  images the meter M 11  or M 12  while the moving body  50  has decelerated or stopped. 
     Or, the moving body  50  moves along the trajectory T at a speed such that the imaging device  30  can image the meter M 11  or M 12  without blur. When the position where the meter M 11  or M 12  is imageable by the imaging device  30  is reached, the imaging command is transmitted from the moving body  50  or the control device recited above. When receiving the command, the imaging device  30  images the meter M 11  or M 12 . When the image has been generated by imaging, the imaging device  30  transmits the image to the processing device  10  mounted to the moving body  50  or provided separately from the moving body  50 . 
     An identifier ID 1  is provided at the meter M 11  vicinity. An identifier ID 2  is provided at the meter M 12  vicinity. For example, the acquisition device  60  acquires the identification information of the identifier ID 1  or ID 2  while the moving body  50  has decelerated or stopped. 
     For example, the moving body  50  moves in front of the meter M 11 . The imaging device  30  generates an image by imaging the meter M 11 . The reading system  1  reads the indication of the meter M 11  from the image. Also, the acquisition device  60  acquires the identification information of the identifier ID 1  corresponding to the meter M 11 . The reading system  1  associates the identification information and the indication of the meter. 
     According to the embodiments described above, the reliability of the indication read from the meter can be increased by using the reading system, the moving body, and the reading method. Similarly, the reliability of the indication read from the meter can be increased by using a program for causing a computer (a processing device) to operate as the acceptor  11 , the first extractor  12 , the corrector  13 , the second extractor  14 , the reader  15 , the outputter  16 , etc. 
     For example, the processing of the various data recited above is executed based on a program (software). For example, the processing of the various information recited above is performed by a computer storing the program and reading the program. 
     The processing of the various information recited above may be recorded in a magnetic disk (a flexible disk, a hard disk, etc.), an optical disk (CD-ROM, CD-R, CD-RW, DVD-ROM, DVD±R, DVD±RW, etc.), semiconductor memory, or another recording medium as a program that can be executed by a computer. 
     For example, the information that is recorded in the recording medium can be read by a computer (or an embedded system). The recording format (the storage format) of the recording medium is arbitrary. For example, the computer reads the program from the recording medium and causes a CPU to execute the instructions recited in the program based on the program. In the computer, the acquisition (or the reading) of the program may be performed via a network. 
     The processing device and the control device according to the embodiments include one or multiple devices (e.g., personal computers, etc.). The processing device and the control device according to the embodiments may include multiple devices connected by a network. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention. The above embodiments can be practiced in combination with each other.