JP2019016027A - Optical numeric character reading method and device - Google Patents

Abstract

To provide an optical numeric character reading method and device which enable accurate reading of numeric characters themselves on a meter even when gradation is formed.SOLUTION: An optical numeric character reading method 1 for imaging, by photographing means, a string of numeric characters displayed on a digital numeric character display unit capable of displaying, for each digit, a numeric character of any of 0 to 9 by a generally 8-shaped structural body composed of four longitudinal side frames and three lateral side frames to read the numeric characters comprises: a side presence/absence numeric character reading step of distinguishing side presence/absence for each of the side frames of the structural body by determining that a side presence/absence state in a side frame as an object subjected to side presence/absence discrimination is the same as a state of either of a side frame in side presence, of side frames other than the discrimination object, or a background in an area near the side frame of the discrimination object, whichever has a color shading level therein nearer that in the side frame as the discrimination object, and repeating the distinguishing for every side frame of the structural body to read the numeric character displayed on the structural body; and a numeric character string reading step of repeating the side presence/absence numeric character reading step for every digit of the string of numeric characters to read the string of numeric characters.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a number reading method and apparatus for photographing and reading a display number of a watt-hour meter that integrates and displays power consumption.

Patent Document 1 discloses an image capturing unit that captures an image of a display unit of an integrated quantity meter, a character recognition unit that recognizes the contents of the display unit captured by the image capturing unit and outputs numerical data, and a record that records the numerical data. And a control unit that activates the imaging unit and the character recognition unit at predetermined time intervals and outputs numeric data from the character recognition unit. The control unit includes the numeric data and the character recognition unit in the recording unit. An automatic meter reading device is disclosed in which the numerical data in the recording unit is updated when it is determined that the numerical data from the character recognition unit is likely by comparing with the numerical data from the character recognition unit.

JP 2000-232032 A

  As described in paragraph [0004] of Cited Document 1, the invention described in Patent Document 1 “photographs the meter indication value optically and recognizes and reads the imaged information as characters by character recognition. In order to solve the problem that there was a possibility of erroneous reading because of the data, as described in paragraph [0020] of cited document 1, “the meter value of the integrated amount meter is , It is judged to be probable if it is larger than the meter value in the recording section and smaller than the sum of the predicted amount when used at the maximum from the previous measurement time to the current measurement time. However, this technique has a problem that it cannot be expected to eliminate the erroneous reading of the captured number itself.

  In addition, although the background area other than the numbers on the meter is the same color, a gradation may be formed by irradiation with light such as lighting or sunlight. If there is a part, the difference in color between the number and the background will be reduced, and if there is no side that constitutes the digital number, it will be misread or if there is no side, it will be misread. Misreads numbers that change numbers depending on the presence or absence of one side, such as “0 and 8”, “8 and 9”, “6 and 8”, “5 and 6”, and “3 and 9”. There was a problem.

The present invention was devised in view of these problems, and it is an object of the present invention to provide an optical number reading method and apparatus capable of accurately reading the meter number itself even if gradation is formed in the background area of the meter. To do.

  The “side frame” used in the present invention is an area in which a digital number string is displayed, and includes four vertical side frames and three horizontal sides of the approximately 8-character structure shown in FIG. This means any one of the side frames a to b, and “side” is the uppermost side of the structure displaying the number 0 in FIG. 5B, for example. This means that the shade level of the color in the side frame is clearly different from the shade level of the background color, for example, the area in the side frame displayed in black. “None” means that the shade level of the color in the side frame is not the same as the background, for example, as shown in FIG. It means the area within the side frame displayed in white. “Background” means an area where a digital number string is displayed but not within a side frame.

The optical number reading method according to claim 1 is a digital number capable of displaying any number from 0 to 9 by a substantially 8-character-shaped structure consisting of a vertical 4 side frame and a horizontal 3 side frame for each digit. An optical number reading method for reading a number string displayed on a display unit by imaging with a photographing unit, and for each side frame of the structure, a color shading level in a target side frame for identifying the presence or absence of a side, State of presence / absence of a side in the side frame of the identification target and the closer one of the color shading level in the side frame of the side frame other than the identification target and the color tone level of the background in the vicinity of the side frame of the identification target Are determined to be the same, the presence / absence of a side is determined, the side presence / absence number reading step of repeatedly performing the side presence / absence determination for all side frames of the component and reading the number displayed on the component, and the side presence / absence number Read the number string by repeating the reading step for all digits of the number string. Characterized in that it comprises a numerical string read step.

The optical number reading method according to claim 2, wherein the side presence / absence number reading step according to claim 1 is configured such that each digit of the captured image of the digit string has the substantially 8-character shape. In relation to the position and size of the body, first, for each of the seven side frames of the four vertical side frames and the three horizontal side frames, a predetermined range within the range of the side frame is determined as a side color density measurement location. And secondly, the two colors that are set on the two sides of the long side of the side frame and set in the vicinity in the vicinity of the outer side of the long side as the background color density measurement location and stored. After the density measurement location setting step, the number format storage step for preliminarily storing the numeric forms 0 to 9 and the color density measurement location setting step, the structure of one digit of the image of the digit string imaged For each of the seven side frames of the side color shading measurement location in the side frame. The average value of the color shading level for each pixel measured by the pixel is calculated as the side color shading level, and the average value of the color shading level for each pixel measured at all the pixels in the two background color shading measurement locations is calculated as the background color shading level. A plurality of side frames so that, for each side frame for identifying the presence / absence of a side, a side frame with a side other than the identification target is included after calculating the color density for each side frame and calculating the color density for each side frame. Is selected in advance, the side color shading level of the side frame having the darkest side color shading level among the selected side frames is set as a side colored shading level, and the background color shading level of the side frame to be identified is The side frame of the identification target is defined as a side color density level, and a color density level that is predetermined between the side color density level and the side colorless color level and close to the side color density level as a threshold for determining whether or not there is a side. The side color shading of When the threshold is darker than the threshold value, it is determined that there is a side, and when it is lighter than the threshold value, the side presence / absence determination step for determining that there is no side and the side presence / absence determination step are performed seven times for all the side frames of the construct. And a number reading step of reading a number that matches the number form stored in advance in the number form storing step as a digit number.

According to a third aspect of the present invention, there is provided the optical number reading method according to the second aspect, wherein in the step before the side-frame-based color shading calculation step, each digit of the digit string obtained by imaging displayed on the display screen has an approximately eight-character shape. The display structure is enlarged or reduced so that the image structure of the side frame matches the display structure of the approximately 8-character side frame stored in the color shading measurement location setting step and displayed on the display screen. And a structure matching step that enables movement of the display structure in the vertical and horizontal directions, and allows movement in the vertical and horizontal directions as a single number string composed of the display structures. It is characterized by.

According to a fourth aspect of the present invention, there is provided the optical numeral reading method according to the second or third aspect, wherein in the color shading measurement location setting step, the approximately eight characters of each digit are obtained for each digit of the image of the digit string captured. It is characterized by comprising setting a number frame surrounding each digit number in association with the position and size of the shaped structure.

The optical number reading device according to claim 5 is a digital number capable of displaying any number from 0 to 9 by a substantially 8-character-shaped structure composed of a vertical 4 side frame and a horizontal 3 side frame for each digit. An optical number reading device that reads a number string displayed on a display unit by imaging with a photographing unit, and for each side frame of the component, a color shading level in a target side frame for identifying the presence or absence of a side, State of presence / absence of a side in the side frame of the identification target and the closer one of the color shading level in the side frame of the side frame other than the identification target and the color tone level of the background in the vicinity of the side frame of the identification target Are determined to be the same, the presence / absence of a side is determined, the side presence / absence number reading unit for repeatedly performing the side presence / absence determination for all the side frames of the component and reading the number displayed on the component, and the side presence / absence number A number that reads the number string by repeating the operation of the reading part for all the digits of the number string Characterized in that it comprises a reading unit.

The optical number reading device according to claim 6 is the optical number reading device according to claim 5, wherein the side presence / absence number reading unit is configured to have the substantially 8-character shape of each digit for each digit of the image of the digit string captured. In relation to the position and size of the body, first, for each of the seven side frames of the four vertical side frames and the three horizontal side frames, a predetermined range within the range of the side frame is determined as a side color density measurement location. And secondly, the two colors that are set on the two sides of the long side of the side frame and set in the vicinity in the vicinity of the outer side of the long side as the background color density measurement location and stored. For each of the seven side frames of the density measurement location setting unit, the number form storage unit that stores the number forms of 0 to 9 in advance, and the structure of one digit of the image of the photographed number sequence, The average value of the color shading level for each pixel measured at all the pixels in the side color shading measurement location in the side frame is Color density calculation unit for each side frame, which calculates the average value of color density levels for each pixel measured at all pixels of the two background color density measurement locations, and identifies the presence or absence of the edge For each side frame to be selected, a plurality of side frames are selected in advance so that a side frame with a side other than the identification target is included, and the side frame having the darkest color tone level among the plurality of selected side frames is selected. The side color density level is a side color density level, the background color density level of the side frame to be identified is a side colorless density level, and the side color is between the side color density level and the side colorless density level. As a threshold value for determining the presence / absence of a side, the color tone level determined in advance near the shade level is determined to be edged if the side color shade level of the side frame to be identified is darker than the threshold value, and is lighter than the threshold value Judgment of presence / absence of edge And a number reading unit that performs the edge presence / absence determination unit seven times for the entire side frame of the component and reads a number that matches a number form stored in advance in the number form storage unit as a digit number And.

The optical number reading device according to claim 7 is the optical number reading device according to claim 6, wherein, before the side-frame color tone calculation unit is activated, each digit of the digit string obtained by imaging displayed on the display screen has an approximately 8-character shape. The display structure is enlarged or reduced so that the image structure of the side frame matches the display structure of the approximately 8-character side frame stored in the color shading measurement location setting unit and displayed on the display screen. Operation of the component matching unit that enables movement of the display component in the vertical and horizontal directions, and allows movement in the vertical and horizontal directions by integrating the numeric string of the display components. It is characterized by.

The optical number reading device according to claim 8 is the optical number reading device according to claim 6 or 7, wherein in the color density measurement location setting unit, for each digit of the image of the digit string imaged, the approximately eight characters of each digit. It is characterized by comprising setting a number frame surrounding each digit number in association with the position and size of the shaped structure.

  The invention according to claim 1, 2, 5, or 6 is a watt-hour meter even when a gradation is formed in the background area of the digital numeral display portion imaged by the photographing means due to the influence of light reflection or shadow. There is an effect that it is possible to accurately and accurately read the number on the digital number display portion for displaying the integrated amount of the number.

  The invention according to claim 3 or 7 is displayed on the screen in a state where the image constituting body 48 constituting each number of each digit of the digital number display part of the watt hour meter photographed with the fisheye lens is small or displaced. The position and size of the display structure 49 constituting the number for each digit of the stored digital number display portion can be adjusted to match the position and size of the image structure 48, The measurement of the color shading level can be made accurate without shifting the measurement position, and the number can be read accurately.

  The invention according to claim 4 or 8 is the position and size of the stored structure for each digit of the digital number display unit and the position of the structure for each digit of the digital number display unit of the watt-hour meter to be photographed. In addition, an effect of facilitating matching with the size is achieved.

It is a schematic explanatory drawing which shows the example of arrangement | positioning of the various apparatuses which comprise this invention. It is a flowchart which shows the step of the optical number reading method of this invention. It is a flowchart which shows the step of the optical number reading method of this invention. It is a figure which shows the system configuration | structure of the optical number reader of this invention. It is explanatory drawing of the substantially 8-character-shaped structure which consists of a vertical 4 side frame and a horizontal 3 side frame, (a) is the figure which displayed only the side frame, (b) displayed the digital numbers 0-9. In the figure, (c) is a diagram showing an example of digital numbers displayed on a watt hour meter or the like. It is a figure which shows one example of the state in which the gradation was formed in the background of a digital number. It is a figure explaining that even if the color shading level is the same, the color shading level looks different due to the difference in the color shading level of the background. It is a figure explaining the example of the form of the digital number display part of the watt-hour meter imaged and displayed on the screen by imaging | photography means, such as a camera, (a) is a figure which shows the state of the digital number display part of the watt-hour meter of imaging | photography object (B) is a diagram showing the state of the digital number display part of the watt-hour meter of an image taken with a fisheye lens camera. It is explanatory drawing of the structure row | line | column memorize | stored in the color shading measurement location setting step. This is an explanatory diagram when the position and size of the digital number sequence stored in the device is matched with the position and size of the image on the digital number display section of the watt-hour meter. (A) is taken with the camera It is a figure which shows the case where all the positions and the magnitude | sizes of the image of the digital number display part of the watt-hour meter are the same, (b) shows the position and magnitude | size of the image of the digital number display part of the watt-hour meter image | photographed with the fisheye lens. In the figure, (c) is a diagram showing the matching of the position and size of the digital number sequence stored in the apparatus to the position and size of the image of the digital number display section of the watt-hour meter photographed. It is explanatory drawing of the substantially 8-character-shaped structure which consists of a vertical 4 side frame and a horizontal 3 side frame, (a) is a figure explaining a color shade measurement part, (b) is description of a side frame and a number frame. FIG. It is explanatory drawing when calculating the color shading of the side color shading measurement location and two background color shading measurement locations with respect to one side frame. It is explanatory drawing of a side presence determination step. It is a figure which shows the example of arrangement | positioning of the apparatus which comprises this invention at the time of installing many watt-hour meters.

  When the digital number display unit 26 that displays the accumulated amount of the watt hour meter is imaged, as shown in FIG. 6, the background 45 other than the number of the meter is the same color, but gradation is generated by irradiation of light such as illumination or sunlight. May be formed. When the gradation is formed on the background 45, for example, as shown in FIG. 7, if the gradation is formed on the background g so that the color density is dark on the right side and light on the left side, the color shades of the range m1 and the range m2 Even if the level is the same, the range m2 where the color shading level of the background g is placed on the darker side looks light, and the range m1 where the color shading level of the background g is placed on the lighter side looks dark. As described above, in FIG. 6, if there is an edge forming a number in the dark portion of the background 45 where the gradation is formed, the difference in color shade between the side forming the number and the background 45 is reduced and the digital number is reduced. In the case of FIG. 6, for example, there is a problem that “8” is erroneously read as “6”.

  As shown in FIG. 1, the optical number reading methods 1, 10 and the apparatus 30 of the present invention include a digital number display unit 26 that displays the integrated amount of the watt hour meter 21, a photographing unit 22 such as a camera, and a photographed image. An image recording device 23 for storing, an image display unit 25 for displaying the captured image of the digital display unit 26, and a control unit 24 are provided. When a plurality of watt-hour meters 21 are installed, as shown in FIG. 14, photographing means 22 such as a camera is installed facing each watt-hour meter 21 and stored in one image recording device 23. An image is displayed on one image display unit 25.

As shown in FIG. 2, the optical number reading method 1 according to the present invention is any one of 0 to 9 by an approximately 8-shaped structure 40 including a vertical four-side frame 41 and a horizontal three-side frame 41 for each digit. 1 is an optical number reading method 1 for reading a number string displayed on the digital number display unit 26 capable of displaying the number by imaging by a photographing means, and for each side frame 41 of the structure 40, the presence or absence of a side is identified. The color shading level in the target side frame 41 is the color shading level in the side frame having a side in the side frame 41 other than the identification target, and the color shading level of the background 45 in the vicinity of the identification target side frame 41. The side presence / absence state in the side frame 41 to be identified is the same as the nearer one of the two, and the presence / absence of the side is determined, and the side presence / absence determination is repeatedly performed for all the side frames of the component 40. Side number reading step 2 for reading the number displayed in 40, and the side Free numbers reading step 2 is repeated all digits fraction of the digit sequence comprises a numerical string reading step 8 for reading the numerical string.

As shown in FIG. 3 showing the optical number reading method 10, the image captured by the image capturing unit 22 is captured by the image capturing unit 22 such as a camera. The digital number display unit 26 displays the integrated amount of the watt hour meter 21. The image is displayed on the screen of the image display unit 25 by the photographing step 12, the image storing step 13 for storing the image photographed in the photographing step 12, and the image displaying step 14 for displaying the stored image on an image display means such as a screen. The

As shown in FIG. 5 (a), the optical number reading methods 1 and 10 of the present invention are configured by a substantially eight-shaped structure 40 composed of a vertical four-side frame 41 and a horizontal three-side frame 41 for each digit. The digit string displayed as shown in FIG. 5C is read by imaging by the photographing means on the digital numeral display unit 26 capable of displaying any one of digital numerals 43 as shown in FIG. 5B. Is the method. As shown in FIG. 5C, the presence / absence of the decimal point 42 can be determined by the same method as the determination of the presence / absence of a side.

Then, the side presence / absence number reading step 2 is associated with the position and size of the approximately eight-shaped structure 40 of each digit for each digit of the captured image of the digit string. For each of the seven side frames 41 of the four vertical side frames 41 and the three horizontal side frames 41, a predetermined range (for example, range A in FIG. 12) within the range of the side frame 41 is set as the side color density measurement location. And secondly, two ranges (for example, a range B and a range C in FIG. 12) which are predetermined on both sides of the long side of the side frame 41 and in the vicinity of the outer side from the periphery of the long side. After the color density measurement location setting step 4 for setting and storing the color density measurement location, the number form storage step 3 for preliminarily storing the number forms of 0 to 9, and the color density measurement location setting step 4, the image was taken. The structure 4 of one digit of the image of the number sequence For each of the seven side frames 41, the average value of the color density levels for each pixel measured at all the pixels in the side color density measurement portion in the side frame 41 is calculated as the side color density level, and the two background colors are calculated. After the color density calculation step 5 for each side frame for calculating the average value of the color density levels for each pixel measured at all the pixels at the density measurement location as the background color density level, the presence / absence of the side is determined after the color density calculation step 5 for each side frame. For each side frame 41 to be identified, a plurality of side frames 41 are selected in advance so that a side frame 41 with a side other than the identification target is included, and the side color shading level is the highest among the plurality of selected side frames 41. The side color shading level of the dark side frame 41 is a side colored shading level, the background color shading level of the side frame 41 to be identified is a side colorless shading level, and the side colored shading level and the side colorless shading level are Between and the marginal color shading If the side color density level of the side frame 41 to be identified is darker than the threshold value, it is determined that there is a side. The side presence / absence determination step 6 for determining that there is no side and the side presence / absence determination step 6 are performed seven times 41/41 of the whole side frame of the structure 40, and the numbers stored in advance in the number form storage step 3 A number reading step 7 for reading a number matching the form as a digit number.

The color shading measurement location setting step 4 is first illustrated in association with the position and size of the approximately 8-shaped structure 40 of each digit for each digit of the captured image of the digit string 44. One side frame for each of the seven side frames 41 of the vertical four side frame 41 and the horizontal three side frame 41 as shown in any of the side frame items 11 to 11a of FIG. A predetermined range within the range of 41 is set as a side color shading measurement location, and secondly, the one side frame as shown in ranges a and b in FIG. 11A and ranges B and C in FIG. Two predetermined ranges on both sides of the long side and in the vicinity of the outer side from the periphery of the long side are set and stored as the background color density measurement locations. For example, an RBG value is used as a measurement value of color shading.

Here, in the color shading measurement location setting step 4, for each digit of the captured image of the digit string, in association with the position and size of the approximately eight-shaped structure 40 of each digit, FIG. As shown in FIG. 11 (b), thirdly, a number frame 46 for enclosing each digit number is set.

Next, the number form storage step 3 stores in advance the form of digital numbers 43 of 0 to 9 as shown in FIG. 5B, for example, which are displayed in the captured image of the number string 44.

Next, the color tone calculation step 5 for each side frame is performed for each of the seven side frames 41 of the four vertical side frames 41 and the three horizontal side frames 41 of one digit of the captured image of the number string 44. 12, the average value of the color shading levels for each pixel measured at all the pixels in the range A of the side color shading measurement portion of one side frame 41 is calculated as the side area color shading level, and the two backgrounds are calculated. The average value of the color shading levels for each pixel measured at all the pixels in the range B and range C of the color shading measurement location is calculated as the background color shading level. For example, when the first square in FIG. 12 is one pixel, the range of all pixels in the side color density measurement portion of one side frame 41 corresponds to the range A surrounded by a black line, and the two background colors The range of all pixels in the light and shade measurement area corresponds to the range B and the range C surrounded by black lines.

Next, the side presence / absence determination step 6 selects a plurality of other side frames 41 in advance so that the side frames 41 constituting the numbers displayed in the image are included for each side frame 41 for identifying the presence / absence of a side. The background color shading level of the side frame 41 for identifying the presence / absence of the side is determined by setting the side color shading level of the side frame 41 having the darkest side color shading level among the plurality of selected side frames 41 to be the side colored shading level. The side presence / absence density level is identified, and the presence / absence of the side is identified by using a predetermined color density level between the side color density level and the side colorless level as the threshold value of the side presence / absence determination. When the side area color shading level of the side to be selected is darker than the threshold value, it is determined that the side is present, and when it is lighter than the threshold value, it is determined that the side is absent. As shown in FIG. 3, the side presence / absence determination step 6 is performed when the size of the image is not uniform as shown in FIG. 8B. To be implemented after

As an example of selecting the plurality of other side frames 41 in advance, when the range of the side frame 41 for identifying the presence / absence of the side is set as a range a, when the side frame A is set as a side, the adjacent side frame B or side frame is selected. Since at least one of the side frames 41 has a side, the side frame B and the side frame are selected, and when the side frame 41 for identifying the presence or absence of the side is set as the side frame B, the side frame B is set as a side In this case, since at least one side frame 41 of the adjacent side frames a or side frame c has a side, the side frame a and the side frame c are selected, and the side frame 41 for identifying the presence or absence of the side is selected. In the case where the side frame C is set as a side, since at least one side frame 41 of the adjacent side frames B or side frames D is a side, select the side frame B and the side frame D, When the side frame 41 for identifying the presence / absence of a side is set as the side frame D, when the side frame D is set as a side, at least one of the adjacent side frame c or side frame e Since the side frame 41 has a side, the side frame C and the side frame ho are selected. Since at least one side frame 41 of the frame D or the side frame and the opposite side frame C has a side, the side frame 41 is selected by selecting the side frame D, the side frame, and the side frame C, and identifying the presence or absence of the side. When the side frame is a side frame, when the side frame is a side frame, since at least one side frame 41 of the adjacent side frame a or side frame is a side frame, the side frame a and the side frame frame When the side frame 41 for identifying the presence / absence of the side is a side frame, if the side frame is a side frame, at least one side frame 41 of adjacent side frames B or side frames is Since there is a border, the border frame B and the border frame are selected.

As shown in FIG. 11A and FIG. 13, the presence / absence of a side is identified by setting the side color shading level of the side frame having the darkest side color shading level among the selected side frames 41 to the side colored shading. For example, in the case where it is assumed that the side presence / absence identification for the side frame A in FIG. 11A is performed, the side color density level of the side frame B is compared with the side color density level of the side frame. The side color density level of the side frame 41 is defined as a side color density level U. Here, when the side frame a has a side, the numbers 0, 2, 3, 5, 6, 7, 8, and 9 always have at least one side of the side frame B and the side frame. In the case where the presence is displayed in black, the black RBG value becomes the edged color shading level. On the other hand, when the side frame i is sideless, the number 4 of 1 always has at least one side of the side frame B and the side frame, so for example, when the side color is displayed in black, the black RBG value is displayed. Is the marginal color shading level.

Further, since the background color shading level of the side frame a is the range a and the range b shown in FIG. 11A, the background color shading level of the range a and the range b is set to the side colorless shading level W. Here, if the background color is white, the background color shading level becomes a white RBG value.

Then, a predetermined color shading level between the black RBG value of the side colored shading level U and the white RBG value of the side colorless shading level W and close to the sided shading shading level U is determined as a side presence / absence determination. As the threshold S, if the side color density level of the side for identifying the presence / absence of the side is darker than the threshold S, it is determined that there is a side, and if it is lighter than the threshold S, it is determined that there is no side. This threshold value S is determined by setting the color shading level in advance so as not to erroneously determine that there is no edge because it is determined that the edge is background, and not to be erroneously determined as edge.

Next, when the threshold value S is set to, for example, an RBG value closer to the edge color density level U than an intermediate T between white and black, the side color intensity level of the side frame A is indicated by an arrow F as shown in FIG. In this case, it is determined that there is a side because it is darker than the threshold value S, and in the case of the arrow G, it is determined that there is no side because it is lighter than the threshold value S and is closer to the side colorless gray level. In this way, the side presence / absence determination is performed in units of the side frame 41.

Next, in the number reading step 7, the side presence / absence determination step 6 is performed seven times for all the side frames of the vertical four side frame 41 and the horizontal three side frame 41, and stored in advance in the number form storage step 3. The number that matches the number form is confirmed as the number of the digit that has been executed seven times. In this way, a single digit is read.

Next, the number string reading step 8 repeats the side presence / absence determination step 6 to the number reading step 7 by the number of digits of the number string to read all digits of the number string. In this way, the numeric string displayed on the digital numeral display unit 26 can be read accurately.

The structure matching step 11 will be described. First, a digital number display section 26 that displays the integrated amount of the watt-hour meter is displayed in black as an image structure 48 as shown in FIG. The image component 48 is a component when the size of the image component 48 in the component row 47 is the same as shown in FIG. 8A or when the image component 48 is photographed with a fisheye lens as shown in FIG. 8B. In some cases, the size of the image construct 48 in the column 47 becomes smaller toward the left and right ends than in the central portion. Next, the structure 40 of the structure row 47 stored in the color shading measurement location setting step 4 and displayed on the screen is displayed in black as a display structure 49 as shown in FIG. As shown in FIG. 9, the size of the display structure 49 in the structure row 47 is the same.

In the structure matching step 11, first, the stored structure row 47 as shown in FIG. 9 is superimposed on the taken image structure row 47 as shown in FIG. Then, in the case where the image structures 48 in the structure row 47 as shown in FIG. 8A have the same size, the image is stored as the structure row 47 of the captured image as shown in FIG. 10A. The size / position of the component row 47 matches, and the size / position of the image component 48 and the display component 49 of each digit match. However, as shown in FIG. 8B, in the case of the structure row 47 in which the size and position of the image structure 48 of the image taken by the photographing means 22 such as a fisheye lens is different as shown in FIG. Therefore, the size and position of the component row 47 are not matched, and the digit and the size and position of the image construct 48 and the display component 49 are not matched. In this case, the size and position of the display structure 49 of the structure row 47 stored in the image structure 48 of the structure row 47 of the image captured in the structure matching step 11 and displayed on the screen are adjusted. As shown in FIG. When matching, the number frame 46 of each digit of the display structure 49 can be easily matched by adjusting so as to surround the number of each digit of the image structure 48.

That is, in the step prior to the color shading calculation step 5 for each side frame, the color shading measurement location is added to the image construct 48 of the approximately 8-character side frame 41 of each digit of the digit string obtained by imaging displayed on the display screen. Each display component 49 can be enlarged or reduced so that each of the display components 49 of the substantially eight-shaped side frame 41 stored in the setting step 4 and displayed on the display screen matches. The individual display components 49 can be moved in the vertical and horizontal directions, and the component row 47 composed of the plurality of display components 49 can be integrally moved in the vertical and horizontal directions. A structure matching step 11 is provided. As a result, the size and position of the component row 47 including the image component 48 of the captured image and the component row 47 including the stored display component 49 are matched.

Next, the optical number reading device 30 is a digital number display unit capable of displaying any number from 0 to 9 with a substantially 8-character-shaped structure composed of four vertical side frames and three horizontal side frames for each digit. An optical number reading device for reading a number string displayed on the image by means of imaging means, and for each side frame of the structure, the color shading level in the side frame for identifying the presence or absence of a side is an identification target The side presence / absence state in the side frame of the identification target is the same between the color gray level in the side frame other than the side frame and the color tone level of the background in the vicinity of the side frame of the identification target. The side presence / absence number reading unit that repeats the side presence / absence determination for all side frames of the component and reads the number displayed on the component, and the side presence / absence number reading unit Reading the number string by repeating the operation of all the digits of the number string It comprises a part, a.

Then, the side presence / absence number reading unit is associated with the position and size of the approximately 8-character-shaped structure of each digit for each digit of the image of the digit string that has been imaged. For each of the seven side frames of the side frame and the three horizontal side frames, a predetermined range within the range of the side frame is set as a side color shading measurement point, and secondly, the long side of the side frame A color shade measurement location setting unit that sets and stores two predetermined ranges on both sides and in the vicinity of the outer side from the periphery of the long side as a background color shade measurement location, and forms of the numbers 0 to 9 Measured at all pixels in the side color density measurement portion in the side frame for every seven side frames of the number form storage unit stored in advance and the structure of one digit of the captured image of the number sequence The average value of color shading levels for each pixel is calculated as the side color shading level, and the two background color shading measurements are performed. A color tone calculation unit for each side frame that calculates an average value of color tone levels for each pixel measured at all pixels as a background color tone level, and for each side frame that identifies the presence or absence of a side, A plurality of side frames are selected in advance so as to include a side frame, the side color shading level of the side frame having the darkest side color shading level among the plurality of selected side frames is set as a side colored shading level, and the identification is performed. The background color shading level of the target side frame is set to a side colorless shading level, and a predetermined color shading level between the side colored shading level and the side colorless shading level and close to the side coloring shading level is determined to be a side presence / absence A side presence / absence determination unit that determines that a side is present when the side color shading level of the side frame to be identified is darker than the threshold, and determines that there is no side when the threshold is lighter than the threshold, and the side Presence / absence determination unit 7 times for all sides of the structure Subjected to, and a number reading unit for reading a number that matches the form of the number that was previously stored in the numerical form storage unit as a number of digits.

Before operating the color tone calculation unit for each side frame, the color tone measurement location setting unit stores the image structure of the approximately 8-character side frame of each digit of the digit string obtained by imaging displayed on the display screen. The display structure can be enlarged or reduced so that the display structure of the substantially 8-character side frame displayed on the display screen can be matched, and the display structure can be moved in the vertical and horizontal directions. And the operation | movement completion of the structure matching part which enables the movement to the up-down and left-right direction as a number string which consists of the said display structure is integrated.

Then, in the color shading measurement location setting unit 33, for each digit of the captured image of the number string 44, each digit is associated with the position and size of the approximately 8-character structure of each digit. Setting number frames 46 each enclosing a number.

DESCRIPTION OF SYMBOLS 1 Optical number reading method 2 Side presence / absence number reading step 3 Number form memory step 4 Color shade measurement location setting step 5 Color density calculation step by side frame 6 Edge presence / absence judgment step 7 Number reading step 8 Numeric string reading step 10 Optical number Reading method 11 Constituent matching step 21 Watt meter 22 Imaging unit 23 Image storage device 24 Control unit 25 Image display unit 26 Digital number display unit 30 Optical number reading unit 31 Edge presence / absence number reading unit 32 Number string reading unit 33 Color Color measurement location setting section 34 Number form storage section 35 Color density calculation section by edge frame 36 Edge presence / absence determination section 37 Number reading section 38 Structure matching section 40 Structure 41 Edge frame 42 Decimal point 43 Digital number 44 Number string 45 Background 46 Number frame 47 Constituent row 48 Image constituent 49 Display constituent A Range B Range C Range S Threshold T Intermediate U Side colored shade level W Side colorless shade level g Background m1 Range m2 Range

Claims (8)

Imaging by a photographing means a digit string displayed on a digital numeral display unit capable of displaying any number from 0 to 9 by a substantially 8-character-shaped structure consisting of a vertical 4 side frame and a horizontal 3 side frame for each digit. An optical number reading method for reading by:
For each side frame of the construct, the color shading level in the target side frame for identifying the presence / absence of a side is the color shading level in the side frame with side in the side frame other than the identification target and the side frame for the identification target. The presence / absence of a side is determined by determining that the nearer one of the background color shade levels in the vicinity of and the side presence / absence state in the side frame to be identified are the same, and the side presence / absence determination is performed on all the side frames of the construct A number reading step that reads the number displayed on the component by repeating the number of times, and a number string reading step that reads the number string by repeating the number reading step for all the digits of the number string. An optical number reading method comprising: The side presence / absence number reading step comprises:
For each digit of the captured image of the digit string, first, the seven vertical four-side frames and three horizontal side frames are associated with the position and size of the approximately eight-shaped structure of each digit. For each side frame, a predetermined range within the range of the side frame is set as a side color density measurement point, and secondly, both sides of the long side of the side frame and the periphery of the long side A color shading measurement location setting step for setting and storing two predetermined ranges in the vicinity of the outer direction as background color shading measurement locations;
A number form storing step for storing in advance the number forms of 0 to 9;
After the color density measurement location setting step, measurement was performed on all the pixels of the side color density measurement location in the side frame for every 7 side frames of the structure of one digit of the captured image of the number sequence. A side for calculating an average value of color shading levels for each pixel as a side color shading level, and calculating an average value of color shading levels for each pixel measured at all pixels of the two background color shading measurement points as a background color shading level A color tone calculation step for each frame;
After each side frame color shading calculation step, for each side frame for identifying the presence or absence of a side, a plurality of side frames are selected in advance so that a side frame with a side other than the identification target is included, and the selected plurality of side frames The side color shading level of the side frame having the darkest side color shading level is set as a side colored shading level, the background color shading level of the side frame to be identified is set as a side colorless shading level, and the side colored shading level When the side color shading level of the side frame to be identified is darker than the threshold, with the color shading level set in advance between the side colorless shading level and close to the side colored shading level as a threshold for judging whether or not there is a side Is determined to have a side, and if it is less than the threshold and is light, a side presence / absence determination step that determines that there is no side;
A number reading step of performing the edge presence / absence determination step seven times for all side frames of the structure, and reading a number that matches the number form stored in advance in the number form storage step as a digit number; The optical number reading method according to claim 1, further comprising: In the step before the side frame color shading calculation step,
The image structure of the approximately 8-character-shaped side frame of each digit of the digit string displayed on the display screen is stored in the color shading measurement location setting step and displayed on the display screen. The display structure can be enlarged or reduced so that the display structures can be matched, the display structure can be moved in the vertical and horizontal directions, and the numeric string composed of the display structures can be integrated vertically. The optical number reading method according to claim 2, further comprising a structure matching step that enables movement in the left-right direction. In the color shading measurement location setting step, for each digit of the captured image of the digit string, the digit of each digit is associated with the position and size of the approximately eight-shaped structure of each digit. 4. The optical number reading method according to claim 2, further comprising setting a number frame. Imaging by a photographing means a digit string displayed on a digital numeral display unit capable of displaying any number from 0 to 9 by a substantially 8-character-shaped structure consisting of a vertical 4 side frame and a horizontal 3 side frame for each digit. An optical number reader for reading by
For each side frame of the construct, the color shading level in the target side frame for identifying the presence / absence of a side is the color shading level in the side frame with side in the side frame other than the identification target and the side frame for the identification target. The presence / absence of a side is determined by determining that the nearer one of the background color shade levels in the vicinity of and the side presence / absence state in the side frame to be identified are the same, and the side presence / absence determination is performed on all the side frames of the construct A side presence / absence number reading unit that repeats the number of times and reads the number displayed on the structure, and a number string reading unit that reads the number string by repeating the operation of the side presence / absence number reading unit for all the digits of the number string. An optical number reading device comprising: The side presence / absence number reading unit,
For each digit of the captured image of the digit string, first, the seven vertical four-side frames and three horizontal side frames are associated with the position and size of the approximately eight-shaped structure of each digit. For each side frame, a predetermined range within the range of the side frame is set as a side color density measurement point, and secondly, both sides of the long side of the side frame and the periphery of the long side A color density measurement location setting unit for setting and storing two predetermined ranges in the vicinity of the outer direction as the background color density measurement location;
A number form storage unit for previously storing the number forms of 0 to 9,
For each of the seven side frames of the structure of one digit of the captured image of the digit string, the average of the color shading levels for each pixel measured at all the pixels of the side color shading measurement location in the side frame A value as a side color shading level, and a color shading calculation unit for each side frame that calculates an average value of color shading levels for each pixel measured at all pixels of the two background color shading measurement locations as a background color shading level;
For each side frame for identifying the presence or absence of a side, a plurality of side frames are selected in advance so as to include a side frame with a side other than the identification target, and the side color shading level is the darkest among the plurality of selected side frames. The side color shading level of the side frame is set as a side colored shading level, the background color shading level of the side frame to be identified is set as a side colorless shading level, and is between the side colored shading level and the side colorless shading level. As a threshold value for determining the presence / absence of a side, the color tone level determined in advance near the side color tone level is determined to be side if the side color tone level of the side frame to be identified is higher than the threshold value, and less than the threshold value If it is light, the side presence / absence determination unit that determines that there is no side,
A number reading unit that performs the edge presence / absence determination unit seven times for the entire side frame of the component, and reads a number that matches a number form stored in advance in the number form storage unit as a digit number; The optical number reader according to claim 5, comprising: Before operating the side frame color shading calculation unit,
The image structure of the approximately 8-character side frame of each digit of the digit string obtained by imaging displayed on the display screen is stored in the color shading measurement location setting unit and is displayed on the display screen of the approximately 8-character side frame. The display structure can be enlarged or reduced so that the display structures can be matched, the display structure can be moved in the vertical and horizontal directions, and the numeric string composed of the display structures can be integrated vertically. 7. The optical number reading device according to claim 6, wherein the operation of the component matching unit that enables movement in the left-right direction is completed. In the color density measurement location setting unit, each digit of the digit string is associated with the position and size of the approximately 8-character-shaped structure of each digit for each digit of the captured image of the digit string. The optical number reader according to claim 6, further comprising setting a number frame to be set.