JP2019096304A - Image processing device, control method thereof, and program - Google Patents

Abstract

To obtain a correct value to be indicated by a pointer of an analog meter regardless of the shape of the pointer.SOLUTION: An image processing device acquires an image of a meter captured by an imaging device, sets an area to be an object of edge detection processing in the image in accordance with an operation of a user, and performs edge detection processing with respect to the area set in the image. The image processing device sets a value to correct a position of an edge location to be detected, corrects a position of the detected edge location on the basis of the set value, and calculates a value to be indicated by a pointer of a meter in accordance with the position of the corrected edge location.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an image processing apparatus for processing an image captured by a meter and reading a value indicated by a pointer of the meter, and a control method and program thereof.

  Conventionally, an analog meter that measures physical quantities such as temperature, pressure, rotation speed, current, and voltage is photographed by an imaging device, a photographed image is analyzed, and a value indicated by a pointer of the analog meter is output. (See Patent Document 1).

JP 2004-133560 A

  However, in Patent Document 1, since the shape of the pointer is not considered, an incorrect edge may be detected depending on the thickness of the pointer or the design of the pointer, and an accurate measurement value may not be obtained. there were.

  One of the inventions according to the present application is an image processing apparatus, which is an acquisition unit for acquiring an image of a meter captured by an imaging apparatus, and responding to a user operation of a region to be subjected to edge detection processing in the image. A first setting unit configured to perform the setting, a detection unit configured to execute edge detection processing on the set region of the image, and a second configured to set a value for correcting the position of the detected edge portion. Setting means for correcting the position of the detected edge portion based on the value, and calculating means for calculating the value indicated by the pointer of the instrument according to the position of the corrected edge portion. It is characterized by

  According to the present invention, the correct value indicated by the pointer can be obtained regardless of the shape of the pointer of the analog meter.

It is a figure showing an example of the composition of the whole system concerning one embodiment of the present invention. FIG. 7 is a flowchart showing an example of the operation in the setting mode of the image processing apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart showing an example of the operation in the setting mode of the image processing apparatus according to the embodiment of the present invention. It is a figure which shows an example of the analog meter setting screen which concerns on one Embodiment of this invention. It is a figure which shows an example of the analog meter setting screen which concerns on one Embodiment of this invention. It is a figure which shows an example of the analog meter setting screen which concerns on one Embodiment of this invention. It is a figure which shows an example of the analog meter setting screen which concerns on one Embodiment of this invention. It is a flowchart figure which shows an example of operation | movement in the driving mode of the image processing apparatus which concerns on one Embodiment of this invention. It is a conceptual diagram of the analog meter concerning one embodiment of the present invention. It is a figure which shows an example of the analog meter setting screen which concerns on one Embodiment of this invention. FIG. 7 is a flowchart showing an example of the operation in the setting mode of the image processing apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart showing an example of the operation in the setting mode of the image processing apparatus according to the embodiment of the present invention. It is a figure which shows an example of the analog meter setting screen which concerns on one Embodiment of this invention. It is a flowchart figure which shows an example of operation | movement in the driving mode of the image processing apparatus which concerns on one Embodiment of this invention. It is a conceptual diagram of the analog meter concerning one embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, the components described in this embodiment are merely examples, and the scope of the present invention is not limited to them.

(First embodiment)
In this embodiment, an image processing apparatus will be described which reads a measured value in accordance with a pointer indicating physical quantities such as temperature, pressure, rotation number, current, voltage and the like in a circular analog meter (round meter).

<System configuration>
FIG. 1 is a diagram showing the overall configuration of a system including an image processing apparatus 100 according to the present embodiment. In FIG. 1, an image processing apparatus 100 is realized by a computer apparatus, and executes image processing described below by executing a predetermined control program. The control unit 101 controls the entire image processing apparatus 100 and is realized by, for example, a CPU (Central Processing Unit). The ROM 102 stores operation processing procedures of the control unit 101 (for example, programs such as startup processing of a computer and basic input / output processing). The RAM 103 functions as a main memory of the control unit 101. Various programs including a control program for realizing processing to be described later are loaded from the hard disk drive 105 or the like to the RAM 103 and executed by the control unit 101. The RAM 103 also provides a work area when the control unit 101 executes various processing. The display 104 performs various displays under the control of the control unit 101. A hard disk drive (hereinafter, HDD) 105 is used for storing and reading application programs, data, libraries, and the like. The input device 106 is realized by a pointing device, a keyboard, or the like, and inputs data according to the user's operation. A storage medium loading unit (media drive) 107 loads a removable storage medium, and enables reading of data captured by the imaging device 112 and stored in the storage medium. The network interface 108 is connected to the network 111 via the communication line 110. Data is transmitted and received from an external device that can communicate via the network interface 108. In the present embodiment, the image processing apparatus 100 is connected to the imaging apparatus 112 via the network interface 108, and the control unit 101 instructs the imaging apparatus 112 to perform imaging and acquires an image obtained by imaging from the imaging apparatus 112. Record to the HDD 105. A system bus 109 connects between the above-described units, and includes an address bus, a data bus, and a control bus.

  The imaging device 112 acquires image data by imaging a subject, and is realized by an electronic device including an imaging unit, such as a digital still camera, a digital movie camera, or a surveillance camera. The imaging device 112 is connected to the network 111 via the communication circuit 113, and can communicate with the image processing apparatus 100. The analog meter 114 measures physical quantities such as temperature, pressure, rotation speed, current, voltage, etc., and points the measured value by a pointer.

  The image processing apparatus 100 according to the present embodiment operates in two types of modes, a setting mode and an operation mode, in order to realize reading of the measurement value of the analog meter 114. In the setting mode, in accordance with the image of the analog meter 114 taken by the imaging device 112, various information is set in advance to realize reading of the measurement value of the analog meter 114. On the other hand, in the operation mode, based on various information set in the setting mode, the image data of the analog meter 114 photographed by the imaging device 112 is analyzed, and the measurement value of the analog meter 114 is calculated.

  In the present embodiment, it is assumed that an image to be subjected to image processing is a non-compressed or decompressed grayscale 8-bit image. Therefore, the imaging device 112 converts the image data obtained by photographing the analog meter 114 into grayscale image data, and transmits the image data to the image processing device 100 via the network 111. Alternatively, the imaging device 112 may transmit the original image data to the image processing device 100, and the image processing device 100 may convert the image data into grayscale image data. The image processing apparatus 100 stores grayscale image data to be processed in the present embodiment in the HDD 105.

<Processing in setting mode>
First, the processing procedure when the image processing apparatus 100 of this embodiment operates in the setting mode will be described with reference to the drawings.

  The control unit 101 of the image processing apparatus 100 reads an application program for executing the analog meter reading process from the HDD 105 and starts up. The control unit 101 executes the operation described below according to an operating system (OS) and an application program.

  Then, when the application program is activated, the control unit 101 performs display control to display a menu screen on the display 104, and selects either the setting mode or the operation mode according to the operation of the user.

  The operation of the image processing apparatus 100 when the setting mode is selected will be described using the flowcharts of FIGS. 2 and 3.

  First, the control unit 101 determines whether an instruction for acquiring an image captured by the analog meter 114 has been input (S201). When the setting mode is selected on the menu screen described above, the control unit 101 causes the display 104 to display an analog meter setting screen 400 as shown in FIG. 4. A photographing button 402 is an area for instructing the imaging device 112 to perform photographing, storing a photographed image in the HDD 105, and receiving an instruction to read a photographed image from the HDD 105. A read button 403 is an area for receiving an instruction to read an image already stored in the HDD 105. When the control unit 101 detects the user's operation on the photographing button 402 or the reading button 403, the control unit 101 determines that an instruction for acquiring an image is input. When the control unit 101 receives an operation of the user on the shooting button 402 (Yes in S201), the control unit 101 transmits a shooting instruction to the imaging apparatus 112 via the network interface 108. When the imaging device 112 receives an imaging instruction from the image processing device 100, the imaging device 112 performs imaging processing with the analog meter 114 as a subject to generate image data, and transmits the image data to the image processing device 100. The image processing apparatus 100 acquires the image data from the imaging apparatus 112 via the network interface 108, stores the image data in the HDD 105, and reads the image data from the HDD 105 to the RAM 103 (S202). On the other hand, when the control unit 101 receives a user operation on the read button 403 (Yes in S201), the control unit 101 displays a file open dialog. Then, the image data specified by the user in the file open dialog is read from the HDD 105 to the RAM 103 (S202).

  The control unit 101 causes the image display area 401 to display the image data 501 read from the HDD 105 to the RAM 103 as shown in FIG. 5 (S203).

  When the control unit 101 receives a pressing operation on the edge detection area specification button 612, the control section 101 draws and displays a figure for specifying the edge detection area, and receives a user operation to specify the center point of the edge detection area. It determines (S204). For example, when the left click operation of the pointing device (input device 106) is performed on the image data 501 displayed in the image display area 401 (Yes in S204), the control unit 101 sets the coordinates of the position to the edge detection area The coordinates are stored in the RAM 103 as the coordinates of the central point of (S205). A center point 620 is shown in FIG. In the image data 501, the origin of the coordinates is assumed to be at the upper left, the X coordinate increases as it goes to the right, and the Y coordinate increases as it goes downward.

  As shown in FIG. 6, the control unit 101 draws on the image data 501 an arc 621 of an outer circle whose center is the center point 620 and whose radius is the distance to the position where the cursor 629 exists (S206). The radius is changed according to the user moving the cursor 629 on the arc 621 of the outer circle by operating the pointing device and changing the distance from the center point 620, and the control unit 101 changes the arc 621 of the outer circle Redraw. Then, the control unit 101 determines whether the user's operation of specifying the radius of the outer circle has been received (S207). For example, when the left click operation is performed when the cursor 629 is present on the arc 621 of the outer circle (Yes in S207), the control unit 101 determines the distance from the position of the cursor 629 to the central point 620 as the outer circle. The radius is stored in the RAM 103 (S208). Then, based on the center point 620 and the radius of the outer circle, the control unit 101 draws at least a part (partial circle) of the ring on the image data 501 displayed in the image display area 401 (S209). The initial value of the radius of the inner circle of the torus is a value smaller than the radius of the outer circle by a predetermined value (for example, 20 pixels). Further, the start point angle and the end point angle of the partial ring are also drawn using predetermined initial values. In this embodiment, a line passing through a vertical center point 620 of the image display area 401 is taken as a center line 611, and the clockwise direction is a positive angle, and the counterclockwise direction is a negative angle. For example, the partial circle is drawn with the start point angle as an initial value of -140 degrees from the center line 611 and the end point angle as an increase angle of +280 degrees from the start point angle. The radius of the inner circle is changed in response to the user operating the pointing device to move the cursor 629 on the arc 622 of the inner circle (Yes in S210). Accordingly, the control unit 101 stores the distance from the end position of the movement of the cursor 629 to the central point 620 as the radius of the inner circle in the RAM 103 (S211), and draws the inner circle 622 again and displays it (S212) . When the cursor 629 on the arc 621 of the outer circle is moved, the radius of the outer circle is changed, and a value smaller than the radius of the outer circle by a predetermined value (for example, 1 pixel) is stored in the RAM 103 as the radius of the inner circle. (S212).

  When the user operates the pointing device to move the cursor 629 on the start end 623 of the partial ring, the start angle is changed (Yes in S213). Thereby, the control unit 101 stores the angle from the line segment connecting the end position of the movement of the cursor 629 and the center point 620 to the center line 611 as the start angle in the RAM 103 (S214), moves the start end 623 and The ring is redrawn and displayed (S215). If the end position of the movement of the cursor 629 for changing the start angle exceeds the end 624, an angle obtained by adding -220 degrees from the center line 611 is stored in the RAM 103 as the start angle. In addition, the control unit 101 may control the movement of the cursor 629 for changing the start angle to a position not exceeding the end point 624 and to prohibit the movement to an exceeding position.

  The end point angle is changed according to the user operating the pointing device to move the cursor 629 on the end 624 of the partial ring (Yes in S216). Thus, the control unit 101 stores the angle of the line segment connecting the start point 623 of the partial ring, the movement end position of the cursor 629, and the center point 620 in the RAM 103 as an increase angle (end point angle) from the start point angle. (S217). Then, the terminal end 624 is moved to redraw and display the partial ring (S218). If the end position of the movement of the cursor 629 for changing the end point angle exceeds the start end 623, an angle obtained by adding +360 degrees from the start point angle is stored in the RAM 103 as the end point angle. In addition, the control unit 101 may control the movement of the cursor 629 for changing the end point angle to a position not exceeding the start end 623 and to prohibit the movement to an exceeding position.

  The control unit 101 reads the coordinates of the center point 620 of the annular ring, the start point angle, and the end point angle from the RAM 103 as information on the edge detection area 700 in response to the user's operation (S301) Is calculated (S302). The starting point angle of the analog meter is a value obtained by adding a predetermined value (for example, 2 degrees) to the starting point angle of the edge detection area, and the end point angle of the analog meter is a value obtained by subtracting a predetermined value (for example, 4 degrees) from the end point angle of the edge detection area The positions are respectively calculated to be included in the edge detection area. The calculated values are displayed as initial values in the columns of the minimum value angle 701 and the maximum value angle 702 shown in FIG. 7, respectively. Further, a line segment 711 forming an angle 701 of the minimum value from the center line 611 and a line segment 712 forming an angle 702 of the maximum value are displayed on the image data 501. Note that the user operates the input device 106 to input values to the minimum value angle 701 and the maximum value angle 702, or to move the line segment 711 or the line segment 712, thereby starting the analog meter. The angle and the end point angle are changed, and the value of the RAM 103 is updated.

  Then, the control unit 101 performs edge detection processing in the edge detection area 700 according to the values input to the edge direction 703 and the edge strength threshold 704, and stores the coordinates indicating the edge location in the RAM 103 (S303). In this embodiment, Laplacian filter processing is applied to the image data 501 converted to gray scale, and an edge portion is searched from the start end 623 to the end end 624 of the edge detection area 700 of the Laplacian filtered image.

  Here, in the present embodiment, any one of the options “bright to dark”, “dark to light”, and “both light to dark and light from dark” is set as the edge direction 703. Further, the edge strength threshold 704 is a threshold of the difference between adjacent pixel values when detected as an edge location. The greater the difference between adjacent pixel values, the greater the difference between light and shade, and the stronger the edge strength. For example, when “30” is designated as the edge strength threshold 704 by the user operation, the control unit 101 detects a point where the difference between the pixel values of adjacent pixels is 30 or more as a candidate of an edge point. Then, when “bright to dark” is set in the edge direction 703, the control unit 101 compares the values of adjacent pixels with respect to the candidate of the detected edge portion, and changes from a high pixel value to a low pixel value. Determine the location as an edge location. In addition, when “dark to light” is set in the edge direction 703, the control unit 101 compares the values of adjacent pixels with respect to the candidate of the detected edge portion, and the pixel value changes from low to high. The location to be determined is determined as the edge location. When “both light and dark and dark to light” is set in the edge direction, the control unit 101 determines the candidate of the edge portion as the edge portion regardless of the direction of the change of the pixel value.

  The control unit 101 determines whether the determined number of edge locations matches the preset number (S304). In the present embodiment, for example, “2” is set in advance as the number of both ends of the pointer 730. When the pointer 730 has a line of decoration or the like, a number larger than 2 is set in advance. In addition, when pixels at edge locations are adjacent to each other, they are counted as one edge composed of continuous pixels.

  If they do not match (No in S304), a warning dialog is displayed on the assumption that an edge other than the pointer 730 has been detected (S305). For example, it is conceivable that foreign matter such as dust or dirt adheres to the analog meter, and an edge portion of an unnecessary object other than the pointer 730 is erroneously detected.

  On the other hand, if they match (Yes in S304), the control unit 101 draws and displays a first auxiliary line 728 indicating the edge portion closest to the start end 623 on the image data 501. In addition, the control unit 101 sets a needle width correction angle 705 to a line connecting the center point 620 with the first auxiliary line 728 and a point connecting the intersection point 729 of the arc 621 of the outer circle and the second auxiliary line. 725 is drawn and displayed on the image data 501 as a line segment passing through the tip of the pointer 730 (S306).

  The user checks the first auxiliary line 728 and the second auxiliary line 725 drawn on the image data 501, and operates the input device 106 to move the first auxiliary line 728 and the second auxiliary line 725. . This makes it possible to correct the position of the edge or tip of the pointer 730 and change the value of the correction angle 705 of the needle width. Also, the value of the needle angle correction angle 705 can be directly corrected. When the control unit 101 detects that an operation for correcting the needle width correction angle 705 has been performed (Yes in S307), the value of the needle width correction angle is stored in the RAM 103 (S308), and the first auxiliary The line 728 and the second auxiliary line 725 are redrawn and displayed (S309).

  Further, the control unit 101 inputs the minimum value 721 and the maximum value 722 of the analog meter in response to the user's operation (S310). Note that character recognition processing may be performed on the image data 501, and the minimum value 721 and the maximum value 722 may be automatically acquired and input.

  Then, in response to the user operation, the control unit 101 sets the condition 723 of the measurement value for performing notification (S311). When operating in the operation mode, the control unit 101 performs notification when the pointer 730 of the analog meter points out of the range of the predetermined value or in the range of the predetermined value.

  When the control unit 101 receives the user's operation on the end button 731 (Yes in S312), the control unit 101 ends the operation in the setting mode. When the operation in the setting mode is finished, the operation in the operation mode is subsequently started, and the operation mode screen (not shown) is displayed on the display 104 instead of the analog meter setting screen 400. Good.

<Processing in operation mode>
Next, a processing procedure when the image processing apparatus 100 according to the present embodiment operates in the operation mode will be described with reference to the drawings.

  The control unit 101 of the image processing apparatus 100 reads an application program for executing the analog meter reading process from the HDD 105 and starts up. The control unit 101 executes the operation described below according to an operating system (OS) and an application program.

  Then, when the application program is activated, the control unit 101 performs display control to display a menu screen on the display 104, and selects either the setting mode or the operation mode according to the operation of the user.

  The operation of the image processing apparatus 100 of this embodiment when the operation mode is selected will be described using the flowchart of FIG.

  The image processing apparatus 100 is connected to the imaging apparatus 112 via the network interface 108, the control unit 101 instructs the imaging apparatus 112 to perform imaging, acquires an image obtained by imaging from the imaging apparatus 112, and stores it in the HDD 105 ( S801). In the setting mode, the imaging device 112 captures an image of the analog meter 114 at the same position as the image acquired in step S202. The imaging device 112 may perform imaging processing and periodically transmit an image to the image processing apparatus 100, or may continuously deliver streaming. Alternatively, the image processing apparatus 100 may regularly instruct photographing, and in response to that, the imaging apparatus 112 may periodically photograph and transmit an image to the image processing apparatus 100.

  The control unit 101 converts the image acquired from the imaging device 112 into gray scale and displays it on the screen (S802). Alternatively, the imaging device 112 may convert the image into grayscale, and the image processing apparatus 100 may receive the converted image.

  The control unit 101 applies a Laplacian filter to the image data converted to gray scale as in step S303, and performs edge detection processing in the edge detection area of the image subjected to the Laplacian filter (S803). As in step S304, the control unit 101 determines whether the number of detected edge locations matches the number set in advance (S804). If they do not match (No in S804), a warning dialog is displayed on the assumption that an edge other than the pointer 730 has been detected (S805). On the other hand, if they match (Yes in S804), the control unit 101 calculates a line connecting the center point 620 of the analog meter and the intersection point of the edge closest to the beginning of the edge detection area and the arc of the outer circle of the edge detection area. (S806). The control unit 101 specifies that the tip of the pointer 730 exists on a line forming an angle obtained by adding the value set to the needle width correction angle 705 to the line calculated in step S806, and the corrected angle is determined by the RAM 103. (S807).

  Then, the control unit 101 calculates the value indicated by the pointer 730, and stores the calculated value in the HDD 105 (S808). The calculated value is stored in the HDD 105 in association with attribute information such as the measurement date and time.

  The calculation process of step S 808 will be described using the conceptual diagram of the analog meter 114 shown in FIG. The minimum angle (degMin) 901 is an angle set from the center line 611 to the angle 701 of the minimum value. The maximum angle (degInc) 902 is an angle obtained by adding the maximum value angle 702 to the minimum angle. The angle of the pointer (degEdge) 903 is the angle from the minimum angle 901 to the edge of the pointer 730. The needle width correction angle value (deg WN) 904 is an angle set to the needle width correction angle 705.

Then, the value of the minimum value 721 is represented by valMin, and the value of the maximum value 722 is represented by valMax.
valNeedle = (degWN + degEdge) x (valMax-valMin) ÷ degInc + valMin Formula 1

  Assuming that the degEdge 903 is 43 degrees, the needle width correction angle degWN 904 is 2 degrees, the maximum angle degInc is 270 degrees, the minimum value valMin is 0, and the maximum value valMax is 6, the valNeedle is "1".

  Assuming that the degEdge 903 is 205 degrees, the needle width correction angle degWN 904 is 5 degrees, the maximum angle degInc is 270 degrees, the minimum value valMin is 0, and the maximum value valMax is 6, valNeedle is to the second decimal place of the number of significant digits. It will be 44 ".

  Subsequently, the control unit 101 determines whether the value calculated in step S808 satisfies the condition 723 (S809). If determined that the value is satisfied (Yes in S809), notification is given (S810). For example, the control unit 101 displays a warning dialog on the display 104. Further, according to the operation on the warning dialog, an instruction on whether to continue the operation mode may be received. Further, the warning dialog may be displayed on the image data, and an edge detection area, an edge detection position, an auxiliary line passing the tip of the pointer 730, or the like may be displayed on the image data.

  Then, when the control unit 101 receives an end operation (Yes in S811), the operation in the operation mode is ended.

  As described above, in the setting mode, the image processing apparatus 100 according to the present embodiment acquires the image of the analog meter from the imaging device 112 and sets in advance the scale and the pointer. Then, in the operation mode, the image processing apparatus 100 acquires an image of an analog meter from the imaging device 112, detects a pointer 730 according to a preset value, and calculates a value indicated by the pointer 730. Then, the calculated value indicated by the pointer 730 is recorded in the HDD 105 or notified when a predetermined condition is satisfied.

  In this embodiment, in the operation mode, the control unit 101 issues a warning when the number of edges detected in the edge detection area does not match the predetermined value (S805), but the present invention is not limited to this. For example, in order to further improve the reliability, it is detected whether edges are detected from the start point direction and the end point direction, respectively, and the angle formed by the line connecting each edge and the center point 620 is about twice the needle width correction angle May be determined, and a warning may be issued if there is false detection.

  Furthermore, in the present embodiment, the control unit 101 displays a warning and interrupts measurement when the number of edges detected in the edge detection area does not match the predetermined value in the operation mode, but the present invention is limited thereto. Absent. For example, measurement may be continued to notify that the reliability of the calculated value is low.

  Further, in the present embodiment, in the operation mode, the control unit 101 may newly set an area to be subjected to edge detection on the center line from the edge detected in the edge detection area to improve the edge detection accuracy. FIG. 15 is a diagram for explaining the concept of newly setting an area for edge detection on the center line in the analog meter setting screen. The edge detection area in FIG. 15 is the same as that in FIG. Here, when the edge 728 is detected in the edge detection area surrounded by the curves 621 and 622 and the straight lines 623 and 624, the needle width area is newly added to the edge detection area 1501 on the straight line connecting the edge 728 and the center point. The false detection of the edge can be avoided by setting the edge detection area 1501 to the edge detection area 1501 and making the edge detection possible.

  The process of adding an edge detection area and performing edge detection is performed in step S303. Also, by performing in step S 803, it can be performed in combination with a method for avoiding false detection of an edge by a needle width correction angle.

  Further, in the present embodiment, in the setting mode, the radius of the outer circle of the edge detection area may be expanded in a range where the number of values detected in the edge detection area matches the predetermined value. This is because the change in the angle of the pointer 730 can be detected in more detail as the radius of the outer circle of the edge detection area increases.

  Further, in the present embodiment, the Laplacian filter is used in the edge detection processing, but any other filter capable of detecting a high frequency component may be used. When the filter size is large, the positions of the start edge 623 and the end edge 624 of the edge detection area are extended in consideration of the needle width correction angle so that the pointer detection can be performed even if there is a pointer at the start 623 and the end 624 of the edge detection area. It shall be.

  In addition, when the angle 701 of the minimum value and the angle 702 of the maximum value are outside the edge detection area, the start end 623 and the end 624 of the edge detection area are also changed so as to include the angle.

  As described above, since the user can adjust the edge detection area while looking at the image of the analog meter captured by the imaging device, unnecessary edges outside the edge detection area are not detected. It is possible to reduce the possibility of false detection of the value.

  Further, according to the present embodiment, the width from the edge to the tip of the pointer can be adjusted by the value set for the correction angle of the needle width. Thus, even when the shape of the pointer is thick or thin, it becomes possible to accurately calculate the value indicated by the pointer regardless of the shape of the pointer.

  Further, according to the present embodiment, in the setting mode, the user can perform adjustment with a simple operation while looking at the displayed edge detection area. Further, the setting may be changed even while operating in the operation mode.

  Further, according to the present embodiment, the number of edges detected in the edge detection area is compared with a predetermined value, and if different, a warning is issued. Therefore, it is possible to notify the user of the possibility that an erroneous detection is being performed, for example, when a foreign object enters the edge detection area.

  Further, according to the present embodiment, in the operation mode, when the measured value satisfies the predetermined condition or when the reliability of the measured value is low, the edge detection area is superimposed on the image to be measured. An auxiliary line is displayed based on the setting information of and the edge detection position. This allows the user to easily check the situation.

Second Embodiment
In this embodiment, in place of a circular analog meter, an image processing apparatus which reads a measured value in accordance with a pointer indicating physical quantities such as temperature, pressure, rotation number, current, and voltage in a rod-like analog meter (square meter). explain. Description of the same configuration as that of the first embodiment described above will be omitted.

<Processing in setting mode>
First, a processing procedure when the image processing apparatus 100 according to the present embodiment operates in the setting mode will be described with reference to FIGS. 11, 12 and 13.

  The control unit 101 of the image processing apparatus 100 reads an application program for executing the analog meter reading process from the HDD 105 and starts up. The control unit 101 executes the operation described below according to an operating system (OS) and an application program. Then, the control unit 101 executes the same processing as steps S201 to S203 in FIG. 2, and causes the display 104 to display an analog meter setting screen 1000 as shown in FIG.

  When the drag start operation and end operation of the pointing device (input device 106) are performed on the image data 1001 displayed in the image display area 401 (Yes in S1104), the control unit 101 detects the respective positions (1301 and 1302). Is stored in the RAM 103 as opposing vertices of the rectangular area (S1105). Then, a rectangular area is drawn and displayed as an edge detection area 1004 (S1106).

  In response to the user's operation, the control unit 101 reads the coordinates of the vertex from the RAM 103 as information on the edge detection area 1004 (S1201). A value obtained by subtracting a predetermined value from the Y coordinate of the start point 1301 of the edge detection area 1004 and a value obtained by adding the predetermined value to the Y coordinate of the end point 1302 are calculated as the start point coordinate and the end point coordinate of the analog meter (S1202). That is, the edge detection area 1004 is adjusted and set so as to include the start point and the end point of the analog meter. Here, the predetermined value is, for example, 2 pixels. Moreover, each predetermined value may be different. In the present embodiment, the coordinates are represented by values with the upper left of the image data 1001 displayed in the image display area 401 as the origin.

  Then, the control unit 101 performs edge detection processing in the edge detection area 1004 according to the values input to the edge direction 703 and the edge strength threshold 704 as in step S303, and stores the coordinates indicating the edge location in the RAM 103. (S1203). As in step S304, the control unit 101 determines whether the determined number of edge locations matches the preset number (S1204). In this embodiment, the predetermined value is "1". In the present embodiment, the predetermined value is set to “1”, but the user may arbitrarily specify. Even in the case where the pointer is composed of a plurality of lines, measurement is possible.

  If they match (Yes in S1204), the Y coordinate of the position of the horizontal line passing through the determined edge point is set as the initial value of the coordinates of the pointer 1005. Then, the control unit 101 displays each auxiliary line on the image data 1001 (S1206). Specifically, an auxiliary line 1321 is displayed, which indicates a rectangle having the start point 1301 and the end point 1302 as opposing vertices as an edge detection area. In addition, an auxiliary line 1323 indicating the start point of the edge detection area 1004 acquired in S1201, an auxiliary line 1324 indicating the end point, an auxiliary line 1326 indicating the start point of the analog meter calculated in S1202, and an auxiliary line 1327 indicating the end point are displayed. Be done. Further, an auxiliary line 1325 indicating the position of the pointer 1005 calculated in S1205 is drawn. Here, when the correction coordinate 1331 of the needle width is set, the coordinate of the position of the pointer 1005 is corrected reflecting the value, and stored in the RAM 103, and the auxiliary line 1325 is moved and displayed.

  Further, the control unit 101 sets and displays values corresponding to the coordinates of the start point of the analog meter and the values corresponding to the coordinates of the end point on the coordinates 1332 of the minimum value and the coordinates 1333 of the maximum value (S1207).

  Then, in response to the user operation, the control unit 101 sets the condition 723 of the measurement value for performing notification (S1208). When operating in the operation mode, the control unit 101 performs notification when the pointer 1005 of the analog meter points out of the range of the predetermined value or in the range of the predetermined value.

  When the control unit 101 receives the user's operation on the end button 731 (Yes in S312), the control unit 101 ends the operation in the setting mode. When the operation in the setting mode is finished, the operation in the operation mode is subsequently started, and a screen (not shown) of the operation mode is displayed on the display 104 instead of the analog meter setting screen 1000. Good.

<Processing in operation mode>
Next, a processing procedure when the image processing apparatus 100 according to the present embodiment operates in the operation mode will be described with reference to the drawings. The control unit 101 of the image processing apparatus 100 reads an application program for executing the analog meter reading process from the HDD 105 and starts up. The control unit 101 executes the operation described below according to an operating system (OS) and an application program. The description of the same operation and configuration as those of the first embodiment will be omitted.

  The operation of the image processing apparatus 100 of this embodiment when the operation mode is selected will be described using the flowchart of FIG. The control unit 101 executes the same process as steps S801 to S805 in FIG. In the present embodiment, the number of preset edges to be compared in S804 is “1”. Then, the control unit 101 acquires the Y coordinate of the edge portion detected in step S803 as the coordinates of the pointer 1005 (S1406), subtracts the value set in the width correction coordinates 1331 of the needle, and updates the coordinates of the pointer Then, it is stored in the RAM 103 (S1407).

Then, the control unit 101 calculates the value indicated by the pointer 1005, and stores the calculated value in the HDD 105 (S1408). The calculated value is stored in the HDD 105 in association with attribute information such as the measurement date and time. The calculation process of step S1408 will be described. The minimum value coordinate 1332 is yMin, the maximum value coordinate 1333 is yMax, the coordinate of the pointer 1005 is yEdge, the needle width correction coordinate yWN, the minimum value 1334 is valMin, and the maximum value 1335 is valMax, and the formula for calculating the value valNeedle indicated by the needle is Shown in 2.
valNeedle = ((yEdge-yWN)-yMin) x (valMax-valMin) ÷ (yMax-yMin) + valMin Equation 2

  For example, assuming that the coordinate yEdge of the pointer 1005 is 350, the needle width correction coordinate degWN is 0, the minimum value coordinate yMin is 820, the maximum value coordinate yMax is 20, the minimum value valMin is 0, and the maximum value valMax is 8, valNeedle is 4 .7. Also, assuming that the coordinate yEdge of the pointer 1005 is 642, the needle width correction coordinate degWN is 2, the minimum value coordinate yMin is 1240, the maximum value coordinate yMax is 40, the minimum value valMin is 0, and the maximum value valMax is 12, valNeedle is 6 It becomes.

  Then, the control unit 101 executes the same processing as steps S809 to S811.

  As described above, according to the image processing apparatus of the present embodiment, even if the analog meter to be measured is a bar, the user can read the value indicated by the pointer with only simple setting.

(Other embodiments)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

Claims (9)

An image processing apparatus,
Acquisition means for acquiring an image of an instrument taken by the imaging device;
A first setting unit configured to set an area to be subjected to edge detection processing in the image in response to a user operation;
Detection means for performing edge detection processing on the set region of the image;
Second setting means for setting a value for correcting the position of the detected edge point;
A correction unit configured to correct the position of the detected edge based on the value;
An image processing apparatus comprising: calculation means for calculating a value indicated by a pointer of an instrument according to the position of the corrected edge portion.   The area is at least a part of a torus, and the setting means sets at least one of a center, a beginning end, an end, a radius of an outer circle, and a radius of an inner circle of the torus. An image processing apparatus according to Item 1.   The position of the edge point is indicated by an angle, and the calculating means calculates the value indicated by the pointer of the instrument based on the angle between the minimum value and the maximum value of the instrument and the angle of the edge point. The image processing apparatus according to claim 2.   The image processing apparatus according to claim 1, wherein the area is a rectangle, and the setting unit sets opposite vertices of the rectangle.   The position of the edge portion is indicated by the Y coordinate, and the setting means calculates the value indicated by the pointer of the instrument based on the Y coordinate of the minimum value and the maximum value of the instrument and the Y coordinate of the edge portion. The image processing apparatus according to claim 4, characterized in that A third setting unit configured to set in advance the number of edge locations to be detected;
The image processing according to any one of claims 1 to 5, further comprising notification means for giving a notification if the number of detected edge locations does not match the preset number. apparatus.   7. The image processing apparatus according to claim 6, further comprising changing means for changing the area in a range in which the number of the detected points coincides with the preset number. A control method of the image processing apparatus,
Acquiring an image of the instrument taken by the imaging device;
Setting an area to be subjected to edge detection processing in the image in response to a user operation;
Performing an edge detection process on the set region of the image;
Setting a value for correcting the position of the detected edge point;
Correcting the position of the detected edge based on the value;
A control method comprising the step of calculating the value indicated by the pointer of the meter according to the position of the corrected edge point. On the computer
Acquiring an image of the instrument taken by the imaging device;
Setting an area to be subjected to edge detection processing in the image in response to a user operation;
Performing an edge detection process on the set region of the image;
Setting a value for correcting the position of the detected edge point;
Correcting the position of the detected edge based on the value;
A program that executes a step of calculating a value indicated by a pointer of an instrument according to the position of the corrected edge point.

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