JP2024012889A - Character string reading method, character string reading device and program - Google Patents

Abstract

To enable a user to experience use feeling close to a function of a regular version while allowing the user to indefinitely try the function in the case that the user is provided with the function for identifying a character string in an image of a reading object.SOLUTION: An imaging part 151 acquires an image of a reading object, a character string identification part 153 identifies a character string in the acquired image, and an output part 155 outputs the character string. At that time, a character conversion part 154 converts a part of characters selected from in the character string identified by the character string identification part 153 into a character for a predetermined mask before an output from the output part 155. At that time, the character string identification part 153 may redetermine what number character in the identified character string is selected as the part of characters each time the character string is identified. Also, character selection is performed at random.SELECTED DRAWING: Figure 2

Description

The present invention provides a character string reading method in which an image of an object to be read is acquired by an image acquisition unit and a character string in the acquired image is read, a character string reading device for reading such a character string, and a computer as described above. This invention relates to a program for executing a character string reading method.

Conventionally, in optical information reading devices for optically reading code symbols such as barcodes and two-dimensional codes, it has been necessary to take an image of an object to be read, cut out the code symbol from the image obtained by imaging, and decode it. is being carried out.
Further, Patent Document 1 describes an OCR (Optical Character Recognition) software that reads character strings in images obtained by imaging by installing OCR (Optical Character Recognition) software in such an optical information reading device. It is also stated that the function is provided.

In addition, in relation to OCR, Patent Document 2 states that when a character string resulting from character recognition on an image obtained by reading a document contains specific syntactic features, An unauthorized reading prevention device that prohibits reading is described.

Patent No. 5637995 (especially paragraph 0037) Japanese Patent Application Publication No. 2001-291053

By the way, the above-mentioned OCR function may be installed as an optional additional function to increase the added value of the optical information reading device. For example, a model equipped with an OCR function may be sold as a high-end model, or the OCR function may be provided as an optional additional function for a fee.
When such a product lineup is provided, there is a demand for easy trial use in order to allow users to decide whether to purchase a high-end model or additional functions.

However, for example, if you enable the OCR function for a certain period of time for trial use, and then disable the use of the OCR function at all after that period, users who are unable to complete the evaluation of the function within that period can try again. There was a problem that it was a hassle to have them do it. This is because if unlimited retrials are allowed, the OCR function will essentially be used free of charge, so it will be necessary to manage the trial period and number of trials.
The technology described in Patent Document 2 that prohibits document reading under specific conditions is also not focused on such trial use.

The present invention solves such problems and provides a function for identifying character strings in an image of an object to be read to a user, while allowing the user to use the function indefinitely. The purpose is to allow users to experience a usability that is close to the functionality of the official version.
Note that the above problem is the same, although there are differences in degree, even when the function to identify character strings is provided as a stand-alone function rather than as an additional function, and when an image of the object to be read is acquired by means other than imaging. This invention is applicable to these cases as well.

In order to achieve the above object, the character string reading method of the present invention acquires an image of an object to be read by an image acquisition unit, identifies a character string in the acquired image, and outputs data of the character string. and a conversion procedure for converting some characters selected from the character string identified in the identification procedure into predetermined masking characters before the output.

In such a character string reading method, each time a character string is identified in the above identification step, the number of characters in the identified character string to be selected as the part of the characters in the above conversion step is determined again. Good.
Alternatively, in the conversion procedure, some of the characters may be randomly selected from the identified character string.
Alternatively, the above identification step is a step of identifying a character string in the acquired image according to a predetermined character string format, and the masking character does not appear in the character string according to the above format. Preferably in text.

Alternatively, when the above character string reading method is executed by a character string reading device that reads a character string attached to an object, and a predetermined input is given to the character string reading device, after that input, the above It is preferable to include an invalidation procedure for controlling the character string reading device so as not to perform the conversion procedure.
Furthermore, the character string reading device is capable of executing a decoding procedure for decoding code symbols in the acquired image, and the predetermined input is an object from which a predetermined character string can be obtained by decoding in the decoding procedure. It is preferable that the image acquisition unit acquires an image of the object.

Furthermore, in addition to being implemented in the method described above, the present invention can be implemented in any other manner such as an apparatus, a system, a program, a recording medium on which a program is recorded.

According to the configuration of the present invention as described above, when providing a user with a function to identify a character string in an image of an object to be read, the user can use the function indefinitely, and Users can experience a usability that is close to the functionality of the official version.

1 is a block diagram showing the hardware configuration of a reading device 100, which is an embodiment of a character string reading device of the present invention. FIG. 2 is a functional block diagram showing the configuration of functions included in the reading device 100 shown in FIG. 1. FIG. 3 is a diagram showing an example of a reading target 101. FIG. 4 is a diagram showing an example of a reading result of the reading target shown in FIG. 3 by the reading device 100. FIG. It is a flowchart of the process executed by the CPU 121 of the reading device 100 when the character reading mode is turned on. It is a flowchart of the process executed by the CPU 121 of the reading device 100 when the code reading mode is turned on.

Embodiments of the invention will be described with reference to the drawings.
First, an embodiment of a character string reading device of the present invention will be described using FIG. FIG. 1 is a block diagram showing the hardware configuration of a reading device that is an embodiment of a character string reading device.
The reading device 100 shown in FIG. 1 is a device for optically reading a character string 102 on a reading object 101 whose light reflectance is different from the surroundings, and is also an imaging device that takes an image of the reading object 101 during the reading. be. Further, the reading device 100 has a function as an optical information reading device for optically reading a code symbol 103 on the reading target 101, which is indicated by a symbol having a different light reflectance from the surroundings.

The reading target 101 may be a record carrier that statically holds a character string 102 or a code symbol 103, or may be a display device that dynamically displays a code symbol. The format of the character string may be predetermined, but the position and number of characters in the character string may also be recognized during character string recognition, which will be described later. The code symbol 103 may also be a one-dimensional bar code or a two-dimensional code, and its standard does not matter. The configuration may be such that the standard is not specified in advance and the standard is determined during decoding processing, which will be described later.

As shown in FIG. 1, this reading device 100 includes an optical section 110, a control section 120, an operation section 131, a notification section 132, and a display section 133.
Among these, the optical section 110 includes an image sensor 111, a lens 112, and a pulsed LED (light emitting diode) 113, and is an imaging device for optically capturing an image of a reading target 101 including a character string 102 and/or a code symbol 103. It is a device.

The imaging sensor 111 is an imaging unit for capturing an image of an imaging target such as the reading target 101, and can be configured by, for example, a CMOS (complementary metal oxide semiconductor) image sensor. Further, the image sensor 111 can generate image data indicating the gradation value of each pixel based on the charge accumulated in each pixel of the image sensor by imaging, and output it to the control unit 120. In this image sensor 111, pixels are arranged two-dimensionally.

The lens 112 is an optical system for forming an image of reflected light from the imaging target on the image sensor 111.
The pulse LED 113 is an illumination unit for irradiating illumination light onto an object to be imaged by the image sensor 111.

Next, the control unit 120 communicates with the CPU 121, a ROM 122 that stores data such as programs executed by the CPU 121 and various tables, a RAM 123 used as a work area when the CPU 121 executes various processes, and an external device. It is equipped with a communication I/F 124 for performing.

The CPU 121 controls the entire operation of the reading device 100 including the optical section 110, the operation section 131, the notification section 132, and the display section 133 by executing a program stored in the ROM 122 using the RAM 123 as a work area. is used to realize various functions, including those described below. This function includes identification of the character string 102 included in the image data of the image captured by the image sensor 111, partial masking and display of the identification result, output or storage to the outside, activation of the character reading function, etc. Processing may be included.
The communication I/F 124 is an interface for communicating with various external devices such as a data processing device that uses the identification result of the character string 102.

The operation unit 131 is an operation means such as a button or a trigger for accepting user operations. The notification unit 132 is a notification means for giving various notifications to the user. Specific notification methods include, but are not limited to, displaying a message or data on a display, lighting or blinking a lamp, and outputting sound from a speaker. The display unit 133 is a display means for displaying the character string identified by the reading device 100, and can be configured with a liquid crystal display or the like. The notification unit 132 and the display unit 133 may be made of common hardware.

When the reading device 100 is automatically operated under control from an external device or autonomously, the operation section 131, the notification section 132, and the display section 133 may not be provided.
The reading device 100 described above can be configured, for example, as a hand-held or stationary type code symbol reading device with a character reading function, but is not limited thereto. A general-purpose computer such as a smartphone or a personal computer may be used as all or part of the hardware.

One of the characteristics of the reading device 100 described above is the method of restricting the use of the character reading function. Next, this point will be explained.
First, functions related to reading the character string 102, including the above-mentioned usage restriction function, provided in the reading device 100 will be described. At the same time, functions related to reading the code symbol 103 will also be explained.
FIG. 2 is a functional block diagram showing the configuration of its functions.

As shown in FIG. 2, the reading device 100 includes the functions of an imaging section 151, a decoding section 152, a character string identification section 153, a character conversion section 154, an output section 155, a release trigger detection section 156, and an invalidation section 157. In the example described here, the functions of each of these parts are realized by the CPU 121 controlling each part of the reading device 100 including the optical part 110 by executing software. It may be realized by a control circuit.

The imaging unit 151 shown in FIG. 2 has a function of controlling the optical unit 110 to perform imaging and acquiring image data obtained by imaging. Further, depending on the reading mode of the reading device 100, if the character reading mode for reading the character string 102 is ON, the acquired image data is passed to the character string identification section 153, and if the code reading mode for reading the code symbol 103 is ON, the acquired image data is passed to the character string identification section 153. For example, the acquired image data is passed to the decoding section 152. These may be turned on at the same time. Further, appropriate imaging conditions may be determined according to a known method as appropriate.

The decoding unit 152 decodes the code symbol 103 included in the image data passed from the imaging unit 151, and when the decoding is successful, outputs the fact and the decoding result data to the output unit 155 and the release trigger detection unit 156. Equipped with a function to pass. For this decoding process, a publicly known method can be adopted as appropriate. The decoding result may be processed in some way before being passed to the output unit 155.

The character string identification unit 153 identifies a character string included in the image indicated by the image data passed from the imaging unit 151, generates data of the character string, and passes it to the character conversion unit 154 and the release trigger detection unit 156. Equipped with functions. The character string identification method can be realized by appropriately employing known OCR technology. In the end, the specific recognition method does not matter as long as the data of the character string to be output from among the character strings included in the image can be obtained. As will be described later with reference to FIG. 3, it is not essential to output data for all character strings included in the image.

The character conversion unit 154 has a function of converting some characters selected from the character string passed from the character string identification unit 153 into predetermined masking characters and passing the converted characters to the output unit 155. The character to be selected is at least one character, but may be a plurality of characters. The character conversion by the character conversion unit 154 is performed by masking and outputting a part of the identification result by the character string identification unit 153, so that the user can confirm most of the identification result, and the output data can be used. This is done to make it virtually impossible to do so. This function is provided to partially limit the character reading mode functions of the reading device 100 and allow the user to try it out. A specific example and concept of character conversion by the character conversion unit 154 will be described later using FIGS. 3 and 4.

The output unit 155 uses the communication I/F 124 and the notification unit 132 to output the decoding result data passed from the decoding unit 152 and the character string data passed from the character conversion unit 154 to an external device such as a data processing device. It also has the function of notifying the user of successful reading. The user can be notified by any method such as a buzzer or vibration, and the notification does not have to be performed if the notification is not required. The output unit 155 also has a function of displaying the decoding result passed from the decoding unit 152 and the character string passed from the character conversion unit 154 on the display unit 133.

The release trigger detection unit 156 has a function of detecting a specific input that becomes a trigger for releasing the functional restriction of the character reading mode. In this embodiment, the trigger is that a specific character string is included in the decoding result by the decoding unit 152 (for the reading device 100 to read the code symbol 103 from which such a decoding result is obtained), and the character string identification. A specific character string is included in the character string identified by the unit 153 (the reading device 100 is caused to read the character string 102 from which such an identification result is obtained). The release trigger detection unit 156 determines the presence or absence of a trigger based on the decoding result passed from the decoding unit 152 and the identification result passed from the character string identification unit 153, and when a trigger is detected, notifies the invalidation unit 157 to that effect. Notice.

The disabling unit 157 has a function of disabling the function of the character converting unit 154 from then on when there is a notification of trigger detection from the release trigger detecting unit 156. This invalidation may be irreversible, but it may be possible to enable it again later in response to some trigger. When the function of the character conversion section 154 is disabled, the character string data resulting from the identification by the character string identification section 153 is supplied as is to the output section 155, where it is output, displayed, etc. In other words, the functions of the character reading mode can be used without restrictions.
Among the above units, the imaging unit 151, character string identification unit 153, and output unit 155 correspond to the identification unit, and the character conversion unit 154 corresponds to the conversion unit.

Next, a specific example and concept of character conversion by the character conversion unit 154 will be described using FIGS. 3 and 4. FIG. 3 schematically shows, as an example of the reading object 101, a page of a Japanese passport in which the information of the holder is written. FIG. 4 is a diagram showing an example of a reading result of the reading target shown in FIG. 3 by the reading device 100.
The reading device 100 can read a reading target as shown in FIG. 3 and recognize character strings contained therein. At this time, all character strings may be recognized, but it is also possible, for example, to read only the character strings in the area 200 indicated by broken lines.

Here, in a Japanese passport, a character string of 44 characters x 2 lines is normally written in an area 200 indicated by a broken line. Therefore, by setting this format in the reading device 100 in advance and having the character string identification section 153 identify only character strings that match this format, it is possible to identify only the character strings within the area 200. A method is already known in which the accuracy of character string recognition is improved by specifying the format of a character string in advance.

When the page of FIG. 3 is read by the reading device 100 with the character reading mode set to ON with the format specified in this way, the result of character string identification by the character string identification unit 153 is that the identification is normal. If this is done, the character string 230 at the bottom of FIG. 4 will be obtained.
However, if the function of the character conversion unit 154 is effective, some characters selected from the character string 230 are actually converted into predetermined mask characters, and, for example, the character string 210 is output. . In the character string 210, the character "K" at the position indicated by the reference numeral 211 has been converted to a masking character "?". Note that hereinafter, converting characters included in the identification results into characters for masking will also be referred to as "masking."

When such a conversion is performed, the actually output character string (data) is different from the character string 102 written in the reading target 101, so it is unsuitable for use as a reading result in other processing. . However, by comparing the displayed or output character string with the character string 102, it can be easily understood that character recognition is performed appropriately at positions other than the position indicated by the reference numeral 211. Furthermore, the time required for reading and the operating feel are substantially the same as the official version described below. Therefore, it can be said that the operation is sufficient for trial use of the character reading mode.

Note that it is preferable that the character string identification section 153 re-determines which character position (number in the identification result) the character conversion section 154 selects each time a character string is identified. By doing this, when the character string 210 is output on the first reading, in the character string 220 that is output when the same page is read again, the character "4" indicated by the code 221 is in a different position than the first time. , can be converted to the masking character "?".

As a result, while maintaining the state in which the output character string is unsuitable for use in other processing as a reading result, the character at the position indicated by the symbol 211 that was masked in the first reading is also properly corrected. You can confirm that it can be identified. Furthermore, during trial use, it is normal to read the product many times to confirm accuracy and usability, so the fact that two readings are required for confirmation is not a problem. On the other hand, in actual field operations, if the correct reading result cannot be obtained unless reading is performed twice each time, the operability deteriorates significantly, making it virtually unusable in the actual field. I can say it.

Such an effect can only be obtained if the position selection algorithm by the character conversion unit 154 is "always the same position" (selections that are determined to be the same position each time are not "re-determined"). (Not considered applicable). That is, it does not matter if the selection is random or a regular algorithm such as shifting one character at a time. However, random selection is preferable from the viewpoint of versatility because it can be used regardless of the format of the character string to be identified and can be applied even when selecting characters at any number of locations. In addition, with random selection, it is impossible to predict which characters will be masked, so it is preferable from the viewpoint of maintaining a state in which the output character string is unsuitable for use in other processing as a reading result. .

Here, only one character of the character string identified by the character string identification unit 153 is masked, but a plurality of characters may be masked. In particular, if the length of the character string to be identified is long, masking only one character may not be sufficient to ensure that the output character string is unsuitable for use in other processing as a reading result. There is sex. In such cases, it is recommended to increase the number of characters to be masked. However, if you increase the number too much, it will become difficult to understand whether character recognition is being performed appropriately as a whole, so it is better to take this point into consideration when deciding how many characters to mask. Based on the number of identified characters, the number of characters to be masked may be determined by multiplying by a specific ratio.

Note that the masking characters are preferably characters that are not included in the character string identified by the character string identification unit 153, but from the user's point of view of the reading device 100, it is possible that the characters are not the result of identification. It's enough if you understand. For example, it may be a character such as "#" that does not appear often in normal sentences. If a symbol or the like is specified to indicate a location where characters could not be identified, the masking characters shall be different from the symbol, etc.

Furthermore, regarding the format of the character string to be identified, by specifying in advance not only the number and arrangement of characters, but also the types of characters that can be included in the character string, it is possible to further improve the accuracy of character string recognition. is also known. In the example of a passport, the character strings that may be used are limited to numbers, alphanumeric characters, and some symbols such as "<", so it is conceivable to specify these characters in advance.

In this case, it is preferable to use characters that do not appear in the character string according to the specified format as mask characters because the user of the reading device 100 can easily determine that the characters are not the result of identification. The "?" shown in FIG. 4 is determined using this method.
It is also possible to prepare a plurality of characters for masks and use them randomly or according to a predetermined rule. For example, the first masking character is used for a character string identified one time, the second masking character is used for a character string identified the next time, and so on. It is also conceivable to use the first masking character and the second masking character depending on the vertical position of the character to be converted for a character string identified at a particular time.

As described above, when the function of the character conversion unit 154 is in an effective state, the character reading mode cannot be used substantially for business purposes and can only be used on a trial basis. Therefore, even if users are allowed to use the character reading mode without specifying the period or number of times, it is thought that there will be no negative impact on sales of the character reading mode as an additional function or sales of high-end models equipped with the character reading mode.
Furthermore, by disabling the function of the character conversion section 154 using the functions of the release trigger detection section 156 and the disabling section 157, the function of the character reading mode can be operated normally, and the unmasked characters can be displayed as a reading result. Column 230 may be output. That is, it is possible to end the trial state and activate the character reading mode function as a regular version.

In this embodiment, the device can be activated by having the reading device 100 read a specific character string (activation code) in the form of a code symbol or character string. Therefore, there is no need to provide an interface on the reading device 100 for the user to manually input the code, or to prepare an application for code input on the computer connected to the reading device 100, resulting in low cost and easy operation. Activation is possible.
A timekeeping function is also not required for activation management. Dedicated code symbol reading devices may not be provided with a timekeeping function from the perspective of reducing hardware costs, but the method described here can also be applied to such devices.
The activation code is set in the reading device 100 in advance. It may be determined for each individual reading device 100, but it may be determined for each purchaser or other criteria.

In addition to the method described above, in order to realize a state in which the output character string is unsuitable for use in other processing as a reading result, the character conversion unit 154 randomly converts the characters at the selected position. It is also possible to convert it to other characters. However, when doing this, there is a problem in that it is difficult for the user to understand whether or not the conversion has been performed, especially when the output character string is long. If the user uses the system for work without realizing that the conversion is being performed and realizes that the converted part has been misread, this is undesirable because it will lead to a loss of confidence in the character reading mode. In order to avoid such a problem, it is preferable to replace it with a masking character string as described above.

It is also conceivable to replace a specific character (for example, "A" or "1") in the character string identified by the character string identification unit 153 with a masking character. However, in this case, by inversely converting the masking characters into the specific characters, even if the character string is output when the character conversion unit 154 is enabled, it can be easily converted into a character string that can be used for other processing. This means that it can be converted to . In this case, there is a possibility that the character reading mode can be effectively used without activation, which is not preferable.

However, if, for example, a randomly selected character from a character string identified by the character string identification unit 153 is to be replaced with a masking character string, reverse conversion is not easy. You can expect good results. However, if the randomly selected character does not appear in the identified character string, you will not know that the conversion is occurring, so in this respect, it is important to select the vertically selected character that will definitely be converted. Replacement processing is preferable.

Next, processing for realizing the functions described above will be described using FIGS. 5 and 6. The process described here is an embodiment of the character string reading method of the present invention.
First, FIG. 5 shows a flowchart of the process that the CPU 121 executes when the character reading mode is turned on.

In this process, the CPU 121 first waits until a reading start trigger is detected (S11). As this trigger, for example, an operation of the operation unit 131 by the user or a signal transmitted from an external device connected to the communication I/F 124 can be used.
When the trigger is detected, the CPU 121 controls the optical section 110 to take an image, obtains image data (S12), and identifies the character string in the image data (S13). The process in step S12 corresponds to the function of the imaging unit 151, and the process in step S13 corresponds to the function of the character string identification unit 153.

In step S12, if an image of the reading target 101 including the character string 102 suitable as an identification target is captured with appropriate brightness and focus, it is considered that the identification is successful. If the CPU 121 determines that the identification is successful (Yes in S14), the process proceeds to step S15 and subsequent steps. If the identification has failed (No in S14), the CPU 121 returns to step S12 and repeats the process. At this time, imaging conditions such as illumination amount, exposure, and gain may be adjusted as appropriate.

In step S15, the CPU 121 determines whether the character reading mode has been activated. If Yes here means that the function of the character conversion unit 154 is disabled, so the CPU 121 displays and outputs the character string identified in step S13 as it is (S16, S17), and once The processing related to the reading of is completed, and the process returns to step S11.

On the other hand, if No in step S15, the CPU 121 determines whether or not the character string identified in step S13 includes a predetermined activation code (S18). If No here as well, as explained using FIGS. 3 and 4, the CPU 121 selects which character in the character string identified in step S13 is to be masked (S19), and the selected The characters are converted into characters for masking (S20). The processing in steps S19 and S20 corresponds to the function of the character conversion unit 154.
Thereafter, the CPU 121 displays and outputs the converted character string (S21, S22), completes the process related to one reading, and returns to step S11.

Further, if Yes in step S18, the CPU 121 disables the function of the character conversion unit 154 and activates the character reading mode (S23), and notifies the user of this through the notification unit 132 or the like (S24), Return to step S11. In this case, there is no need to display or output the string.
In the above process of FIG. 5, the processes of steps S12, S13, S16, and S17 correspond to the process of the identification procedure. The processing of steps S19 and S20 corresponds to the processing of the conversion procedure. The process of step S23 corresponds to the process of the invalidation procedure.

Next, FIG. 6 shows a flowchart of the process that the CPU 121 executes when the code reading mode is turned on.
In this process, as in steps S11 to S14, when the CPU 121 detects a trigger to start reading (Yes in S31), the CPU 121 controls the optical section 110 to capture an image (S32), and captures the obtained image data. The decoding (S33) is repeated until the decoding is successful (S34). The process in step S33 differs from step S13 in FIG. 5 and corresponds to the function of the decoding unit 152.

If the decoding is successful, the CPU 121 determines whether the character reading mode has been activated (S35). If Yes here, there is no need to make a determination regarding activation, so the CPU 121 displays and outputs the character string decoded in step S33 (S36, S37), and ends the process related to one reading, Return to step S31.
If No in step S35, the CPU 121 determines whether the character string decoded in step S33 includes a predetermined activation code (S38). If No here as well, the CPU 121 proceeds to step S36 without performing activation.

If Yes in step S38, the CPU 121 disables the function of the character conversion unit 154 and activates the character reading mode (S39), notifies the user of this through the notification unit 132 or the like (S40), and performs step S31. Return to In this case, there is no need to display or output the string.
In the above process of FIG. 6, the process of step S39 corresponds to the process of the invalidation procedure.
In the reading device 100, the CPU 121 executes the processes shown in FIGS. 5 and 6 to realize each function described using FIG. 2 and execute the operations described using FIGS. 3 and 4. be able to.

[Modified example]
This concludes the description of the embodiment, but in this invention, the specific configuration of the device, specific processing procedure, data format, specific data content, format of the character string to be read, etc. It is not limited to what is explained in.
For example, as an activation method, it is not necessary to use input by reading a code symbol and input by reading a character string in combination; either one may be used. Further, any method other than these may be used.

Furthermore, it is not essential to provide the reading device 100 with an activation function. Devices and programs equipped with the character conversion unit 154 function are for trial use only, and customers who have purchased the character reading function are provided with a separate device without the character conversion unit 154 or a program from which the character conversion unit 154 function is removed. It is also conceivable to provide a program and install it on the reading device 100 to replace the trial program that includes the function of the character converter 154.
Note that if there is a genuine program that does not include the character conversion section 154, a program for trial use can be easily created by adding the function of the character conversion section 154 to this program.

Further, it is not essential to acquire the image of the reading target 101 by imaging. Whether the image is acquired by scanning using a flatbed scanner, a handy scanner that slides over the object by hand, or by any other method. , the embodiments described above are applicable.

Furthermore, in the embodiment described above, some characters selected from the character string identified from the acquired image were masked, but the same thing can be applied to the character string obtained by decoding the code symbol in the image. It is also possible. In this way, the code reading mode can also be used on a trial basis as explained using FIGS. 3 and 4. In the case of code symbols, by comparing the code symbol itself and the output string, it is difficult to determine whether decoding is being performed correctly in areas other than the masked portions. However, for example, if the character string coded by the code symbol 103 is written in the reading target 101 alongside the code symbol 103, it is easy to determine whether or not decoding is being performed correctly.

Furthermore, the same idea can be applied even when outputting something other than character strings. A character string identified from an image can be considered to be vector data having elements equal to the number of characters, especially when the number of characters in the character string is specified by the format. The selection of which character in the character string to mask, as described in the above embodiment, can be considered to be the selection of which element in vector data to mask.
Then, when trying out a function that outputs arbitrary processing results as vector data, some elements selected from the vector data will be converted to predetermined mask data before output. , the embodiments described above can be extended.

Examples of this vector data include the length, width, and height, which are the measured or estimated sizes of a substantially rectangular parallelepiped object, and the measured position and acceleration of the object in a three-dimensional space. By re-determining which element to mask for each measurement (result output), even if some data is masked each time, the user can easily perform multiple measurements over time. By referring to the output, it is possible to confirm whether generally correct data is being output for all items.

Furthermore, image data can also be considered to be vector data having elements equal to the number of pixels, with the pixel value of each pixel as an element. In this case, the above-described embodiment is modified so that, for example, before outputting image data obtained by shooting, etc., some elements (pixels) selected from the image data are replaced with pixel values for a specific mask. It is possible. This replacement may be used, for example, when a high-resolution image output function is prepared as an option for trial use. Even if some pixels are masked, the user can visually confirm the effect of higher resolution in the unmasked areas, but the image contains pixels whose colors have been replaced (for example, randomly). cannot withstand normal viewing.

In addition, in the embodiment described above, the vector data may be changed so that the length of the identified character string may change for each identification (it is not essential to identify a character string in a specific format). In this case as well, the number of elements of vector data output may vary each time a result is output.

Further, the embodiment of the program of the present invention allows one computer or a plurality of computers to work together to control necessary hardware and realize the functions of the reading device 100 in the embodiment described above, or This is a program for executing the processing described in the embodiment.

Such a program may be stored in a ROM or other nonvolatile storage medium (flash memory, EEPROM, etc.) provided in the computer from the beginning. It can also be provided by being recorded on any nonvolatile recording medium such as a memory card, CD, DVD, or Blu-ray disc. Furthermore, it is also possible to download it from an external device connected to a network, install it on a computer, and run it.

Furthermore, it goes without saying that the configurations of the embodiments and modified examples described above can be implemented in any combination as long as they do not contradict each other, or only a part of them can be extracted and implemented.

DESCRIPTION OF SYMBOLS 100... Reading device, 101... Reading object, 102... Character string, 103... Code symbol, 110... Optical part, 111... Image sensor, 112... Lens, 113... Pulse LED, 120... Control part, 151... Imaging part, 152 ...Decoding section, 153...Character string identification section, 154...Character conversion section, 155...Output section, 156...Cancellation trigger detection section, 157...Disabling section

Claims (13)

an identification procedure of acquiring an image of the object to be read by an image acquisition unit, identifying a character string in the acquired image, and outputting data of the character string;
A conversion step of converting some characters selected from the character string identified in the identification step into predetermined masking characters before the output. . The character string reading method according to claim 1,
A character string reading method, characterized in that in the conversion step, the number of characters in the identified character string to be selected as the part of characters is determined each time a character string is identified in the identification step. Method. The character string reading method according to claim 1,
A method for reading a character string, characterized in that, in the conversion step, some of the characters are randomly selected from the identified character string. The character string reading method according to claim 1,
The identification procedure is a procedure for identifying a character string in the acquired image according to a predetermined character string format,
A character string reading method, wherein the masking character is a character that does not appear in a character string according to the format. The character string reading method according to claim 1,
Executed by a character string reader that reads the character string attached to the object,
The character string reading device is characterized by comprising an invalidation procedure for controlling the character string reading device so that, when a predetermined input is given to the character string reading device, the conversion procedure is not performed after the input. Column reading method. The character string reading method according to claim 5,
The character string reading device is capable of executing a decoding procedure for decoding code symbols in the acquired image,
The character string reading method, wherein the predetermined input is to cause the image acquisition unit to acquire an image of the object from which a predetermined character string can be obtained by decoding in the decoding procedure. an identification unit that acquires an image of the object to be read by an image acquisition unit, identifies a character string in the acquired image, and outputs data of the character string;
A character string reading device, comprising: a conversion unit that converts some characters selected from the character string identified by the identification unit into predetermined masking characters before the output. . The character string reading device according to claim 7,
Character string reading, characterized in that the conversion unit re-determines which character in the identified character string to select as the part of characters each time the identification unit identifies a character string. Device. The character string reading device according to claim 7,
A character string reading device, characterized in that some of the characters are selected at random. The character string reading device according to claim 7,
The identification unit identifies a character string in the acquired image according to a predetermined character string format,
A character string reading device, wherein the masking character is a character that does not appear in a character string according to the format. The character string reading device according to any one of claims 7 to 10,
A character string reading device, comprising: an invalidating section that invalidates the converting section after the input when a predetermined input is given. The character string reading device according to claim 11,
comprising a decoding unit that decodes code symbols in the image of the object to be read acquired by the image acquisition unit,
The character string reading device, wherein the predetermined input is to cause the image acquisition unit to acquire an image of the object to be read that can be decoded by the decoding unit to obtain a predetermined character string. A program for causing a processor that controls the image acquisition unit to execute the character string reading method according to any one of claims 1 to 6.

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