Method and device for modifying form data on electronic file

Abstract

The present invention relates to a method for modifying form data on an electronic file, the method comprising: generating a form signature modification interface for the electronic file; the form signature modification interface comprising an interactive interface for inputting signature modification parameters; receiving signature modification parameters through the form signature modification interface, the signature modification parameters comprising at least one of a modifier's digital certificate, the modifier's name or stamp image, digital signature appearance parameters and signature method, form fields to be modified and their modified new values, modification reasons, and modification time; and stamping the electronic file with a digital signature using the received signature modification parameters. The method of the present invention can achieve the effect of modifying or adding data to form fields that have been protected by approval signatures in electronic files, while maintaining the validity of previous form field data filling and approval signatures.

Description

Technical Field

[0001] The present invention relates to electronic file processing technology, and in particular to a method and device for modifying form data on an electronic file. Background Art

[0002] Electronic document processing systems often involve business processing based on electronic documents. Business generally refers to matters that need to be processed in various industries. For example, a business can be described by a business form of a layout file; a layout file can be an electronic document such as a leave application, reimbursement form, loan form, official document, contract, doctor's prescription and patient medical record, which can contain multiple form fields that need to be filled in and multiple approvers' approval signatures.

[0003] In the process of electronic document processing, the certification signature is used to explain the source and purpose of the electronic document; the approval signature is used to record the approval process and traces of the electronic document. The approval signature can include the signatures of the personnel involved in the business process. The approval signature protects the form fields in the file by locking specific form fields; however, once the form field is protected by the approval signature, the value of the form field cannot be modified (except for hacker tools). Even if it is illegally modified, it will cause the approval signature to become invalid.

[0004] However, in many cases, the form field data in electronic files needs to be modified. For example, in one case, after the business form in the electronic file has been approved level by level, it is found that the value of the secondary form field of a form field is incorrect. Traditional paper documents allow the editor to smudge and mark the form field that needs to be modified, modify the content next to it and sign the explanation, and still continue the business processing and approval process. In electronic files, because the form fields of the business form have been locked and cannot be modified, the result is that the electronic file can only be discarded and the business form data must be filled in and approved again according to the business process, which greatly wastes manpower and material resources.

[0005] There is another situation where the filling and approval process of the business form of the electronic file is halfway through, or in the process of being processed, and the management department issues new regulations at this time, requiring the new business to use the new form, and the business being processed to use the old form, but requiring signatures on the form for additional explanations. The only result is to discard the electronic file and fill in and approve the business form data again according to the new business regulations, which means that the previous data filling and approval must be discarded and started over. Summary of the invention

[0006] The object of the present invention is to provide a method and apparatus for modifying form data on an electronic document, so as to overcome at least one of the above-mentioned defects existing in the prior art.

[0007] The present invention provides a method for modifying form data on an electronic file, wherein the electronic file includes a form field and a form signature field, and the method includes: generating a form signature modification interface for the electronic file; wherein the form signature modification interface includes an interactive interface for inputting signature modification parameters; receiving signature modification parameters through the form signature modification interface, wherein the signature modification parameters include at least one of a modifier's digital certificate, a modifier's name or a stamp image, digital signature appearance parameters and a signing method, form fields to be modified and their modified new values, modification reasons, and modification time; and stamping a digital signature on the electronic file using the received signature modification parameters.

[0008] In some embodiments, the method for modifying form data also includes: writing the modifier's public key digital certificate, signature opinion, signature time and signature method, as well as all modified form fields and their new modified values ​​into the digital signature dictionary of the electronic file; wherein the modification time is used as the signature time, and the modification reason is used as the signature opinion.

[0009] In some embodiments, the method for modifying form data also includes: using the received signature modification parameters to generate a signature appearance for presenting a visual effect appearance of the final digital signature on an electronic file; wherein the signature appearance indicates the name of the modified form field and its modified new value, the name or stamp image of the modifier, the reason for the modification and the modification time; and writing the signature appearance into the electronic file.

[0010] In some embodiments, the signature appearance further includes a pointing mark pointing to the modified form field in the electronic file.

[0011] In some embodiments, the signature appearance indicates the names of multiple modified form fields and their modified new values.

[0012] In some embodiments, the method for modifying form data further includes: when it is determined that the electronic file does not contain the form field that needs to be modified, adding the form field containing the modified new value to the electronic file.

[0013] In some embodiments, multiple modifications are allowed to the form fields in the electronic file, wherein the method for modifying the form data further comprises: extracting a new modified value of the form field modified last time as final form data of the modified form field.

[0014] In some embodiments, the electronic file is a layout file.

[0015] The present invention also provides a device for modifying form data on an electronic file, wherein the electronic file includes a form field and a form signature field, and the device includes: a form signature modification interface generation module, used to generate a form signature modification interface for the electronic file; wherein the form signature modification interface includes an interactive interface for inputting signature modification parameters; a signature modification parameter receiving module, used to receive signature modification parameters through the form signature modification interface, wherein the signature modification parameters include at least one of the modifier's digital certificate, the modifier's name or impression image, digital signature appearance parameters and signing method, form fields to be modified and their modified new values, modification reasons, and modification time; and a digital signature stamping module, used to stamp a digital signature on the electronic file using the received signature modification parameters.

[0016] The present invention also provides a device, comprising: a memory for storing instructions; and a processor coupled to the memory, wherein when the instructions are executed by the processor, the processor executes the form data modification method according to any one of the above embodiments.

[0017] The present invention also provides a computer-readable storage medium storing instructions, which, when executed by a processor of a computer, enable the processor to execute the form data modification method according to any one of the above embodiments.

[0018] The technical effects achieved by the above technical solution of the present invention include but are not limited to: data modification can be performed on form fields in electronic files that have been protected by approval signatures, and new form fields can be added to electronic files. These modifications will not invalidate the previous form field data filling and approval signatures, and the business processing flow can continue, thereby improving the efficiency of business processing using electronic files. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flowchart showing a method for modifying form data on an electronic document according to an embodiment of the present invention;

[0020] Figure 2 A block diagram showing the composition of the modified signature element in the embodiment;

[0021] Figure 3 A partial example of a modified layout file in the embodiment is shown, in which the form field "experimental drug" is modified and adopts a directional signature appearance;

[0022] Figure 4 An operation flow chart showing modification of a form field in an embodiment is shown;

[0023] Figure 5A partial example of a modified format file in the embodiment is shown, in which a non-directional signature appearance is adopted, and a newly added form field "medication time" is indicated in the signature appearance;

[0024] Figure 6 A flowchart showing the operation of adding a new form field in an embodiment is shown;

[0025] Figure 7 A schematic diagram showing program modules of a business processing system used in an embodiment. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0027] The electronic file processed in the embodiment of the present invention can be a layout file or an electronic document file in other formats. The layout presentation effect of the layout file is fixed in the electronic document format. The presentation of the layout document is independent of the device used. When reading, printing or printing on various devices, the presentation results of the layout are consistent. Such as international standard PDF files, national standard OFD files, etc. PDF files are file formats developed by Adobe Systems for file exchange in a way that is independent of applications, operating systems, and hardware. The appearance, business logic, form field properties and storage of form data of the form can be defined in the layout file. After the layout file form is designed, the form structure is fixed in the filling mode, and only the form field is provided for input. With the help of the layout solidification characteristics of the layout file and the dynamic interaction characteristics of the form business, the traditional paper form filling can be simulated to a large extent.

[0028] By adding a certification signature to a layout file, you can solidify the layout file's source, purpose, document permissions, form appearance, form business logic, etc. If the above information is modified, it means that the layout file is not recognized by the certification party. A layout file can usually only have one certification signature.

[0029] Approval signature is also called approval signature. By signing the electronic document, part of the form field is locked and read-only, and the person who approved, time, location (host information), comments, contact information and other information are recorded. If the file version protected by the approval signature is modified by binary or the protected form field is modified, the approval signature verification fails. The signature of the modifier is also an approval signature.

[0030] According to an embodiment of the present invention, Figure 1As shown, the method for modifying form data on an electronic file includes: generating a form signature modification interface for the electronic file (step 101); the form signature modification interface includes an interactive interface (such as a dialog box) for inputting signature modification parameters; receiving signature modification parameters through the form signature modification interface (step 102); the signature modification parameters include a modifier's digital certificate, a modifier's name or stamp image, digital signature appearance parameters (such as the font and size of the signature) and a signature method, a form field to be modified and its modified new value, a modification reason, and at least one of the modification time; and stamping the electronic file with a digital signature using the modifier's digital certificate (step 103).

[0031] According to an embodiment of the present invention, a form signature modification interface is used to receive form modification data or add new form data, without directly modifying the data in the form field, thereby maintaining the validity of the previous form field data filling and approval signature. In an embodiment of the present invention, the form data is modified by adding a special approval signature (also called a modification signature) to the electronic file, and a form modification parameter is added to the traditional signature parameter dictionary; the form modification parameter may include one or more groups of names of form fields to be modified and their new values; the final signature appearance interface includes one or more groups of names of form fields to be modified and their new values, the name of the modifier or the impression image, the reason for the modification, and the modification time.

[0032] In the form data modification process of this embodiment, for example, the electronic file processing program can be called first to generate a form signature modification interface and obtain the form signature modification parameters. During the operation, the modifier can use the mouse to select the modified form field, and the form signature modification interface will pop up on the layout of the electronic file. The form signature modification interface is an interactive interface that includes a dialog box, which is used to receive form field modification data and signature-related parameters for the selected form field. The modifier can enter the new value of the form field in this form signature modification interface, fill in the reason for the modification, select the user digital certificate, obtain the name of the modifier or the impression image, and enter the user certificate password to stamp the digital signature. Generally, the name of the modifier is read from the user digital certificate; the impression image of the modifier can be read from the digital certificate, or it can be read from UKEY or the impression server.

[0033] The form data modification in the signature modification parameters can be one or more groups of form fields and the corresponding new values ​​of the form fields.

[0034] In an embodiment of the present invention, after an electronic file has been approved by a certain number of signatures during the business process, a series of form fields in the electronic file will be locked by the signature field. At this time, the form data can be modified multiple times by stamping the digital signature with the signature modification parameters received through the form signature modification interface.

[0035] After the signature modification parameters are obtained, the digital signature is stamped. The digital signature stamping process is divided into three steps: the first step: generating the digital signature appearance according to the signature modification parameters; the second step: writing the signature modification parameters into the signature dictionary of the digital signature; the third step: using existing technology to calculate and write the digital signature value.

[0036] Step 1: Generate digital signature appearance according to signature modification parameters.

[0037] The signature appearance added to the layout of the electronic document can describe the content and method of modifying the form data. One modification method is to modify the value of a certain form field in a directional manner. The corresponding directional signature appearance has a directional mark pointing to the modified form field, and indicates the modification parameters such as the new value of the form field, the name or stamp image of the modifier, the modification time and the reason for modification. A form field can be modified once or multiple times in this way, and the final value of the form field can adopt the value indicated by the digital signature of the last modification. Another modification method for form data is to modify the value of a certain form field in a non-directional manner. The corresponding non-directional signature appearance does not contain a mark pointing to the modified form field, but indicates the name of the modified and added form field, the new value of the form field, the name or stamp image of the signer or modifier, the signature time or modification time, and the modification reason or signature opinion corresponding to the modified form field. Finally, a form field with a value can be added to the form. For example, if the specified form field indicated as modified in the signature appearance does not exist on the original form of the electronic file, the form will expand the specified form field and the value corresponding to the specified form field. If the specified form field already exists on the original form, the value of the specified form field is modified.

[0038] In the above two modification methods, the modification parameters are used as the modification signature elements, and the block diagram is as follows: Figure 2 As shown. The "modified field" and "modified field new value" can be one or more. In the directional modification mode, the "modified field" can indicate the specified form field to be modified through a pointing mark. In the non-directional modification mode, the "modified field" indicates the name of the specified form field to be modified or the name of the newly added form field.

[0039] In the non-directional modification mode, you can modify any one or more form fields in the electronic file by not selecting the specified form field, but marking the form field that needs to be modified in the signature appearance; or marking the new form field that needs to be added in the signature appearance. The forms in the layout file have fixed form filling fields. After the form is authenticated, the form filling field cannot be added, and adding will invalidate the authentication signature. The form field represents the field structure of the form, and the form fields in the form have unique names. When you need to add a form field field to the form, use a digital signature to add the form field and its modified value, which is equivalent to adding a field corresponding to the form field in the form and adopting the modified new value.

[0040] Step 2: Write the signature modification parameters into the signature dictionary of the digital signature

[0041] All signature parameters are usually written into the signature dictionary in the form of a dictionary. General signature parameters include: the name of the signer, signing time, signing comments, signing method, signing host, the signer's public key digital certificate, the signer's stamp, etc. Form field modification information can also be written into the signature dictionary. The form field modification information written into the signature dictionary usually includes: one or more groups of modified form field names and new form field values, the name of the modifier, the reason for modification, the modification time, and the form field pointer. In the signature dictionary, the name of the signer is used as the name of the modifier, the form field modification time can be used as the signing time, and the form field data modification reason can be saved as the signature comment.

[0042] When the form data of the layout file is finally extracted, the final value of the form field will adopt the modified value indicated by the digital signature of the last modification. You can also view all the historical signature versions of the file revision on the final layout file.

[0043] The signature appearance is solidified as the appearance of the digital signature; the modification information is also protected by the digital signature like the basic signature information such as the signer's public key certificate and signature method. The signature appearance is used to be displayed on the layout of the electronic document to indicate the modified form data. The signature appearance can usually be located in a blank space on the layout of the electronic document without obstructing the form fields and form data. Each signature usually corresponds to only one signature appearance. In the prior art, the signature appearance usually only includes the name of the signer, the signing time, etc. Compared with the traditional technology, the signature appearance in the embodiment of the present invention adds the modification information of the form field (including but not limited to the form field name, the new value of the form field, the directional arrow, etc.); the signature dictionary in the embodiment of the present invention adds the form modification parameters (including but not limited to one or more groups of form fields and the new values ​​of the form fields).

[0044] Step 3: Use existing technology to calculate and write digital signature values

[0045] According to the public and private key digital certificates and signature methods in the signature modification parameters, the signature value is calculated and written into the signature dictionary to complete the digital signature stamping.

[0046] The signature method refers to a method or way of digital signature, which includes the following parameters: Signature Handler, such as adbe.pkcs7.detached specifies the signature value format as PKCS#7; signature digest algorithm parameters, such as (SHA1 / SHA256 / SHA385 / SHA512); signature algorithm parameters (RSA / DSA), etc. The general signature method will specify the digest calculation algorithm, signature value calculation algorithm and signature value storage format. The digest calculation algorithms include SHA1 / SHA256 / SHA384 / SHA512, the signature value calculation algorithms include RSA / DSA, etc., and the signature value storage formats include PKCS#7, PKCS#1, or the original mathematical signature value. Using the signature method (such as using adbe.pkcs7.detached signature processor (SignatureHandler), using the SHA256 digest calculation algorithm, and using the RSA signature value calculation algorithm), perform a digest operation on the data within the byte range of the calibrated signature, obtain the digest value from the digest operation result, and then use the user's private key certificate to perform a signature calculation on the above digest value to obtain the signature mathematical value of the digest value. Since the signature mathematical value is not conducive to exchange and storage, the public key certificate, the digest algorithm, and the signature mathematical value are finally encapsulated in a PKCS#7 envelope message, and the final PKCS#7 message is used as the signature value of the electronic file (see ISO32000).

[0047] The process of adding a digital signature to an electronic document may also include the following steps:

[0048] (1) A location for storing the signature value is reserved in the electronic file. The signature value is usually stored in the signature dictionary; at the same time, the byte range of the signature is calibrated. The byte range of the signature refers to the byte range used for signature summary calculation when implementing the digital signature. File data outside this range is not calculated, and the byte data within this range participates in the summary calculation. Usually, the byte range of the signature is the entire electronic file range except for the reserved signature value storage location. In an electronic file, only the storage of the signature value is not protected by the digital signature. Other electronic file data is protected by the digital signature. The significance of the signature value itself lies in the subsequent signature verification.

[0049] (2) Calculate the digest value of the byte range of the electronic document signature according to the signature method. Perform a digest calculation on the electronic document data within the byte range of the electronic document signature. The digest algorithm may be SHA1 / SHA256 / SHA385 / SHA512, etc. (the digest algorithm is ultimately written into the signature dictionary or stored in the envelope message), and obtain the digest value from the calculation result.

[0050] (3) The private key digital certificate of the modifier is used to calculate the signature value of the digest value calculated in step (2). The private key digital certificate of the modifier is used to perform a signature operation on the above digest value. The signature mathematical algorithm adopts RSA or DSA, etc., and finally obtains the signature mathematical value. The signature value format is encapsulated according to the signature value storage format specified in the signature method, such as PKCS#7 envelope message, to obtain the final signature value.

[0051] (4) Write the final signature value into the reserved signature value position in the electronic file.

[0052] In the method embodiment of the present invention, the form data modification process of the electronic file is a digital signature generation process, which uses the signature appearance to receive the form modification parameters and writes the form modification parameters into the signature dictionary. According to the method of the embodiment of the present invention, the form data modification is realized by means of approval signature to solve the problem of modifying the protection field and updating the form field of the old and new versions in the business handling in the actual business scenario. The method does not need to re-perform the business process of the electronic file, and can record all the historical revision traces of the electronic file.

[0053] Figure 3 A partial example of a modified layout file in the embodiment is shown, in which the form field "trial drug" (301) in the layout file (300) is modified and adopts a directional signature appearance (302).

[0054] For example, the field of the experimental drug (301) in the layout culture (300) may enter a locked mode for some reason and cannot be modified. In this case, the signature modification parameters for the form field "experimental drug" can be received by generating a form signature modification interface, including the modifier's digital certificate, the modifier's name or impression image, signature appearance parameters and signature method, the form field to be modified and its new value, modification reason, modification time, etc. The old value of the form field "experimental drug" (301) "1x100mg, white oral tablets" will be modified to "1x150mg, black oral tablets" (that is, the modified new dosage and physical properties). The modification reason is "work error, so correction", and the modification time is "2019-01-2418:36".

[0055] Using a portion of the received signature modification parameters, a directional signature appearance (302) can be generated. The directional signature appearance (302) includes a straight line with an arrow on its left side as a directional mark, which points to the position of the data value field of the modified form field "trial drug" (301), indicating that the new value of the form field in the signature appearance (302) "1x150mg, black oral tablets" will replace the old value of the form field "trial drug" (301) "1x100mg, white oral tablets". The signature appearance (302) also indicates the reason for the modification "work error, so correction", the modification time "2019-01-24 18:36" and the stamp image of the modifier's signature. The new value of the form field can be displayed using different color fonts.

[0056] Figure 4 The following is a flowchart of the operation of modifying a form field in an embodiment. For example, Figure 3 The specific operation process of the embodiment may include the following steps: selecting the form field to be modified in the form layout of the electronic document (step 401); adding or popping up a form signature modification interface including a preview effect of the modifier's signature and a dialog interface in the form layout (step 402); the modifier enters the new value of the form field to be modified and the reason for modification and other signature modification parameters in the dialog box, and uses the modifier's digital certificate to digitally sign to solidify the form modification data (step 403).

[0057] Figure 5 A partial example of a modified layout file in the embodiment is shown, in which a non-directional signature appearance (501) is used in the layout file (500), and a newly added form field "medication time" is indicated in the signature appearance (501).

[0058] For example, Figure 5 The shown medication confirmation form (500) requires that medication time must be entered due to the version upgrade of its electronic file. However, the current version of the business form only defines the "medication date" form field, and does not define the "medication time" form field. In this case, the signature modification parameters for the form field "medication time" can be received by generating a form signature modification interface, including the modifier's digital certificate, the modifier's name or impression image, signature appearance parameters and signature method, the form field "medication time" to be added and its form field value, modification reason, modification time, etc. The form field "medication time" is, for example, "08:10". The modification reason is, for example, "the plan has changed and the time needs to be recorded", and the modification time is "2019-01-24 19:49".

[0059] The above-mentioned part of signature modification parameters can be used to generate a non-directional signature appearance (501) on the form page of the electronic document to indicate the newly added form field "medication time", the specific medication time, the reason for modification, the modification time, and the stamp image of the modifier's signature.

[0060] Figure 6 The following is a flowchart showing the operation of adding a new form field in an embodiment. For example, Figure 5 The specific operation process of the embodiment may include the following steps: selecting any position on the business form as the position of the form signature modification interface (step 601); adding or popping up a form signature modification interface including a signature preview effect and a dialog box interface at the selected position (step 602); the modifier enters the name of the newly added form field, the new value of the form field and the reason for the modification in the dialog box of the interface, and uses the modifier's digital certificate to digitally sign to solidify the form modification data (step 603).

[0061] Figure 7 A schematic diagram of program modules of a business processing system used in an embodiment is shown. The business processing system includes: an acquisition module (701) for calling an electronic file processing program and using a form signature modification interface to acquire signature modification parameters, including form field modification data and signature related parameters; a writing module (702) for writing the acquired signature modification parameters into a signature dictionary, generating a signature appearance including the name of the modified form field and its modified new value, the name or stamp image of the modifier, the modification reason and modification time, and writing the signature appearance into an electronic file as the appearance of a final digital signature; using the modifier's digital certificate to stamp a digital signature on the electronic file; an extraction module (703) for extracting the final form data (i.e., the latest form data) of each form field of the electronic file when reading the electronic file, and the final value of the modified form field will adopt the modified value indicated by the signature of the last modification.

[0062] The above embodiments are exemplary rather than restrictive. Based on the enlightenment of the above embodiments, those skilled in the art can make various modifications or adjustments to the above embodiments without departing from the scope of the principles of the present invention.

Claims

1. A method for modifying form data on a layout electronic file, wherein: The electronic file includes a form field and a form signature field, and the method includes: Generating a form signature modification interface for the electronic file on the layout of the electronic file; wherein the form signature modification interface is used to expand the form field of the electronic file or modify the specified form field of the electronic file, and includes an interactive interface for inputting signature modification parameters; Receiving signature modification parameters through the form signature modification interface without directly modifying the data in the form fields, wherein the signature modification parameters include the modifier's digital certificate, the modifier's name or impression image, digital signature appearance parameters and signing method, form fields to be modified and their new values, modification reasons, and modification time; Write the public key digital certificate, signature opinion, signature time and signature method of the modifier, as well as all modified form fields and their modified new values ​​into the digital signature dictionary of the electronic file; wherein the modification time is used as the signature time, and the modification reason is used as the signature opinion; Generate a signature appearance for presentation on the electronic document using the received signature modification parameters; wherein the signature appearance indicates the name of the modified form field and its modified new value, the name or stamp image of the modifier, the reason for the modification and the modification time; and The electronic document is digitally signed using the received signature modification parameters.

2. The method according to claim 1, wherein Generating a form signature modification interface for the electronic file includes: Select the form field to be modified; Add a form signature modification interface on the layout of the electronic document, The signature appearance further includes a pointing mark pointing to the modified form field in the electronic file.

3. The method according to claim 1 or 2 further comprises, not selecting a specified form field, but instead indicating the names of multiple modified form fields and their modified new values ​​in the signature appearance.

4. The method according to claim 1, further comprising: When it is determined that the electronic file does not include the form field that needs to be modified, the form field including the modified new value is added to the electronic file.

5. The method according to claim 1, wherein: The form fields in the electronic file are allowed to be modified multiple times, wherein the method further comprises: extracting the modified new value of the form field modified last time as the final form data of the modified form field.

6. A device for modifying form data on a layout electronic document, wherein: The electronic file includes a form field and a form signature field, and the device includes: A form signature modification interface generation module, used to generate a form signature modification interface for the electronic file on the layout of the electronic file; wherein the form signature modification interface is used to expand the form field of the electronic file or modify the specified form field of the electronic file, and includes an interactive interface for inputting signature modification parameters; A signature modification parameter receiving module is used to receive signature modification parameters through the form signature modification interface without directly modifying the data in the form fields, wherein the signature modification parameters include the digital certificate of the modifier, the name or impression image of the modifier, digital signature appearance parameters and signing method, form fields to be modified and their new values, modification reasons, and modification time; A writing module, used to write the public key digital certificate, signature opinion, signing time and signing method of the modifier, as well as all modified form fields and their modified new values ​​into the digital signature dictionary of the electronic document; wherein the modification time is used as the signature time, and the modification reason is used as the signature opinion; and to generate a signature appearance for presentation on the electronic document using the received signature modification parameters; wherein the signature appearance indicates the name of the modified form field and its modified new value, the name or stamp image of the modifier, the modification reason and the modification time; and The digital signature stamping module is used to stamp the electronic file with a digital signature using the received signature modification parameters.

7. A device comprising: a memory for storing instructions; as well as A processor coupled to the memory, the instructions, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having stored thereon instructions, which, when executed by a processor of a computer, cause the processor to perform the method according to any one of claims 1 to 5.

Images