A video conference network perception evaluation method, system, electronic device and medium

Abstract

The present invention discloses a method, system, electronic device and medium for evaluating network perception of a video conference. The method includes: slicing the UDP session stream of the video conference; calculating the time interval for receiving a payload data packet and the average size of the payload data packet in each slice; judging the type of the video conference based on the time interval for receiving a payload data packet and the average size of the payload data packet in the slice; calculating the slicing rate for different conference types, judging and marking the high / low quality of each slice based on the calculation result of the slicing rate; calculating the ratio of high / low quality slices, and evaluating the network perception of the video conference. According to the method provided by the embodiment of the present invention, a simple and single indicator is used throughout the entire video conference to evaluate the network perception of the user during the video conference.

Description

Technical Field

[0001] The present application relates to the technical field of video conference quality evaluation, and in particular to a video conference network perception evaluation method. Background Art

[0002] With the rapid development of mobile communication technology, network speed has been improved and network latency has been reduced. Mobile communication services provide a strong foundation for the realization of remote office such as cloud office and remote conferencing. Corresponding mobile remote conferencing has emerged. Through remote conferencing software, people can discuss through video conferencing anytime and anywhere, which has changed the way people work and improved work efficiency. There are many user perception indicators in the remote conferencing software carried on the mobile communication network. Among them, network status perception is an important perception information in the user's use process. Timely discovery of the pros and cons of network status provides an important basis for subsequent improvement of user perception experience.

[0003] Current video conferencing software mainly transmits data packets through UDP (User Datagram Protocol). During a video conference, there are multiple conference status scenarios, such as pure audio, pure video, audio and video mixed, changes in the number of users and shared desktop, as well as changes in one or more combinations of the above scenarios. In order to ensure good user perception in each scenario, the requirements for rate or latency are different. Existing technologies cannot use a simple single indicator throughout the entire video conference to evaluate the user's network perception during the video conference. Summary of the invention

[0004] In view of one or more of the above problems, an embodiment of the present invention provides a method for evaluating network perception of a video conference, so as to solve the problem that it is currently impossible to evaluate the network perception of users during a conference by using simple and effective indicators.

[0005] In order to solve the above technical problems, an embodiment of the present application provides a video conference network perception evaluation method, including:

[0006] Slice the UDP session stream of the video conference;

[0007] Calculating the time interval for receiving the payload data packets and the average size of the payload data packets in each slice;

[0008] Determining the type of the video conference based on the time interval for receiving the payload data packets in the slice and the average size of the payload data packets;

[0009] Calculate the slice rates of different conference types, and judge and mark the quality of each slice according to the calculation results of the slice rates;

[0010] The ratio of the high-quality / poor-quality slices is calculated to evaluate the network perception of the video conference.

[0011] Preferably, slicing the UDP session stream of the video conference includes: slicing the UDP session stream of the video conference according to a duration of 1 second.

[0012] Preferably, judging the state type of the video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets includes:

[0013] If the time interval between the payload data packets in the received slices is greater than 500ms, the video conference is determined to be in a paused state;

[0014] If the time interval between the payload data packets in the received slices is >40ms and <500ms, it is determined that the video conference is in a shared static desktop state;

[0015] If the time interval of the payload data packets in the received slices is >15ms and <40ms, and the length of the payload data packets is >400bytes, it is determined that the video conference is in a shared static video state;

[0016] If the time interval of the payload data packets in the received slice is >15ms and <40ms, and the length of the payload data packets is ≤400byte, the video conference is determined to be in the audio conference state;

[0017] If the time interval of the payload data packets in the received slice is less than 15 ms, and the length of the payload data packets is greater than 400 bytes, it is determined that the video conference is in the audio state of a shared desktop;

[0018] If the time interval between the payload data packets in the received slices is <15 ms, and the length of the payload data packets is ≤400 bytes, it is determined that the video conference is in a shared dynamic video or dynamic desktop state.

[0019] Preferably, the slice rates of different conference types are calculated, and the quality of each slice is determined, including:

[0020] When the video conference is in a paused state, marking the slice as a high-quality slice;

[0021] When the video conference is in a shared static desktop state, the slice is marked as a high-quality slice;

[0022] When the video conference is in a shared static video state, if the average rate of the slice is >250 Kbps, the slice is marked as a high-quality slice; if the average rate is ≤250 Kbps, the slice is marked as a poor-quality slice;

[0023] When the video conference is in an audio conference state, if the average rate of the slice is greater than 70 Kbps, the slice is marked as a high-quality slice; if the average rate is less than or equal to 70 Kbps, the slice is marked as a poor-quality slice;

[0024] When the video conference is in the audio state of sharing the desktop, if the average rate of the slice is greater than 120 Kbps, the slice is marked as a high-quality slice; if the average rate of the slice is less than or equal to 120 Kbps, the slice is marked as a poor-quality slice;

[0025] When the video conference is in the state of sharing dynamic video or dynamic desktop, if the average rate of the slice is >500Kbps, the slice is marked as a high-quality slice; if the average rate of the slice is ≤500Kbps, the slice is marked as a poor-quality slice.

[0026] Preferably, calculating the ratio of the high-quality / poor-quality slices and performing network perception evaluation includes:

[0027] The poor quality slice ratio is the number of poor quality slices / total slice data*100%, and the poor quality slice ratio is used as the video conference freeze ratio.

[0028] An online video conference network perception evaluation system, characterized in that the system comprises:

[0029] The session stream processing module is used to slice the UDP session stream of the online video conference;

[0030] A slice data calculation module, used to calculate the time interval for receiving a payload data packet and the average size of the payload data packet in each slice;

[0031] A conference type determination module, used to determine the type of online video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets;

[0032] A slice quality judgment module is used to calculate the slice rate of different conference types, and judge and mark the quality of each slice according to the calculation result of the slice rate;

[0033] The network perception evaluation module is used to calculate the ratio of the high-quality / poor-quality slices and evaluate the network perception of the online video conference.

[0034] Preferably, the network perception evaluation module is further used to use the value of the number of poor quality slices / total slice data*100% as the jamming ratio of the online video conference, and to determine whether jamming occurs in the online video conference.

[0035] An electronic device for video conferencing network perception assessment includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned video conferencing network perception assessment method when executing the program.

[0036] A computer-readable storage medium includes instructions, which, when executed on a computer, enable the computer to execute the above method.

[0037] The technical solution of the present application can identify changes in one or more scene combinations such as pure audio, pure video, audio and video mixture, changes in the number of users and shared desktop during a video conference through the characteristics of UDP session stream slicing, and then use corresponding indicator thresholds to judge the user's perception according to the current different scenes of the video conference.

[0038] This application uses a single indicator to evaluate user perception during the entire conference process. It can be used to evaluate video conferencing business perception in multiple dimensions such as users or networks, and to monitor indicators during single (multi-) user video conferences in real time. It can also be used for statistical analysis of single (multi-) user video conferences and to guide the implementation of related network optimization solutions to ensure that users have good perception during real-time meetings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention can be better understood from the following description of specific embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0040] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features.

[0041] Figure 1 A flow chart of a video conferencing network perception evaluation method provided in an embodiment of the present application;

[0042] Figure 2 An example diagram of identifying different conference scenarios in a video conference network perception evaluation method provided in an embodiment of the present application;

[0043] Figure 3 An algorithm judgment flow chart is provided in a video conferencing network perception evaluation method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific configuration and algorithm proposed below, but covers any modification, replacement and improvement of elements, parts and algorithms without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity to the present invention.

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of example embodiments to those skilled in the art. In the drawings, the thickness of regions and layers may be exaggerated for clarity. The same reference numerals in the drawings represent the same or similar structures, and thus their detailed description will be omitted.

[0046] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solution of the present invention may be practiced without one or more of the specific details, or other methods, components, materials, etc. may be adopted. In other cases, known structures, materials or operations are not shown or described in detail to avoid blurring the main technical creativity of the present invention.

[0047] Currently, video conferencing software supports multiple terminals and multiple modes of joining the meeting. It not only conforms to people's usage habits in the mobile Internet era, but also has richer and more intelligent functions, such as desktop sharing, file sharing, live conferences, video recording, raising hands to speak and other interactive functions. In daily office work, employees can quickly organize, initiate and participate in meetings through their own conference accounts, greatly improving the efficiency of internal collaboration and communication within the enterprise.

[0048] UDP does not need to establish a connection between the client and the server before transmitting data, and has no timeout retransmission mechanism, so the transmission speed is very fast; current video conferencing software mainly transmits data packets through the UDP protocol.

[0049] Please refer to Figure 1 , Figure 1 A flow chart of a video conferencing network perception evaluation method provided in an embodiment of the present application. Among them:

[0050] Step S1: Slice the UDP session stream of the video conference;

[0051] The session stream could be UDP data from a fetch server and then slicing that data.

[0052] Step S2: Calculate the time interval for receiving the payload data packets and the average size of the payload data packets in each slice;

[0053] Step S3: determining the type of video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets;

[0054] Step S4: Calculate the slice rates of different conference types, and judge and mark the quality of each slice according to the calculation results of the slice rates;

[0055] Step S5: Calculate the ratio of the high-quality / low-quality slices to evaluate the network perception of the video conference.

[0056] In the above embodiment, since there are multiple conference status scenarios in the video conference, the code stream (session stream) transmission rates of different scenarios are different. For example, there may be only audio, video, desktop whiteboard sharing, or a combination of the above multiple scenarios, and the transmission rate is used as a basis for judging whether the video is stuck in the online conference usage perception. Therefore, this embodiment first slices the UDP session stream, and then calculates the time interval of the payload data packet (payload packet) in each slice, judges the conference status scenario according to the time interval, calculates the rate of slices in different conference states, judges whether each slice is a high-quality / poor-quality session stream, and calculates the proportion of poor-quality session streams as a video conference stuck indicator for judging user usage perception.

[0057] In the above embodiments, in order to ensure good user perception in each scenario, the requirements for network rate or latency are different. UDP session stream slicing is used to evaluate user perception (stuttering) during the meeting. Simple indicators are used throughout the entire video conference to evaluate the user's network perception during the video conference, which effectively provides an important basis for subsequently ensuring good user network perception.

[0058] In another embodiment of the present application, slicing the UDP session stream of the video conference includes: slicing the UDP session stream of the video conference according to a duration of 1 second.

[0059] The network resources are flexibly allocated according to the duration of 1 second, and the network is formed on demand. For example, the UDP session stream in a video conference is sliced ​​according to the duration of 1 second as the basic data source for calculation, and the following characteristics are obtained:

[0060] The first packet data size of the session stream: 355 or 356 bytes;

[0061] Characteristics of positions 109 to 116: c0 9f c0 5d c0 61c0 57.

[0062] Of course, slicing according to a duration of 1s in the above embodiment is a preferred implementation method in this application. In practical applications, an appropriate slicing duration can be selected as the basic data source according to actual conditions, and this application does not limit this.

[0063] Please refer to Figure 2 and Figure 3 , Figure 2 An example diagram of identifying different conference scenarios in a video conference network perception evaluation method provided in an embodiment of the present application; Figure 3 In another video conference network perception evaluation method provided in the embodiment of the present application, the algorithm judgment flow chart. In another embodiment of the present application, the state type of the video conference is judged according to the time interval for receiving the payload data packet in the above 1s time slice (Bits / 1s) and the average size of the payload data packet, the slice rate of the above different conference types is calculated, and the quality of each slice is judged. Figure 2 It can be concluded that when slicing with a duration of 1s is used as the data source:

[0064] If the time interval of the payload data packets (Payload packets) in the received slice is >500ms, the corresponding video conference status is paused; for example, when entering the meeting, the video is turned off, the audio is muted, and the desktop whiteboard is not shared; at this time, the slice can be directly marked as a high-quality slice.

[0065] If the time interval of the payload data packets in the received slice is >40ms and <500ms, the corresponding video conference status is the shared static desktop status; for example, during the meeting, the video is turned off, the audio is muted, and only the static desktop whiteboard is shared, which is similar to the paused state of the meeting above where only the static desktop whiteboard is shared (for example, only one page of PPT is shared without turning pages); at this time, the slice can be directly marked as a high-quality slice.

[0066] If the time interval of the payload data packets in the received slices is >15ms and <40ms, and the length of the payload data packets is >400byte, the corresponding video conference is in a shared static video state, for example, the video is shared, but the audio is muted (i.e., only one person's head portrait video is displayed in the conference). If the average rate of the slice is >250Kbps, it is marked as a high-quality slice, otherwise it is marked as a poor-quality slice.

[0067] If the time interval of the payload data packets in the received slice is >15ms and <40ms, and the length of the payload data packets is ≤400bytes, the corresponding video conference state is the audio conference state; for example, the video is not turned on, only the voice conference is turned on. If the average rate of the slice is >70Kbps, it is marked as a high-quality slice, otherwise it is marked as a poor-quality slice.

[0068] If the time interval of the payload data packets in the received slice is <15ms, and the length of the payload data packet is >400byte, the corresponding video conference status is the audio status of the shared desktop, for example, only the audio is turned on in the meeting, and the desktop content is shared; among them, if the average rate of the slice is >120Kbps, it is marked as a high-quality slice, otherwise it is marked as a poor-quality slice.

[0069] If the time interval of the payload data packets in the received slice is <15ms, and the length of the payload data packets is ≤400byte, the corresponding video conference state is shared dynamic video or dynamic desktop state. If the average rate of the slice is >500Kbps, it is marked as a high-quality slice, otherwise it is marked as a poor-quality slice.

[0070] The above embodiment is based on 1s time slice (Bits / 1s) as the basic data source, which is the preferred implementation scheme in this application. The slice duration can be selected as the data source according to the actual situation. This application does not make specific restrictions on this, but the corresponding scheme should also fall within the scope of protection of this application.

[0071] Among the many user perception indicators of video conferencing, network status perception is an important perception information in the user's use process. Timely discovery of the pros and cons of network status can provide an important basis for subsequent improvement of user perception experience. At the same time, the video conference freeze ratio is also an important perception item in video conferencing. In one embodiment of the present application, the proportion of poor-quality slices is used as the video conference freeze ratio to perform network perception evaluation. Of course, the proportion of high-quality slices can also be used as a basis for good network evaluation. Among them:

[0072] The ratio of poor quality slices is the number of poor quality slices / total slice data*100%.

[0073] To sum up, in the above-mentioned embodiments of the technical solution of the present application, based on bitstream decoding (session stream), according to the bitstream characteristics of the video conference, a (based on) UDP bitstream segmentation evaluation method is proposed. It only needs to collect the UDP bitstream, identify the conference scene, and calculate the size and slice rate of the payload data packet in the corresponding scene, so as to realize the perception evaluation (including the percentage of lag, etc.) in the video conference, which solves the shortcoming of the prior art that it is impossible to evaluate the user network perception of the entire conference process through a single indicator. The solution is simple and effective.

[0074] However, it should be clear that the present invention is not limited to the specific configurations and processes described above and shown in the figures. Moreover, for the sake of simplicity, a detailed description of known methods and techniques is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0075] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0076] The present invention can be implemented in other specific forms without departing from its spirit and essential features. For example, the algorithms described in the specific embodiments can be modified, and the system architecture does not depart from the basic spirit of the present invention. Therefore, the current embodiments are regarded as exemplary and non-restrictive in all aspects, and the scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning and equivalent scope of the claims are thus included in the scope of the present invention.

[0077] The present application also provides an online video conference network perception evaluation system, including:

[0078] The session stream processing module is used to slice the UDP session stream of the online video conference;

[0079] A slice data calculation module, used to calculate the time interval for receiving a payload data packet and the average size of the payload data packet in each slice;

[0080] A conference type determination module, used to determine the type of online video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets;

[0081] A slice quality judgment module is used to calculate the slice rate of different conference types, and judge and mark the quality of each slice according to the calculation result of the slice rate;

[0082] The network perception evaluation module is used to calculate the ratio of the high-quality / poor-quality slices and evaluate the network perception of the online video conference.

[0083] Preferably, the network perception evaluation module is further used to use the value of the number of poor quality slices / total slice data*100% as the jamming ratio of the online video conference, and to determine whether jamming occurs in the online video conference.

[0084] An embodiment of the present application also provides an electronic device for video conferencing network perception evaluation, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the video conferencing network perception evaluation method as described above when executing the program.

[0085] The embodiment of the present application also provides a computer-readable storage medium, including instructions, which, when executed on a computer, enable the computer to execute the method as described above.

[0086] The specific implementation methods of the above-mentioned electronic system, device and computer-readable storage medium are the same as those of the method embodiment and will not be repeated here.

[0087] Those skilled in the art should understand that the above embodiments are exemplary rather than restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on the study of the drawings, the specification and the claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other devices or steps; the indefinite article "a" does not exclude a plurality; the terms "first" and "second" are used to indicate names rather than to indicate any specific order. Any figure marks in the claims should not be understood as limiting the scope of protection. The functions of multiple parts appearing in the claims can be implemented by a single hardware or software module. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A video conferencing network perception evaluation method, characterized in that: include: Slice the UDP session stream of the video conference; Calculating the time interval for receiving the payload data packets and the average size of the payload data packets in each slice; Determining the type of the video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets, wherein the type of the video conference includes at least one of a pause state, a shared static desktop state, a shared static video state, an audio conference state, a shared desktop audio state, a shared dynamic video state, and a shared dynamic desktop state; Calculate the slice rates of different conference types, and judge and mark the quality of each slice according to the calculation result of the slice rate, the type of the video conference, and the corresponding indicator threshold; The ratio of the high-quality / poor-quality slices is calculated to evaluate the network perception of the video conference.

2. The video conferencing network perception evaluation method according to claim 1 is characterized in that: Slicing the UDP session stream of a video conference includes: The UDP session stream of the video conference is sliced ​​into 1-second segments.

3. The video conferencing network perception evaluation method according to claim 2 is characterized in that: Determining the state type of the video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets includes: If the time interval between the payload data packets in the received slice is greater than 500 ms, the video conference is determined to be in a paused state; If the time interval between the payload data packets in the received slices is >40ms and <500ms, it is determined that the video conference is in a shared static desktop state; If the time interval of the payload data packets in the received slices is >15ms and <40ms, and the length of the payload data packets is >400bytes, it is determined that the video conference is in a shared static video state; If the time interval of the payload data packets in the received slice is >15ms and <40ms, and the length of the payload data packets is ≤400byte, the video conference is determined to be in the audio conference state; If the time interval of the payload data packets in the received slice is less than 15 ms, and the length of the payload data packets is greater than 400 bytes, it is determined that the video conference is in the audio state of a shared desktop; If the time interval between the payload data packets in the received slices is <15 ms, and the length of the payload data packets is ≤400 bytes, it is determined that the video conference is in a shared dynamic video or dynamic desktop state.

4. The video conference network perception evaluation method according to any one of claims 1 to 3, characterized in that: Calculate the slice rate for different conference types and judge the quality of each slice, including: When the video conference is in a paused state, marking the slice as a high-quality slice; When the video conference is in a shared static desktop state, the slice is marked as a high-quality slice; When the video conference is in a shared static video state, if the average rate of the slice is >250 Kbps, the slice is marked as a high-quality slice; if the average rate is ≤250 Kbps, the slice is marked as a poor-quality slice; When the video conference is in an audio conference state, if the average rate of the slice is greater than 70 Kbps, the slice is marked as a high-quality slice; if the average rate is less than or equal to 70 Kbps, the slice is marked as a poor-quality slice; When the video conference is in the audio state of sharing the desktop, if the average rate of the slice is greater than 120 Kbps, the slice is marked as a high-quality slice; if the average rate of the slice is less than or equal to 120 Kbps, the slice is marked as a poor-quality slice; When the video conference is in the state of sharing dynamic video or dynamic desktop, if the average rate of the slice is >500Kbps, the slice is marked as a high-quality slice; if the average rate of the slice is ≤500Kbps, the slice is marked as a poor-quality slice.

5. The video conferencing network perception evaluation method according to claim 1 is characterized in that: Calculating the ratio of the high-quality / poor-quality slices and performing network perception evaluation includes: The poor quality slice ratio is the number of poor quality slices / total slice data*100%, and the poor quality slice ratio is used as the video conference freeze ratio.

6. A video conferencing network perception evaluation system, characterized in that: The system comprises: The session stream processing module is used to slice the UDP session stream of the video conference; A slice data calculation module, used to calculate the time interval for receiving a payload data packet and the average size of the payload data packet in each slice; a conference type determination module, configured to determine the type of the video conference according to the time interval for receiving the payload data packets in the slice and the average size of the payload data packets, wherein the type of the video conference includes at least one of a pause state, a shared static desktop state, a shared static video state, an audio conference state, a shared desktop audio state, a shared dynamic video state, and a shared dynamic desktop state; A slice quality judgment module is used to calculate the slice rate of different conference types, and judge and mark the quality of each slice according to the calculation result of the slice rate, the type of the video conference, and the corresponding indicator threshold; The network perception evaluation module is used to calculate the ratio of the high-quality / poor-quality slices and evaluate the network perception of the video conference.

7. The video conference network perception evaluation system according to claim 6, characterized in that: include: The network perception evaluation module is also used to use the value of the number of poor quality slices / total slice data*100% as the jamming ratio of the video conference, and to determine whether the video conference has jammed.

8. An electronic device for video conferencing network perception assessment, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the video conferencing network perception evaluation method as described in any one of claims 1 to 5 are implemented.

9. A computer-readable storage medium comprising instructions, which, when executed on a computer, enables the computer to execute the steps of the method according to any one of claims 1 to 5.

Images