Patent Application
20150331891
The present invention relates to a method and an apparatus for sequencing metadata events, specifically, in a temporal order.
In production industry, for example the movie production industry, data events are often arranged on a timeline according to their capture information for subsequent display or review purpose. The arrangement of data events like recorded video or audio files in a temporal sequence is generally easy, since there are standardized container formats being assigned to the files and providing escorting information such as start- and stop time-code, duration time or frame count numbers.
However, a proper temporal arrangement of data events like metadata is more complicated and tricky. This is due to the variety of partly non-standardized temporal register schemes assigned to different metadata items. If metadata is captured in computer files, one or more of the following well-known temporal register schemes might be arbitrarily used:
When the metadata events include video data, the temporal schemes, such as the frame number references, the actual time-codes, and the actual wall-clock time, can also be burned into the video data. If the metadata events are streamed rather than captured as files, the above register schemes, except those associated with file creation time, can be applied.
The temporal accuracies of the above mentioned and other register schemes are various and different. In general, the resolution and precision of those associated to a time-code are higher than those associated to a wall-clock time.
When several temporal schemes are applied to metadata events to be sequenced, there is one problem of the choice of specific schemes based on which the metadata events are sequenced. The sequence result of the metadata events would not be the same when different register scheme is used. In other words, the sequence result can be unreliable and non-repeatable.
Therefore, it is an objective of the present invention to propose an improved solution for temporally sequencing metadata events. More specifically, the present invention provides a method and an apparatus for sequencing metadata events according to a priority order of the temporal schemes thereof.
According to the invention, a method for sequencing metadata events comprises:
Accordingly, an apparatus configured to sequence metadata events comprises:
Also, a computer readable storage medium having stored therein instructions for sequencing metadata events, which when executed by a computer, cause the computer to:
For a better understanding the invention shall now be explained in more detail in the following description with reference to the figures. It is understood that the invention is not limited to this disclosed exemplary embodiments and that specified features can also expediently be combined and/or modified without departing from the scope of the present invention as defined in the appended claims. In the figures:
The metadata events denoted in this invention can be any kind of metadata events that are associated to different types of data events. Optionally, the metadata events can be associated to at least one data event of a type selected from the group consisting of image, audio data, video data, machine, and industrial process. For example, the metadata events can be associated to image, video, and audio data events when it comes to the application in the movie production industry or the consumer product industry.
The detection 11 of temporal schemes of the metadata events can be performed respectively on each of the metadata events or on several metadata events at a same time. Of course, any methods or techniques known in the field can be applied to and used for the detection.
Optionally, the method can further comprise assigning 13 temporal schemes to the metadata events, as shown in
One preferred embodiment of the method for sequencing metadata events according to this invention is applied when the metadata events are associated to at least one video data event. That is, the metadata events are used to describe individual information or are a collection of varied information of the video data, by which they can facilitate the understanding, classification, and management of the video data. In this case, the temporal schemes of the metadata events are preferably related to one of a time-code, frame count information, and a wall-clock time. More preferably, the priority order of the temporal schemes is those related to a time-code, followed by those related to frame count information, and at last those related to a wall-clock time. Additionally, if the file creation time of the metadata event is available, the priority thereof should be lower than that related to a wall-clock time.
The wall-clock time, or wall-time, is referred to a measure of the real time from the start to the completion of a task performed by a computer, which is well-known in the field. In this embodiment, it is preferably referred to a local time of the location where the metadata are captured. Optionally, a system time representing a computer system's notion of the passing of time can be used instead. With the widespread availability of computer networks nowadays, it is preferable that the system time is correlated to the wall-clock time, and thus it covers the UTC when the metadata are captured from different locations of the world with different time zones.
In particular, the metadata events are preferably checked and sequenced according to the following priority order of the temporal schemes thereof:
The metadata events to be sequenced are first checked and detected 11 to see which of the above temporal schemes are associated thereto. If the temporal schemes are insufficient or if there is a need for additional temporal schemes, it is possible to manually assign 13 extra temporal schemes to the metadata events, and the assigned temporal context is preferably with a highest priority among others. Subsequent to the manually assigned temporal context, those temporal schemes related to a time-code generally have a higher priority than those related to frame count information. If none of these temporal schemes are available, those related to a wall-clock time or the file creation time can also be used, although they are less precise.
The above preferred priority order of the temporal schemes is derived basically from the experience known in the field. Besides the manual assignment of metadata events in a timeline, reference information burned into the video event is generally considered the most exact temporal scheme, followed by reference information coded within files or streams of the video event (e.g. coded in XML, html, file headers or -footers, or other provisions in file- or streaming formats). There is very limited space for reference information coded within filename of the video event.
In addition, the preferred priority order is also derived from the fact that the resolution and accuracy of temporal schemes related to a time-code are generally the best. Temporal schemes related to frame count information is of similar resolution and accuracy, but sometimes there is no additional information available to link the frame count information to a time-code. Those temporal schemes related to a wall-clock time have a poor resolution compared to the others. The implementation of a wall-clock time in different devices is often poorly synchronized, which results in an unreliable temporal scheme. One optional approach to compensate for the above drawbacks is the placement of wall-clock time within a time-code-based timeline while the frame unit is set as zero, or vice versa.
Certain steps of the above priority order list can be skipped for some specific cases. For example, when an image analysis cannot be operated to detect burn-in time or frame count information of the metadata events, the steps of 1, 2 and 7 can be skipped. When a reference mapping between time-code and frame count information of the metadata events is not available, the steps of 2, 4 and 6 would become impractical and can be skipped.
In other preferred embodiments of the method for sequencing metadata events according to this invention, the metadata events can also be associated to machines or industrial processes. In these cases, the parallel processes or machines are preferably either registered to or controlled with a time-code or a wall-clock system. Besides, these processes or machines preferably generate data events or files when reporting about started and finished process cycles with respect to a time-code or a wall-clock.
One exemplary implementation is for the printing industry where several consecutive wheels transport papers and an observation camera is placed to monitor the wheels. Each wheel controller periodically write log files with a file creation date and/or time-stamps about the status, e.g. speed, of the individual wheel. The time-relevant information is normally derived from an independent system clock running within the wheel controllers. The camera captures images, into each of which synchronized time stamp is generally in-painted. It would be essential for a recorder or central controller to order and correlate all the metadata events from both the individual wheels and the associated camera images. By implementing the method of this invention, the various metadata events can be easily sequenced and managed according to the timestamps thereof and a preferable priority of the temporal schemes.
According to the method of the present invention described above, the sequencing of metadata events can be improved to achieve a higher resolution and accuracy, even when the metadata events are provided with multiple temporal schemes. In addition, the priority order of the temporal schemes can be arbitrarily determined by a user or a device, based on various demands and requirements. While a higher accuracy of the temporal sequencing might generally be the most important expectation, other specific target for the sequencing of the metadata events can also be achieved by the flexible priority order of the temporal schemes.
An apparatus 20 configured to perform the method for sequencing metadata events according to the present invention is schematically depicted in
| Number | Date | Country | Kind |
|---|---|---|---|
| 14305698.4 | May 2014 | EP | regional |
