Patent Publication Number: US-10789987-B2

Title: Accessing a video segment

Description:
RELATED APPLICATION 
     This application was originally filed as Patent Cooperation Treaty Application No. PCT/FI2016/050670 filed Sep. 26, 2016 which claims priority benefit to EP Patent Application No. 15187333.8, filed Sep. 29, 2015 and EP Patent Application 16161457.3, filed Mar. 21, 2016. 
     TECHNOLOGICAL FIELD 
     Embodiments of the present invention relate to accessing a video segment. 
     BACKGROUND 
     When video is recorded it is desirable for a user to be able to access a desired segment of the video. 
     This may, for example, be achieved by fast forwarding or fast rewinding the video. skipping forward or backwards by chapters, or by selecting chapters from a menu. 
     BRIEF SUMMARY 
     According to various, but not necessarily all, embodiments of the invention there is provided a method comprising: causing provision of a visual access menu to enable a user to access video segments of a scene comprising: causing display of at least a portion an image of the scene; causing display, at a first location in the scene, of a first user-selectable menu option that when selected causes access to one or more first video segments of activity at the first location in the scene; and causing display, at a second location in the scene, of a second user-selectable menu option that when selected causes access to one or more second video segments of activity at the second location in the scene. 
     According to various, but not necessarily all, embodiments of the invention there is provided a method comprising: using image processing to parameterize one or more videos; determining spatio-temporal video segments based on parameterization; determining a first video excerpt representing a first video segment and create a first link from a video excerpt to the first video segment; and displaying an access menu of video excerpts for selection by a user, wherein user selection of the first video excerpt in the access menu activates the first link to access the first video segment. 
     According to various, but not necessarily all, embodiments of the invention there is provided examples as claimed in the appended claims. 
    
    
     
       BRIEF DESCRIPTION 
       For a better understanding of various examples that are useful for understanding the brief description, reference will now be made by way of example only to the accompanying drawings in which: 
         FIG. 1  illustrates an example of a method of providing a visual access menu that enables a user to access video segments of a scene; 
         FIG. 2  illustrates an example of a system for capturing video of a scene; 
         FIG. 3  illustrates an example of an image of the scene; 
         FIG. 4  illustrates an example of segmenting a video; 
         FIG. 5  illustrates an example of a method for generating the visual access menu; 
         FIG. 6  illustrates an example video that has been parameterized using position and time; 
         FIGS. 7A and 7B  illustrate different examples of segmenting the video illustrated in  FIG. 6 ; 
         FIG. 8A, 8B, 8C  illustrate different examples of parameterization and segmentation of the video illustrated in  FIG. 6 ; 
         FIG. 9  illustrates an example of an apparatus; and 
         FIG. 10  illustrates an example of a record carrier. 
         FIGS. 11A, 11B, 11C, 11D  illustrate a subject-specific parameterization of the video according to when and where any activity occurs in the video and additionally, at least, who or what is performing the activity; 
         FIGS. 12A and 12B  illustrate an object-specific parameterization of the video according to when and where any activity occurs in the video and additionally, at least, who or what the activity is performed in relation to; 
         FIGS. 13A and 13B  illustrate an example of a visual access menu comprising multiple user-selectable menu options for different waypoints along a route taken by the first subject, before and after selection of one of the waypoint user-selectable menu options; 
     
    
    
     DETAILED DESCRIPTION 
     The figures illustrate a method  100  for providing a visual access menu  110  that enables a user to access video segments  310  of a scene  202 . The method comprises: 
     a) causing display of an image  112  of at least a portion of the scene  202   
     b) causing display, at a first location  122   1  in the scene  202 , of a first user-selectable menu option  120   1  that when selected causes access to one or more first video segments  310  of activity at the first location  122   1  in the scene  202 ; and 
     c) causing display, at a second location  122   2  in the scene  202 , of a second user-selectable menu option  120   2  that when selected causes access to one or more second video segments  310  of activity at the second location  122   2  in the scene  202 . 
       FIG. 1  illustrates an example of the method  100 . The result of the method  100  is a visual access menu  110  that enables a user to access video segments  310  of a scene  202 . 
     The menu  110  comprises an image  112  of the scene  202  and one or more user-selectable menu options  120   n , at different locations  122   n  in the scene  202 , that when selected cause access to one or more respective video segments  310  of activity at the location  122   n  in the scene  202 . 
     The user selectable menu options  120   n  are in this example and in other examples may be user-selectable menu items. A field of view of the scene  202  is typically greater than the field of view of the display used to display the scene and consequentially only a portion of the scene  202  is displayed at any one time without zooming out (reducing resolution). 
     In the illustrated example, but not necessarily all examples, the field of view of the display relative to the field of view of the scene is such that multiple user-selectable menu options  120   n  are displayed simultaneously at different locations  122   n  in the scene  202 . However, if the field of view of the display changes relative to the field of view of the scene or the separation of the locations  122   n  of the multiple user-selectable menu options  120   n  were greater, then only one or none of the multiple user-selectable menu options  120   n  would be displayed. A user may be able to change a size of the field of view of the display relative to the field of view of the scene by zooming in or zooming out. A user may be able to change a relative position of the field of view of the display relative to the field of view of the scene  202  by panning left or right and/or by panning up and down. 
     In this example, but not necessarily all examples, the displayed menu  110  comprises: the image  112  of at least a portion of the scene  202 ; at a first location  122   1  in the scene  202 , a first user-selectable menu option  120   1  that when selected causes access to one or more first video segments  310 ; and at a second location  122   2  in the scene  202 , a second user-selectable menu option  120   2  that when selected causes access to one or more second video segments  310 . 
     The one or more first video segments  310  of activity at the first location  122   1  in the scene  202  are segments of video that record activity at, near or in relation to the first location  122   1  in the scene  202 . For example the one or more first video segments  310  may be segments of video that record activity at the first location  122   1  in the scene  202  and/or record activity near to the first location  122   1  in the scene  202  and/or record activity that starts, ends or temporarily occurs at or near the first location  122   1  The one or more first video segments  310  may be captured by the same or by different video cameras. 
     The one or more second video segments  310  of activity at the second location  122   2  in the scene  202  are segments of video that record activity at, near or in relation to the second location  122   2  in the scene  202 . For example the one or more second video segments  310  may be segments of video that record activity at the second location  122   2  in the scene  202  and/or record activity near to the second location  122   2  in the scene  202  and/or record activity that starts, ends or temporarily occurs at or near the second location  122   2 . The one or more second video segments  310  may be captured by the same or by different video cameras. 
     The one or more first video segments  310  and the one or more second video segments  310  may be captured by the same or by different video cameras. 
       FIG. 2  illustrates an example of a system  200  for capturing video of a scene  202 . The system  200  comprises one or more digital video cameras  206  that capture video of the whole or a part of the scene  202  determined by the field of view  204  of the camera  206 . 
       FIG. 3  illustrates an example of an image  112  of the scene  202  created from a single field of view  204   1  of a single camera or created by combining overlapping fields of view  204   2  of different cameras. In some but not necessarily all examples, a panoramic camera  206  may be used to create a panoramic image  112  that has a very wide field of view. It may have a very large width W to height H aspect ratio, for example, exceeding 4 or 5. 
     The image  112  is defined by values of the image pixels. Each image pixel has a position r within the image  112 . A video of the scene  202  is defined by a temporal sequence of images  112 . The first location  122   1  in the scene  202  may be defined by a first position r 1    302 . The second location  122   2  in the scene  202  may be defined by a second position r 2    302 . 
       FIG. 4  illustrates an example of segmenting a video  300 . The video  300  in this example is represented as a spatio-temporal area—all values of position r  302  are plotted against time. The video  300  may originate from one or more cameras and may comprise multiple video files. A video segment  310  is a spatio-temporal sub-area. The video segment  310  is spatially limited and temporally limited. The video segment, in this example, is limited to a sub-set  320  of the possible values for position r  302  and to an independent sub-set  322  of the possible values for time t  304 . The determination of a video segment  310  comprises determining the sub-set  320  of the values for position r  302  and the sub-set  322  of the values for time t  304 . 
       FIG. 4  illustrates an example of parameterization of the video  300  according to multiple parameters. In this example the parameters are the position r  302  and time t  304 . A video segment  310  is determined based on the parameterization of video  300 , and, in particular the sub-sets  320 ,  322  for the respective possible parameter values. 
     It will be noticed that in this example, the sub-set  320  of the values for position r  302  defines a continuous uninterrupted range of the values for position r  302  (contiguous pixels) and the sub-set  322  of the possible values for time t  304  defines a continuous uninterrupted range of the values for time t  304 . 
     If the position r  302  is defined in terms of orthogonal Cartesian component x, y then a segment may be defined spatially by a range of x, a range of y or a range of both x and y. 
     Other parameterization of the video  300  is possible. 
       FIG. 5  illustrates an example of a method  500  for generating the visual access menu  110 . 
     At block  502 , one or more videos  300  defining the scene  202  are parameterized. The videos  300  may be spatially overlapping or spatially distinct. The videos  300  may be temporally overlapping or temporally distinct. As a combination they record activity in the scene  202  over time. 
     The videos  300  may be calibrated to have a common spatial reference frame so that the spatial relationship of one video to another is known. Alternatively, image processing may be used to create a common spatial reference frame. Image processing may be used to recognise fixed image features in the videos and recognise which videos overlap spatially by matching patterns of the fixed image features between videos. In this way the one or more videos  300  defining the scene  202  can be parameterized using a position r  302  in a common (shared) spatial reference frame. 
     The videos may be calibrated to have a common time reference frame so that the temporal relationship of one video to another is known. Alternatively, image processing may be used to create a common time reference frame. Image processing may be used to recognise changing image features in the videos and recognise which videos overlap temporally (and spatially) by matching patterns of the changing image features between videos. In this way the one or more videos  300  defining the scene  202  are parameterized using a time t  304  in a common (shared) time reference frame. 
     Image processing may be used to create other reference frames for parameterization of the videos  300 . Image processing may be used to recognise an event in the videos  300  by matching patterns of changing image features with a reference for the event. In this way the one or more videos  300  defining the scene  202  are parameterized using the event as a parameter. 
     The occurrence of the event may be logged as occurring at position r and at time tin the videos  300 , causing parameterization of the video  300  according to at least when and where an event occurs in the video  300 . 
     One example of an event may for example be activity in the scene  202 , which means a change in a content of the scene. 
     Another example of an event may for example be recognition of a particular user or object. 
     Another example of an event may for example be recognition of an interaction between two or more persons or objects. 
     Another example of an event may for example be recognition of a particular action or activity. 
     An event may be a combination of events such as (any) activity in the scene  202  by a particular person or in relation to a particular object, causing parameterization of the video according to at least when and where activity occurs in the video and who or what is performing the activity. 
     Another example of an event that is a combination of events, is where the event is a particular activity in the scene  202  by any person or by a particular person or in relation to any object or a particular object, causing parameterization of the video according to at least when and where activity occurs in video and what the activity is. 
     The parameters used for parameterization of the video  300  may a fixed set of parameters or a variable set of parameters. For example, a user may be able to determine one or more or all of the parameters used for parameterization of the video  300 . 
     Additionally or alternatively, the video  300  may be automatically parameterized using putative parameters to determine an optimal set of parameters for parameterization of the video  300 . The optional set of parameters may then be automatically used for parameterization of the video  300  or they may be presented as selectable parameters to a user from which a user may be able to determine one or more or all of the parameters used for parameterization of the video or videos  300 . 
     One method for optimal parameterization of the video  300  is to use k-means clustering. Given a set of events (x 1 , x 2 , . . . , x n ). An event may be defined in a parameter space by a vector having a component value for each parameter. Each event is a vector in the parameter space defined by the multiple parameters, k-means clustering places the n events into k (≤n) sets S={S 1 , S 2 , . . . , S k } so as to minimize the within-cluster sum of squares. It solves: 
     
       
         
           
             
               
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     where μ i  is the mean of members of S i . This finds the optimal clustering for a defined parameter space. A search may be performed over multiple parameter spaces to find the optimal parameter space and the optimal clustering for that parameter space. 
     Parameters may be used to define events in terms of where the event occurs, when the event occurs, and other characteristics of the event or a participant in the event such as, for example, who or what is involved in the event, what activity the event relates to, parameters describing a participant such as speed, distance from ground, relative positions of joints, relative position to other objects etc. 
     At block  504 , the method  500  determines one or more video segments  310  based on the parameterization of the video  300 . 
     For example, events that occur sequentially in time and are clustered according to position and, optionally, one or more other parameters, may be used to define a video segment  310 . These events are inliers within the cluster and may indicate a usual prototypical event for the time period of the video. 
       FIG. 4  illustrates an example of parameterization of the video  300  according to multiple parameters—the position r  302  and time t  304 . A video segment  310  is determined based on the parameterization of video  330 , and, in particular the sub-sets  320 ,  322  for the respective possible parameter values. The sub-set  320  of position r  302  defines a continuous uninterrupted range and the sub-set  322  of time t  304  defines a continuous uninterrupted range. 
     In addition or alternatively, events that are not clustered may be used to define a video segment. These events are outliers from the clusters and may indicate an unusual atypical event for the time period of the video. 
     A discontinuous transition in a parameter value may be used to determine a start or end of a video segment  310 . 
     A video segment  310  may be referenced by a vector in the parameter space. 
     At block  506 , the method determines which video excerpts, if any, should represent which video segments  310  in an access menu  110 . The video excerpts are used as user-selectable menu options  120  in the access menu  110  that, when selected, access the represented video segment  310 . 
     At block  508 , the method comprises displaying an access menu  110  of video excerpts for selection by a user. User selection of a video excerpt in the access menu  110  activates a link to access a particular video segment or video segments  310 . 
     Where a video segment  310  is represented by a video excerpt in the access menu  110 , then there is typically a one-to-one mapping from the video excerpt to the video segment  310 . For example, the video segment may comprise or be associated with a link to the video segment  310  that is activated when a user selects the video excerpts from the menu  110  causing the video segment to play. 
     The location of the video excerpt in the access menu  110 , is the same as the location of the linked video segment  310 . For example, the parameter position r  302  that parameterizes the video segment  310  may be used to locate the video excerpt in the scene  202  displayed in the access menu  110 . 
     Referring back to  FIG. 1 , the first selectable menu option  120   1  is located at the first location  122   1 , in the scene  202 , and when selected causes access to first video segment(s)  310  that concern activity at the first location  122   1 , in the scene  202 . The first selectable menu option  120   1  is a playing first video excerpt that links to the first video segment(s)  310 . The second selectable menu option  120   2  is located at the second location  122   2 , in the scene  202 , and when selected causes access to second video segment(s)  310  that concern activity at the second location  122   2 , in the scene  202 . The second selectable menu option  120   2  is a playing second video excerpt that links to the second video segment(s)  310 . 
     The video excerpts operating as user selectable menu options  120 , including the first video excerpt  120   1  and the second video excerpt  120   2 , may be simultaneously displayed, while playing at a reduced resolution compared to the linked video segment(s)  310 . 
     The video excerpt s operating as user selectable menu option  120  including the first video excerpt  120   1  and the second video excerpt  120   2  may be displayed in a semi-transparent form overlaying the image  112  of the scene  202 , forming ‘ghost’ images. 
     Each video excerpt may be a short video clip, taken from the video segment  310  it links to, playing in a loop. The user-selection of such a video excerpt may cause playing of the linked video segment  310 . 
     If the video excerpt links to multiple video segments, it may be a concatenation of short video clips, one from each of the linked video segments, playing in a loop. The order of play of the video clips in the loop may be in the same temporal order as the video segments they link to. User-selection of such a video excerpt causes access to the linked video segments, for example, in the form of a menu. Thus multiple video segments for a single location may be represented in the access menu by a single user selectable menu option  120  at a ‘root level’, selection of that user selectable menu option  120  may cause display of multiple user selectable menu options  120 , one for each video segment  310 , at a next level. These multiple user-selectable menu options  120  when selected may cause access to video segments  310  of activity at the same location  122  in the scene  202  at different times. 
       FIG. 6  illustrates an example video that has been parameterized using position r  302  and the time t  304  into events occurring at (t, r).  FIGS. 7A, 7B, 8A, 8B, 8C  illustrate this example video  300  after it has been parameterized using position r  302  and the time t  304  into events occurring at (t, r) and segmentation of the events into distinct video segments  310   n  that occur at (t n , r n ). 
       FIG. 7A  illustrates an example video  300  that has been parameterized using position r  302  and the time t  304  into events occurring at (t, r). It additionally illustrates the segmentation of the events into a first set of distinct video segments  310  comprising video segments  310   1    310   2  at a position r 1  and video segment  310   3  at a position r 3 , The visual access menu  110  for these video segments  310  may comprise a first user-selectable menu option  120   1 , at a first location  122   1  in the scene  202  corresponding to the position r 1 , that when selected causes access to the video segments  310   1    310   2  of activity at the first position r 1  and comprise a second user-selectable menu option  120   2 , at a second location  122   1  in the scene  202  corresponding to the position r 3 , that when selected causes access to the video segments  310   3  of activity at the position r 3 . 
       FIG. 7B  illustrates the video  300 , of  FIG. 7A , but illustrates the segmentation of the events into a different second set of distinct video segments  310 . In this example, the video segment  310   3  at a position r 3  illustrated in  FIG. 7A  has been sub-divided into three different video segments  310   4 ,  310   5 ,  310   6 , at respective positions r 4 , r 5 , r 6 . The visual access menu  110  for these video segments  310  may comprise a first user-selectable menu option  120   1 , at a first location  122   1  in the scene  202  corresponding to the position r 1 , that when selected causes access to the video segments  310   1    310   2  of activity at the first position r 1  and comprise, for each of n=4, 5, 6, a further user-selectable menu option  120   n  at location  122   n  in the scene  202  corresponding to the position r n , that when selected causes access to the video segment  310   n  of activity at the position r n . 
     In the example of  FIG. 7A  a video  300  recording a person or object following route has been segmented into a single video segment  310   3 , whereas in  FIG. 7B  the video  300  recording the person or object following the route has been segmented into a three video segments  310   4 ,  310   5 ,  310   6 . 
       FIG. 8A  illustrates the video  300  of  FIG. 7A , but the video  300  has been parameterized using not only position r  302  and the time t  304  but also person A into events occurring at (t, r) by person A. It illustrates the segmentation of the events into a sub-set of the set of distinct video segments  310  illustrated in  FIG. 7A  comprising video segments  310   1    310   2  at a position r 1  but not video segment  310   3  at position r 3  The visual access menu  110  for these video segments  310   1    310   2  may comprise a first user-selectable menu option  120   1 , at a first location  122   1  in the scene  202  corresponding to the position r 1 , that when selected causes access to the video segments  310   1    310   2  of activity at the first position r 1  by person A. 
       FIG. 8B  illustrates the video  300 , of  FIG. 7A , but the video  300  has been parameterized using position r  302 , the time t  304  and a person B into events occurring at (t, r) by person B. It illustrates the segmentation of the events into a sub-set of the first set of distinct video segments  310  illustrated in  FIG. 7A  comprising video segment  310   3  at a position r 3  but not video segments  310   1    310   2  at a position r 1 . The visual access menu  110  for this video segment  310   3  may comprise a user-selectable menu option  120   2 , at a location  122  in the scene  202  corresponding to the position r 3 , that when selected causes access to the video segment  310   3  of activity at the position r 3  by person B. 
       FIG. 8C  illustrates the video  300 , of  FIG. 7B , but the video  300  has been parameterized using position r  302  and the time t  304  but also person B into events occurring at (t, r) by person B. It illustrates the segmentation of the events into a sub-set of the second set of distinct video segments  310  illustrated in  FIG. 7B  comprising video segments  310   4 ,  310   5 ,  310   6 , at respective positions r 4 , r 5 , r 6 . The visual access menu  110  for these video segments  310  may comprise user-selectable menu options  120   n , at locations  122   n  in the scene  202  corresponding to the position r n , that when selected causes access to the video segments  310   n  of activity at the position r n , where n=4, 5, 6. 
     The  FIGS. 6, 7A-7B and 8A-8C  illustrate parameterization of the video  300  according to at least when and where activity occurs in the video  300  and the determination of video segments  310  based on at least when and where activity occurs in the video  300 . 
       FIGS. 8A, 8B, 8C  illustrate parameterization of the video  300  according to at least when and where activity occurs in video  300  and an additional parameter (who is performing the activity) and the determination of video segments  310  based on at least when and where activity occurs in the video and the additional parameter (who is performing the activity) 
     While in  FIGS. 8A, 8B, 8C  the additional parameter is who is performing the activity, in other examples the additional parameter may be a different parameter or a combination of parameters. For example, the additional parameter may be or include what the activity is. 
     The user may be able to control over which period of time the video  300  is parameterized and therefore over which period of time the video segments  310  are from. A user input control such as, for example, a slider may be used to change this time period. 
     The consequence of changing the time period may be appreciated from  FIG. 7B . Each video segments  310   n  has a position r n    302  and a start time t n    304 . 
       FIG. 7B  illustrates the video  300 , of  FIG. 7A , but illustrates the segmentation of the events into a different second set of distinct video segments  310   4 ,  310   5 ,  310   6 . In this example, one of the video segments  310   3  illustrated in  FIG. 7A  has been sub-divided into three different video segments  310   4 ,  310   5 ,  310   6 . The video  300  comprises video segments  310   1    310   2  at a position r 1  at times t 1 , t 1  and video segments  310   4 ,  310   5 ,  310   6 , at respective positions r 4 , r 5 , r 6  and times at time t 4 , t 5 , t 6 . When the time period is long enough to cover at least times t 1 , t 2 , t 4 , t 5 , t 6 , the visual access menu  110  for these video segments  310  may comprise a first user-selectable menu option  120   1 , at a first location  122   1  in the scene  202  corresponding to the position n, that when selected causes access to the video segments  310   1    310   2  of activity at the first position r 1  and comprise, for each of n=4, 5, 6, a further user-selectable menu option  120   n , at location  122   n  in the scene  202  corresponding to the position r n , that when selected causes access to the video segment  310   n  of activity at the position r n  at time t n . However, when the time period is shortened to cover only times t 1  and t 4  but not times t 2 , t 5 , t 6 , the visual access menu  110  for these video segments  310  may comprise a first user-selectable menu option  120   1 , at a first location  122   1  in the scene  202  corresponding to the position n, that when selected causes access to the video segments  310   1  of activity at the first position r 1  at time t 1 , and comprise a further user-selectable menu options  1204 , at location  1224  in the scene  202  corresponding to the position r 4 , that when selected causes access to the video segments  310   4  of activity at the position r 4  at time t 4 . 
     As described above in relation to  FIG. 5 , image processing may be used to parameterize the videos  300 . Image processing may be used to recognise an event in the videos  300  and features of the event may be used as parameters. 
     The event features may for example be activity in the scene  202 , recognition of a particular user or object, recognition of an interaction between two or more persons or objects, recognition of a particular action or activity such as following a route to or from a location, etc. 
     The occurrence of the event may be logged as occurring at position r and at time tin the video  300 , causing parameterization of the video  300  according to at least when and where an event occurs in the video  300 . 
     An event may be a combination of one of more different alternatives such as: a particular activity in the scene  202 /any activity in the scene  202 ; by a particular person/by any person; in relation to a particular object/not in relation to a particular object. 
     Parameterization of the video  300  may be according to when and where any activity occurs in the video  300  and additionally according to one or more additional parameters which may include: 
     what the activity is; who or what is performing the activity; who or what the activity is performed in relation to. 
     Events that occur sequentially in time and are clustered according to position and, optionally, one or more of the additional parameters, may be used to define a video segment  310 . These events are inliers within the cluster and may indicate a usual prototypical event for the time period of the video. 
     A subject-specific event may be a combination of events such as (any) activity in the scene  202  by a particular person causing subject-specific parameterization of the video  300  according to when and where any activity occurs in the video  300  and additionally, at least, who or what is performing the activity. 
     An object-specific event may be a combination of events such as (any) activity in the scene  202  in relation to a particular object causing object-specific parameterization of the video  300  according to when and where any activity occurs in the video and additionally, at least who or what the activity is performed in relation to. 
     An activity-specific event may be a combination of events such as a particular activity in the scene  202  by any person or in relation to any object, causing activity-specific parameterization of the video  300  according to when and where activity occurs in video and additionally, at least, what the activity is. 
     The parameters used for parameterization of the video  300  may a fixed set of parameters or a variable set of parameters. For example, a user may be able to determine one or more or all of the parameters used for parameterization of the video or videos  300 . 
     User-selection of a user-selectable menu options  120   n  may cause a change in the additional parameter(s) or a constraint of existing parameters, resulting in new parameterization of the video, new clustering and a new visual access menu  110  comprising new user-selectable menu options  120   n . The different locations of user-selectable menu options  120   n  in the visual access menu  110  may enable by user selection different constraints of an additional parameter such as the subject, the location, the activity or the time. 
     By performing user-selection of user-selectable menu options  120   n  in a sequential series of visual access menus  110  the user may sequentially constrain the parameters, resulting in increasingly specific parameterization of the video  300 , increasingly specific clustering and an increasingly specific visual access menu  110  comprising user-selectable menu options  120   n . The sequential constraints may be used to enable by sequential user selection from sequential visual access menus  110  different constraints of multiple additional parameters such as a combination of the subject, the location, the activity and the time. 
       FIGS. 11A, 11B, 11C, 11D  illustrate a ‘subject-specific’ parameterization of the video  300  according to when and where any activity occurs in the video and additionally, at least, who or what is performing the activity. 
       FIG. 11A  illustrates a displayed panoramic scene  112  of the video  300 . This displayed scene includes two possible subjects a first subject (a baby) to the left and a second subject (a man) to the right. It may be a visual access menu  110  user-selectable menu options  120   n  for different subjects. 
     When one of the subjects is selected by, for example, a user touching the display portion corresponding to the subject, then the method  100  is performed and provides a visual access menu  110  as illustrated in  FIG. 11B  that enables a user to access video segments  310  of the scene  202 . Different user-selectable menu options  120   n  are displayed at different locations in the scene  112 . The different locations represent different locations (and times). Selection of a particular user-selectable menu option causes access to one or more first video segments  310  of activity at that location  122   1  in the scene  202 . 
     In the example illustrated, in  FIG. 11B , the user-selectable menu option  1204  is selected. 
     Where one video segment is associated with this subject at this location, that video segment  310  is played to the user as illustrated in  FIG. 11C . 
     Where multiple different temporally distinct video segments  310  are associated with this subject at this location, the video  300  is re-parameterised as described in relation to, for example,  FIG. 7B  to convert the menu option  120   5  in  FIG. 11B  that represents multiple video segments at that location at different times into multiple user-selectable menu option  120   m  in  FIG. 11D  that each represent a video segment  310  at that location at a different time. The method  100  may, for example, be re-performed but constrained only to events for the selected subject at the selected location, to provide a visual access menu  110  as illustrated in  FIG. 11D  that enables a user to access video segments  310  of the scene  202 . Different user-selectable menu options  120   n  are displayed at different locations in the scene  112 . The different locations represent different times. Selection of a particular user-selectable menu option causes access to one or more video segments  310  of activity by the selected subject, at that location in the scene  202 , at different times. 
     Therefore user selection at  FIG. 11A  selects the subject, user-selection at  FIG. 11B  selects the location and user selection at  FIG. 11D  selects the time. 
     In for example,  FIGS. 11B and 11D , there is simultaneous display, at a first location  122   n  in the scene  202 , of a first user-selectable menu option  120   n  that when selected causes access to one or more first video segments  310  of activity by the selected subject at the first location  122   n  in the scene  202  and, at a second location  122   m  in the scene  202 , of a second user-selectable menu option  120   m  that when selected causes access to one or more second video segments  310  of activity by the selected subject at the second location  122   m  in the scene  202 . 
       FIGS. 12A and 12B  illustrate an ‘object-specific’ parameterization of the video  300  according to when and where any activity occurs in the video and additionally, at least, who or what the activity is performed in relation to. 
       FIG. 11A  illustrates a displayed panoramic scene  112  of the video  300 . This displayed scene includes possible objects including locations (not illustrated). 
     When one of the objects is selected by, for example, touching the display portion corresponding to the object, then the method  100  is performed and provides a visual access menu  110  as illustrated in  FIG. 12A or 12B  that enables a user to access video segments  310  of the scene  202  for the selected object. Different user-selectable menu options  120   n  are displayed at different locations in the scene  112 . Selection of a particular user-selectable menu option causes access to one or more first video segments  310  of activity at that location  122   1  in the scene  202 . 
     The parameterization of the video  300  is performed automatically in respect of which subjects have interacted with the selected object. This creates clusters of events and corresponding video segments  310 . One cluster of video segments  310  relates to the selected object and the first subject. These video segments  310  are represented by corresponding user-selectable menu options  120   n  ( FIG. 12A ). Another cluster of video segments  310  relates to the selected object and the second subject. These video segments  310  are represented by corresponding user-selectable menu options  120   n  ( FIG. 12B ). 
       FIG. 12A  illustrates a visual access menu  110  that comprises multiple user-selectable menu options  120   n  that are displayed at different locations in the scene  112  for video segments  310  relating to interaction of a first subject with a user-selected object at different times. The different locations represent different times. Selection of a particular user-selectable menu option  120   n  causes access to one or more video segments  310  of activity relating to the selected object and the first subject in the scene  202 , at different times. 
       FIG. 12B  illustrates a visual access menu  110  that comprises multiple user-selectable menu options  120   n  that are displayed at different locations in the scene  112  for video segments  310  relating to interaction of a second subject with a user-selected object at different times. The different locations represent different times. Selection of a particular user-selectable menu option  120   n  causes access to one or more video segments  310  of activity relating to the selected object and the second subject in the scene  202 , at different times. 
     An automatic selection criteria may be used to decide whether to present the visual access menu  110  associated with the first subject ( FIG. 12A ) or the second subject ( FIG. 12B ). In this example, the criteria used is the number of clusters (video segments  310 ). As the visual access menu  110  associated with the first subject ( FIG. 12A ) has more user-selectable menu options  120   n  it is displayed first. The user may provide a user input to cause display of the visual access menu  110  associated with the second subject ( FIG. 12B ) 
     Therefore selection at  FIG. 11A  selects the object and user selection at  FIGS. 12A / 12 B selects the subject and time. 
     There may be display, at a first location  122   n  in the scene  202 , of a first user-selectable menu option  120   n  that when selected causes access to one or more first video segments  310  of activity in relation to a selected object at the first location  122   n  in the scene  202  and, at a second location  122   m  in the scene  202 , of a second user-selectable menu option  120   m  that when selected causes access to one or more second video segments  310  of activity in relation to the selected object. These may be displayed simultaneously as illustrated in  FIG. 12A  or  FIG. 12B  and/or may be sequentially as illustrated in the switch from  FIG. 12A  to  FIG. 12B . 
       FIGS. 11A and 13A, 13B  illustrate an ‘activity-specific’ parameterization of the video  300  according to when and where any activity occurs in the video and additionally, at least, what the activity is that is performed. 
       FIG. 11A  illustrates a displayed panoramic scene  112  of the video  300 . 
     When an activity is selected by a user or automatically, then the method  100  is performed and provides a visual access menu  110  as illustrated in  FIG. 13A or 13B  that enables a user to access video segments  310  of the scene  202 . Different user-selectable menu options  120   n  are displayed at different locations in the scene  112 . The different locations represent different locations (and times). Selection of a particular user-selectable menu option  120   n  causes access to one or more first video segments  310  of activity at that location  122   n  in the scene  202 . 
     The parameterization of the video  300  is performed automatically in respect of the selected activity. This creates a cluster of events and corresponding video segments  310  that include the selected activity and these video segments  310  are represented by corresponding user-selectable menu options  120   n . 
     The activity may or may not be subject specific. 
       FIG. 12A  illustrates a visual access menu  110  that comprises multiple user-selectable menu options  120   n  that are displayed at different locations in the scene  112  for video segments  310  relating to movement of a first subject at different locations/times. Selection of a particular user-selectable menu option  120   n  causes access to one or more video segments  310  of activity relating to the movement of the first subject in the scene  202 , at different locations/times. 
       FIG. 12B  illustrates a visual access menu  110  created after the user-selectable menu options  120   3  has been selected. The visual access menu  110  comprises multiple user-selectable menu options  120   m  that are displayed at different locations in the scene  112  for video segments  310  relating to movement of the first subject at different locations/times. Selection of a particular user-selectable menu option  120   m  causes access to one or more video segments  310  of activity relating to the elected object and the first subject in the scene  202 , at different locations/times. 
     Therefore selection at  FIG. 11A  selects the activity, and user-selection at  FIG. 13A  selects the location/time. 
     There may be display, at a first location  122   n  in the scene  202 , of a first user-selectable menu option  120   n  that when selected causes access to one or more first video segments  310  of activity in relation to a selected activity at the first location  122   n  in the scene  202  and, at a second location  122   m  in the scene  202 , of a second user-selectable menu option  120   m  that when selected causes access to one or more second video segments  310  of activity in relation to the selected activity. These may be displayed simultaneously as illustrated in  FIG. 13A  and/or may be displayed sequentially as illustrated in the switch from  FIG. 13A  to  FIG. 13B . 
     In the example of  FIG. 13A , the visual access menu  110  comprises multiple user-selectable menu options  120   n  for different waypoints along a route taken by the first subject. 
     In the example of  FIG. 13B , after one of the waypoint user-selectable menu options  120   n  has been selected by a user, the visual access menu  110  comprises multiple user-selectable menu options  120   n  for different waypoints along different routes taken by the first subject. 
     The selection of a user-selectable menu option  120   n  in  FIG. 13A  may cause the video  300  to be re-parameterised as described in relation to, for example,  FIG. 7B  to convert the visual access menu  110  in  FIG. 13A  that represents multiple video segments  130  for movement of the first subject during a time period T 1  into the visual access menu  110  in  FIG. 13B  that represents multiple video segments  130  for movement of the first subject during subsequent different time period T 2 . Thus selecting different user-selectable menu option  120   n  illustrated as→may change the time period used to generate user-selectable menu option  120   n  and selecting user-selectable menu option  120   n  illustrating the first subject may cause playback of a video segment  310 . 
     Referring to  FIG. 5  the method  500  may in some but not necessarily all examples comprise the following blocks: 
     (i) obtain one or more videos 
     (ii) obtain key objects from the videos 
     (iii) obtain key locations and/or activities from the videos 
     (iv) obtain key routes from the videos 
     (v) create a summary video by superimposing the key object performing the key activities at the key locations on the background 
     (vi) enable user to interact with a representation of the key object along a route 
     (vii) obtain a new set of summary videos from the set of videos where the object has moved along the route 
     (viii) create a summary video display by superimposing the object on continued route visualizations. 
     The block (ii) corresponds to subject-specific parameterization of the video (including when and where any activity occurs in the video)—see  FIGS. 8A-8C, 10-13 . 
     The block (iii) corresponds to object-specific parameterization of the video ( FIGS. 12A-12B ) and/or activity-specific parameterization of the video ( FIG. 13A-13B ). 
     The block (iv) corresponds to parameterization of the video where the activity relates to a route ( FIG. 13A-13B ). 
     The block (v) corresponds to displaying the visual access menu  110  using the superimposed key object as user-selectable menu options  120   n . 
     The block (vi) corresponds to user selection of a user-selectable menu option  120   n  from the displayed the visual access menu  110 . 
     The block (vii) corresponds to generation of a new visual access menu  110  which may be based on re-parameterization of the video  300  using constraints defined by the user selection to define new clusters of video segments  310  and corresponding new user-selectable menu options  120   n . In this case, the constraint is a position along a route. 
     The block (viii) corresponds to displaying the new visual access menu  110  using the superimposed key object as new user-selectable menu options  120   n . In this case the new user-selectable menu options  120   n  relate to the key object moving along the route. 
     It will be appreciated from the foregoing that the parameterization and clustering defines a visual access menu with user-selectable menu options  120   n . The menu structure is such that the user can via one or more menu levels access and play a particular video segment  310 . The menu structure is dependent upon the parameterization and segmentation which may be recalculated whenever the user accesses a user-selectable menu options  120   n  that further specifies the parameterization as opposed to playing a video segment  310 . The user is therefore able to zoom-in on and select for playing a video segment by constraining sequentially parameters such as the subject, the object, the activity, the location, the time (see  FIGS. 11, 12, 13 ). 
     The methods  100 ,  500  described above in relation to  FIGS. 1-8  may be performed by a controller  801 . Implementation of the controller  801  may be as controller circuitry. The controller  801  may be implemented in hardware alone, have certain aspects in software including firmware alone or can be a combination of hardware and software (including firmware). 
     As illustrated in  FIG. 9  the controller  801  may be implemented using instructions that enable hardware functionality, for example, by using executable computer program instructions  806  in a general-purpose or special-purpose processor  802  that may be stored on a computer readable storage medium (disk, memory etc) to be executed by such a processor  802 . 
     The processor  802  is configured to read from and write to the memory  804 . The processor  802  may also comprise an output interface via which data and/or commands are output by the processor  802  and an input interface via which data and/or commands are input to the processor  802 . 
     The memory  804  stores at least a computer program  806  comprising computer program instructions (computer program code) that controls the operation of the apparatus  800  when loaded into the processor  802 . The computer program instructions, of the computer program  806 , provide the logic and routines that enables the apparatus to perform the methods  100 ,  500  illustrated in  FIGS. 1-8 . The processor  802  by reading the memory  804  is able to load and execute the computer program  806 . 
     The controller  801  is configured to receive the video  300  for processing. 
     The controller  801  is configured to receive user input via a user input device or devices  812 . 
     The controller is configured to provide user output via the display  810 . 
     The display  810  may be a visual display. Examples of visual displays include liquid crystal displays, organic light emitting displays, emissive, reflective and transflective displays, direct retina projection display, near eye displays etc. 
     The user input device  812  comprises circuitry that detects user actions. The detected user actions may, for example, be gestures performed in a real space. Gestures may be detected in a number of ways. For example, depth sensors may be used to detect movement of parts a user and/or or image sensors may be used to detect movement of parts of a user and/or positional/movement sensors attached to a limb of a user may be used to detect movement of the limb. 
     The apparatus  800  may used to provide “mediated reality” to a user. This refers to a user visually experiencing a fully or partially artificial environment (a virtual space) as a virtual scene at least partially displayed by a computer to a user. The virtual scene is determined by a point of view within the virtual space and a field of view. Displaying the virtual scene means providing it in a form that can be seen by the user. The apparatus  800  may be an “augmented reality” apparatus. Augmented reality is a form of mediated reality in which a user visually experiences a partially artificial environment (a virtual space) as a virtual scene comprising a real scene of a physical real world environment (real space) supplemented by one or more visual elements displayed by an apparatus to a user. The apparatus  800  may be a “virtual reality” apparatus. Virtual reality is a form of mediated reality in which a user visually experiences a fully artificial environment (a virtual space) as a virtual scene displayed by an apparatus to a user; 
     The display  810  may be a visual display that provides light that displays at least parts of a virtual scene to a user. 
     The apparatus  800  may, for example, be a handheld apparatus comprising a display screen as display  810 . The handheld apparatus may be or may be operated as a see-video arrangement for augmented reality that enables a live or recorded video of a real scene to be displayed on the display  810  for viewing by the user while one or more visual elements are simultaneously displayed on the display for viewing by the user. The combination of the displayed real scene and displayed one or more visual elements provides a virtual scene to the user. 
     The apparatus  800  may be a head-mounted apparatus. The head-mounted apparatus  800  may be a see-through arrangement for augmented reality that enables a live real scene to be viewed while one or more visual elements are displayed by the display to the user to provide in combination a virtual scene. In this case a visor, if present, is transparent or semi-transparent so that the live real scene  202  can be viewed through the visor. 
     The head-mounted apparatus may be operated as a see-video arrangement for augmented reality that enables a live or recorded video of a real scene to be displayed by the display  810  for viewing by the user while one or more visual elements are simultaneously displayed by the display  810  for viewing by the user. The combination of the displayed real scene and displayed one or more visual elements provides a virtual scene to the user. In this case a visor is opaque and may be used as the display  810 . 
     The apparatus  800  may therefore comprise: at least one processor  802 ; and at least one memory  804  including computer program code  806  the at least one memory  804  and the computer program code  806  configured to, with the at least one processor  802 , cause the apparatus  800  at least to perform: causing provision of a visual access menu to enable a user to access video segments of a scene comprising: causing display of an image of the scene; causing display, at a first location in the scene, of a first user-selectable menu option that when selected causes access to one or more first video segments of activity at the first location in the scene; and causing display, at a second location in the scene, of a second user-selectable menu option that when selected causes access to one or more second video segments of activity at the second location in the scene. 
     As illustrated in  FIG. 10 , the computer program  806  may arrive at the apparatus  800  via any suitable delivery mechanism  820 . The delivery mechanism  820  may be, for example, a non-transitory computer-readable storage medium, a computer program product, a memory device, a record medium such as a compact disc read-only memory (CD-ROM) or digital versatile disc (DVD), an article of manufacture that tangibly embodies the computer program  806 . The delivery mechanism may be a signal configured to reliably transfer the computer program  806 . The apparatus  800  may propagate or transmit the computer program  806  as a computer data signal. 
     Although the memory  804  is illustrated as a single component/circuitry it may be implemented as one or more separate components/circuitry some or all of which may be integrated/removable and/or may provide permanent/semi-permanent/dynamic/cached storage. 
     Although the processor  802  is illustrated as a single component/circuitry it may be implemented as one or more separate components/circuitry some or all of which may be integrated/removable. The processor  802  may be a single core or multi-core processor. 
     References to ‘computer-readable storage medium’, ‘computer program product’, ‘tangibly embodied computer program’ etc. or a ‘controller’, ‘computer’, ‘processor’ etc. should be understood to encompass not only computers having different architectures such as single/multi-processor architectures and sequential (Von Neumann)/parallel architectures but also specialized circuits such as field-programmable gate arrays (FPGA), application specific circuits (ASIC), signal processing devices and other processing circuitry. References to computer program, instructions, code etc. should be understood to encompass software for a programmable processor or firmware such as, for example, the programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device etc. 
     As used in this application, the term ‘circuitry’ refers to all of the following: 
     (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and 
     (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and
 
(c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of ‘circuitry’ applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term “circuitry” would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term “circuitry” would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or other network device.
 
     The blocks illustrated in the  FIG. 5  may represent steps in a method and/or sections of code in the computer program  806 . The illustration of a particular order to the blocks does not necessarily imply that there is a required or preferred order for the blocks and the order and arrangement of the block may be varied. Furthermore, it may be possible for some blocks to be omitted. 
     Where a structural feature has been described, it may be replaced by means for performing one or more of the functions of the structural feature whether that function or those functions are explicitly or implicitly described. 
     The controller  801  comprises: means for causing display of at least a portion of an image of a scene; means for causing display, at a first location in the scene, of a first user-selectable menu option that when selected causes access to one or more first video segments of activity at the first location in the scene; and means for causing display, at a second location in the scene, of a second user-selectable menu option that when selected causes access to one or more second video segments of activity at the second location in the scene. 
     The apparatus  800  comprises: means for displaying at least a part of an image of the scene; means for displaying, at a first location in the scene, first user-selectable menu option; means for displaying, at a second location in the scene, a second user-selectable menu option; means responsive to user selection of the first user-selectable menu option to provide access to one or more first video segments of activity at the first location in the scene; and means responsive to user selection of the second user-selectable menu option to provide access to one or more second video segments of activity at the second location in the scene. 
     The term ‘comprise’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to “comprising only one.” or by using “consisting”. 
     In this brief description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus ‘example’, ‘for example’ or ‘may’ refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a features described with reference to one example but not with reference to another example, can where possible be used in that other example but does not necessarily have to be used in that other example. 
     Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. 
     Features described in the preceding description may be used in combinations other than the combinations explicitly described. 
     Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. 
     Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not. 
     Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.