Patent Publication Number: US-2022236807-A1

Title: Method and apparatus for a three dimensional interface

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/169,594, filed May 31, 2016, which is hereby incorporated by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The disclosure relates to navigating within and/or controlling systems with free space pose input. The disclosure relates more particularly using a single free space pose in several different postures, wherein each posture calls a different function, so as to enable control of an electronic device or another system. 
     DESCRIPTION OF RELATED ART 
     An input to a system may be delivered in a variety of manners. For example, free space inputs not constrained to a surface such as a mouse pad, touch screen, etc.—may be delivered with a human hand, stylus, etc. Such inputs then may be sensed, with responses carried out based on the hand inputs (or stylus inputs, etc.). 
     Certain types of interface may facilitate a very large number of unique individual inputs, for example e.g. 100 or more keys for certain desktop PCs, a nearly unlimited number of potential text commands, etc. However, free space inputs may in at least certain circumstances have a more limited range of unique inputs available, or at least a more limited range of inputs that are useful in practice. For example, even though extending an index finger while leaving other fingers clenched may be straightforward for many individuals, similarly extending a ring finger while leaving other fingers clenched may be much more difficult. In addition, certain inputs may be difficult to identify from sensor data, e.g. the index and middle finger extended while held together may, to certain sensors and from certain angles, exhibit an appearance similar to an index finger extended alone. 
     In principle, it may be possible to provide a greater number of available inputs by considering degrees of variation. For example, several degrees of extension of an index finger could each be assigned different meanings (e.g. calling different commands). Potentially, this could provide for a very large number of possible free space hand inputs. However, doing so could raise issues of definition and discrimination in recognizing the inputs (for example, determining whether the index finger is fully extended, half extended, quarter extended, etc.), and could also serve to confuse users (who would have to remember the difference between what a fully extended index finger means versus a half extended index finger). 
     BRIEF SUMMARY OF THE INVENTION 
     The embodiments are directed to a variety of systems, apparatus, methods, and paradigms for using poses in varying postures for integrated system control and/or navigation. 
     In one embodiment, a method is provided that includes instantiating a forward interface navigation function including a forward scrolling of content in a processor, instantiating a back interface navigation function including a backward scrolling of the content opposed to the positive scrolling in the processor, instantiating an affirmative interface navigation function including a logical affirmative in the processor, and instantiating a negative interface navigation function including a logical negative opposed to the logical affirmative in the processor. The method includes defining a substantially horizontal geometric directional axis in the processor and defining a substantially vertical geometric directional axis in the processor. The method also includes instantiating a forward posture input standard associated with the forward interface navigation function in the processor, specifying a free space hand pose including fingers substantially together and substantially clenched and thumb substantially extended and substantially raised, with the hand pose being disposed in forward posture with the thumb oriented substantially rightward along the horizontal axis, instantiating a back posture input standard associated with the back interface navigation function in the processor, specifying the hand pose disposed in a back posture with the thumb oriented substantially leftward along the horizontal axis, instantiating an affirmative posture input standard associated with the affirmative interface navigation function in the processor, specifying the hand pose disposed in an affirmative posture with the thumb oriented substantially upward along the vertical axis, and instantiating a negative posture input standard associated with the negative interface navigation function in the processor, specifying the hand pose disposed in a negative posture with the thumb oriented substantially downward along the vertical axis. The method further includes sensing a free space hand posture input in a sensor in communication with the processor. If the free space hand posture input satisfies the forward posture input standard, the method includes executing in the processor the forward interface navigation function so as to forward scroll the content. If the free space hand posture input satisfies the back posture input standard, the method includes executing in the processor the back interface navigation function so as to backward scroll the content. If the free space hand posture input satisfies the affirmative posture input standard, the method includes executing in the processor the affirmative interface navigation function so as to indicate the logical affirmative. If the free space hand posture input satisfies the negative posture input standard, the method includes executing in the processor the negative interface navigation function so as to indicate the logical negative. In such manner, the method enables system navigation control with the free space hand posture input. 
     In another embodiment, a method is provided that includes establishing a first control function including a positive parameter progression, establishing a second control function including a negative parameter progression opposed to the positive parameter progression, establishing a third control function including a first logical binary state, and establishing a fourth control function including a second logical binary state opposed to the first logical binary state. The method includes establishing a first axis and establishing a second axis. The method also includes establishing a first input standard associated with the first control function and specifying a pose disposed in a first posture oriented substantially in a first direction along the first axis, establishing a second input standard associated with the second control function and specifying the pose disposed in a second posture oriented substantially in a second direction along the first axis, establishing a third input standard associated with the third control function and specifying the pose disposed in a third posture substantially in a third direction along the second axis, and establishing a fourth input standard associated with the fourth control function and specifying the pose disposed in a fourth posture oriented substantially in a fourth direction along the second axis. The method includes sensing a posture input. The method includes executing the first control function so as to positively progress the parameter if the posture input satisfies the first input standard, executing the second control function so as to negatively progress the parameter if the posture input satisfies the second input standard, executing the third control function so as to indicate the first logical binary state if the posture input satisfies the third input standard, and executing the fourth control function so as to indicate the second logical binary state if the posture input satisfies the fourth input standard. In such manner, the method enables control with the posture input. 
     The parameter may be discrete. The parameter may be continuous. 
     The parameter may include a spatial position, a numeric position, a magnitude, and/or a time. 
     The parameter may include a spatial position within a continuous range of content, with positive parameter progression including forward scrolling the content negative parameter progression including backward scrolling content. 
     The parameter may include a numeric position within a discrete range of content, with the positive parameter progression including forward incrementing the content the negative parameter progression including backward incrementing the content. 
     The first logical binary state may include a logical affirmative, and the second logical binary state may include a logical negative. 
     The first and second directional axes may be geometric axes. The first and second directional axes may be substantially perpendicular. The first geometric direction axis may be substantially horizontal, and the second geometric directional axis may be substantially vertical. 
     The pose may be a free space pose. The pose may be a hand pose. 
     The pose may be a free space hand pose, the pose including fingers substantially together and substantially clenched and thumb substantially extended and substantially raised, with the direction of the thumb defining the orientation of the pose for the posture thereof; fingers and thumb substantially together and substantially extended, with the direction of the fingers and the thumb defining the orientation of the pose for the posture thereof; thumb, middle, index, and pinkie fingers substantially together and substantially clenched and index finger substantially extended, with the direction of the index finger defining the orientation of the pose for the posture thereof; and/or fingers and thumb substantially together and substantially clenched to form a fist, with the direction of the first defining the orientation of the pose for the posture thereof. 
     In another embodiment, a method is provided that includes establishing a first control function including a positive parameter progression and establishing a second control function including a negative parameter progression as opposed to the positive parameter progression. The method includes establishing a directional axis. The method also includes establishing a first input standard associated with the first control function, specifying a pose disposed in a first posture oriented substantially in a first direction along the axis, and establishing a second input standard associated with the second control function, specifying the pose disposed in a second posture oriented substantially in a second direction along the axis. The method includes sensing a posture input. The method further includes executing the first control function so as to positively progress the parameter if the posture input satisfies the first input standard, and executing the second control function so as to negatively progress the parameter if the posture input satisfies the second input standard. In such manner, the method enables control with the posture input 
     The parameter may be discrete. The parameter may be continuous. 
     The parameter may include a spatial position, a numeric position, a magnitude, and/or a time. 
     The parameter may include a spatial position within a continuous range of content, with positive parameter progression including forward scrolling the content negative parameter progression including backward scrolling content. 
     The parameter may include a numeric position within a discrete range of content, with the positive parameter progression including forward incrementing the content the negative parameter progression including backward incrementing the content. 
     The directional axis may be a geometric axis. The geometric directional axis may be substantially horizontal. 
     The pose may be a free space pose. The pose may be a hand pose. 
     The pose may be a free space hand pose, the pose including fingers substantially together and substantially clenched and thumb substantially extended and substantially raised, with the direction of the thumb defining the orientation of the pose for the posture thereof; fingers and thumb substantially together and substantially extended, with the direction of the fingers and the thumb defining the orientation of the pose for the posture thereof; thumb, middle, index, and pinkie fingers substantially together and substantially clenched and index finger substantially extended, with the direction of the index finger defining the orientation of the pose for the posture thereof; and/or fingers and thumb substantially together and substantially clenched to form a fist, with the direction of the first defining the orientation of the pose for the posture thereof. 
     In another embodiment, an apparatus is provided that includes a processor and a sensor in communication with the processor. The processor is adapted to establish a first control function including a positive parameter progression, a second control function including a negative parameter progression opposed to the positive parameter progression, a third control function including a first logical binary state, and a fourth control function including a second logical binary state opposed to the first logical binary state. The processor is adapted to establish a first directional axis and a second directional axis. The processor is also adapted to establish a first input standard associated with the first control function specifying a pose disposed in a first posture oriented substantially in a first direction along the first axis, a second input standard associated with the second control function and specifying the pose disposed in a second posture oriented substantially in a second direction along the first axis, a third input standard associated with the third control function and specifying the pose disposed in a third posture substantially in a third direction along the second axis, and a fourth input standard associated with the fourth control function and specifying the pose disposed in a fourth posture oriented substantially in a fourth direction along the second axis. The sensor is adapted to sense a posture input. The processor is further adapted to execute the first control function so as to positively progress the parameter if the posture input satisfies the first input standard, to execute the second control function so as to negatively progress the parameter if the posture input satisfies the second input standard, to execute the third control function so as to indicate the first logical binary state if the posture input satisfies the third input standard, and to execute the fourth control function so as to indicate the second logical binary state if the posture input satisfies the fourth input standard. In such a manner, the apparatus is adapted to enable system control with the posture input. 
     In another embodiment, an apparatus is provided that includes means for establishing a first control function including a positive parameter progression, a second control function including a negative parameter progression opposed to the positive parameter progression, a third control function including a first logical binary state, and a fourth control function including a second logical binary state opposed to the first logical binary state. The apparatus includes means for establishing a first directional axis and a second directional axis. The apparatus also includes means for establishing a first input standard associated with the first control function and specifying a pose disposed in a first posture oriented substantially in a first direction along the first axis, a second input standard associated with the second control function and specifying the pose disposed in a second posture oriented substantially in a second direction along the first axis, a third input standard associated with the third control function and specifying the pose disposed in a third posture substantially in a third direction along the second axis, and a fourth input standard associated with the fourth control function and specifying the pose disposed in a fourth posture oriented substantially in a fourth direction along the second axis. The apparatus includes means for sensing a posture input. The apparatus further includes means for executing the first control function so as to positively progress the parameter if the posture input satisfies the first input standard, executing the second control function so as to negatively progress the parameter if the posture input satisfies the second input standard, executing the third control function so as to indicate the first logical binary state if the posture input satisfies the third input standard, and executing the fourth control function so as to indicate the second logical binary state if the posture input satisfies the fourth input standard. In such a manner, the apparatus enables system control with the posture input. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Like reference numbers generally indicate corresponding elements in the figures. 
         FIG. 1A  and  FIG. 1B  show an example hand pose exhibiting two different example postures. 
         FIG. 2A  and  FIG. 2B  show example input axes and example postures arranged with respect thereto. 
         FIG. 3A  and  FIG. 3B  show an example method for controlling a system, in flow chart form. 
         FIG. 4A  through  FIG. 4D  show example first, second, third, and fourth inputs as postures of a thumb-extended pose, in perspective view. 
         FIG. 5A  through  FIG. 5D  show example first, second, third, and fourth inputs as postures of a thumb-extended pose, in end-on view. 
         FIG. 6A  through  FIG. 6D  show example ranges of alignment degeneracy for postures, in schematic view. 
         FIG. 7A  through  FIG. 7E  show examples of the degeneracy of pose, in perspective view. 
         FIG. 8A  and  FIG. 8B  show example variations of postures as may be considered for input, in perspective view. 
         FIG. 9A  and  FIG. 9B  show example variations of postures as may be rejected for input, in perspective view. 
         FIG. 10A  through  FIG. 10C  show additional example poses, in perspective view. 
         FIG. 11A  and  FIG. 11B  show another example method for controlling a system particular to a thumb-extended hand pose with cardinal postures, in flow chart form. 
         FIG. 12  show another example method for controlling a system particular to a thumb-extended hand pose with a pair of opposed postures, in flow chart form. 
         FIG. 13  shows an example apparatus for controlling a system, in schematic view. 
         FIG. 14  shows an example embodiment of an apparatus for controlling a system, in particular a head-mounted display, in perspective view. 
         FIG. 15  shows a block diagram of a processing system that may implement certain example operations as described. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made herein to poses and postures. While colloquially the terms may be considered similar (and in some instances may even be used interchangeably), as used herein the terms “pose” and “posture” refer to two related but distinct notions. 
     A pose refers to an internal configuration. For example, for a hand, a pose includes which digits are extended, which are curled, whether digits are spread or angled, and so forth. Overall orientation with regard to the external world is not considered in defining a pose. For example, with reference to  FIG. 1A , a hand  102 A is shown therein with digits  104 A,  106 A,  108 A,  110 A, and  112 A extended and held together. Also with reference to  FIG. 1B , a hand  102 B again is shown therein with digits  104 B,  106 B,  108 B,  110 B, and  112 B extended and held together. In  FIG. 1A  the hand  102 A is oriented with the palm thereof facing downward; in  FIG. 1B  the hand  102 B is oriented with the palm thereof facing to the left. However, even though the orientation of the two hands  102 A and  102 B is different, the internal configuration is the same. Thus, the hands  102 A and  102 B have the same pose. 
     By contrast, posture also considers the orientation of a hand (or other entity) with regard to some frame of reference external to that hand. The hands  102 A and  102 B in  FIG. 1A  and  FIG. 1B  do not show the same posture, because the hand  102 A in  FIG. 1A  is arranged palm down, while the hand  102 B in  FIG. 1B  is arranged palm left. 
     Thus, two particular hands may exhibit the same pose, but different postures, as is the case with the hands in  FIG. 1A  and  FIG. 1B . However, two hands with different poses are not considered to be the same posture. For example, if the hand  102 A in  FIG. 1A  were clenched into a first without rotating or otherwise moving, that first then would still be considered a different posture (and also a different pose) than the hand  102 A as shown in  FIG. 1A . 
     A distinction between poses and postures may be useful in at least certain instances. For example, when considering the interpretation of inputs, e.g. using machine-implemented approaches such as by machine vision, it may be convenient to reduce possible inputs to relatively fundamental features. For example, pose and posture may be considered separately, with all first postures potentially being the same pose (assuming no consideration is given as to how the first is made, e.g. whether the thumb is on the outside or the inside). Rather than attempting to identify many “different” inputs based on whether a first is upright or inverted, pointing left, straight ahead, right, up, down, etc., all such inputs may be considered as a single pose (“fist”) and the variations distinguished based on orientation/direction. Thus, the distinction between pose and posture may support computational simplicity. 
     The pose/posture distinction also may support simplicity for users. For example, a user who intends to deliver input with a first may not have to consider how to make a first pointing to the right as being a distinct process from making a first pointing to the left. For the user, both may represent “making a fist”, with the direction being a separate but simple factor. 
     Such an arrangement illuminates a notable advantage of certain embodiments disclosed herein. Namely, for a system of navigation that uses a single pose (or even a related group of poses) in several postures to deliver several different inputs, the user may utilize such an arrangement intuitively. If basic navigation is carried out with several postures, those postures exhibiting a single pose but in different orientations, such an arrangement may prove simple and/or intuitive to users. As a more concrete example, if all (or even several) core navigation functions within a user interface all use (for instance) some variation on the “thumbs up” pose, the user may find such an arrangement relatively intuitive and easy to remember and use. 
     Moreover, if the system interpreting the inputs may be designed with the expectation that poses for certain basic inputs will be restricted to a single pose, then even if several different postures of that pose may be delivered the use of a single pose may simplify the task of determining what inputs have been delivered. To continue the example above, if a system is designed so that all (or even several) core navigation functions within a user interface use the single “thumbs up” pose in a variety of postures, then distinguishing inputs may not require determining what pose is being implemented; rather, it may be assumed to be true (or at least likely) that a given input is the “thumbs up” pose, with only the matter of the orientation of that pose (the posture) left to be determined. 
     However, such advantages are examples only, and should not be considered as limiting. Other advantages and/or other arrangements may be present in addition to or instead of those noted above as examples. 
     Likewise, for purposes of certain descriptions herein, the use of the “thumbs up” is presented as an example pose, in various postures (e.g. thumb up, thumb down, etc.). However, this also is an example only, and should not be considered limiting. 
     As noted, a given pose may be executed in two or more different postures. Because of this, if the posture of an input can be determined as well as the pose, it is possible to associate different responses with each of several postures of a single pose. For example, considering free space hand postures as input for an electronic device such as a head-mounted display, a thumbs-up pose oriented in a thumb up posture, a thumb down posture, a thumb left posture, and a thumb right posture (as may be achieved by rotating the hand at the wrist) may invoke four different commands within that head-mounted display. 
     Such “repurposing” of a given pose may be useful in at least certain instances. For example, if a single pose may be used to input any of a group of commands that are in some fashion similar, administering input in such fashion may be relatively intuitive for the user. As a more concrete example, if basic navigation within an interface uses a single pose in different postures to input several different navigational commands, the user may find delivering such inputs intuitive (as opposed for example to using different poses). 
     However, it is emphasized that grouping pose/posture inputs in such fashion do not necessarily require that all such inputs be identical or even similar in behavior. For example, certain postures of a given pose may invoke a binary input such as “yes/no”, while other postures of that pose may invoke incremental inputs such as “move forward/move backward”. 
     Indeed, such an arrangement, while an example, may prove useful in basic navigation within an interface. Broadly speaking, when navigating through many (though not necessarily all) forms of content, “yes”, “no”, “go forward”, and “go back” may serve as “core” functions for navigation. While not all inputs are necessarily only to yes, no, forward, and back, those four inputs may provide a basic structure around which other inputs may be assembled. For example, if the capability for a numeric or alphanumeric input is desired, a “keypad” input may be added; likewise, if the capability for a “take picture” input is desired, such an input also may be added. However, the four core navigational commands-yes, no, forward, and back-nevertheless may remain both intuitive and/or memorable to the user, and consistent throughout various portions of the interface. 
     With reference now to  FIG. 2A  and  FIG. 2B , one example arrangement for implementing such core navigational functions with a single pose is shown. 
     In  FIG. 2A , a first input axis  220 A is shown, being substantially horizontal (i.e., extending left and right on the page). A second input axis  222 A also is shown, being substantially vertical (i.e., extending up and down on the page). Such axes may serve to help define postures using a single pose, for example by providing a frame of reference for the orientation of such a pose so as to manifest several different postures. 
     In  FIG. 2B , similar first and second input axes  220 B and  222 B are again shown. Four instances of a single pose  216 B also are shown. In addition, each pose  216 B exhibits a directionality, oriented in one of the two directions of the first and second input axes  220 B and  222 B. Thus, each of the four poses  216 B shown in  FIG. 2B  also represents a single posture  218 B- 1 ,  218 B- 2 ,  218 B- 3 , and  218 B- 4 . (For purposes of illustration, circles represent the pose  216 B, while the arrows in those instances of the pose  216 B identify directionality for the pose  216 B, thus distinguishing the four instances of the pose  216 B into four separate postures  218 B- 1 ,  218 B- 2 ,  218 B- 3 , and  218 B- 4 . Colloquially, posture  218 B- 1  may be considered to be the pose  216 B while “pointing right”, with posture  218 B- 2  being the pose  216 B while “pointing left”, posture  218 B- 3  being the pose  216 B while “pointing up”, and posture  218 B- 4  being the pose  216 B while “pointing down”. Precise definitions of what “pointing up” etc. entails may vary from one pose to another; for example, a first pose may be “pointing up” if the first is extended with the arm substantially vertical and the first at the top, but other poses and postures may be defined differently.) 
     Thus, as shown in  FIG. 2B , a single pose  216 B may exhibit four different postures  218 B- 1 ,  218 B- 2 ,  218 B- 3 , and  218 B- 4  based on the orientation of that pose  216 B along two axes  220 B and  222 B. Such an arrangement may be useful (as described in more detail below) but is an example only and arrangements may vary considerably. For example, though the axes  220 B and  222 B are shown in  FIG. 2B  as being vertical and horizontal, it is not required that two such axes be vertical and horizontal, or even perpendicular to one another. Moreover, arrangements with more than two axes, arrangements with axes that are not coplanar (for example with a third axis pointing in and out of the page), etc. may be equally suitable. Likewise, an arrangement with only one axis, for example  220 B, also may be suitable. 
     However, with two axes  220 B and  222 B as shown in  FIG. 2B , four postures  218 B- 1 ,  218 B- 2 ,  218 B- 3 , and  218 B- 4  all with the same pose may be conveniently defined. With four such postures  218 B- 1 ,  218 B- 2 ,  218 B- 3 , and  218 B- 4  the four core navigation functions mentioned previously—yes, no, forward, and back—may be associated with one function per posture. 
     As an example, posture  218 B- 1 —oriented right along the first axis  220 B—may be associated with a “forward” command, for example, scrolling forward through content (or scrolling the content itself) in some manner or otherwise positively progressing or incrementing some parameter. Posture  218 B- 2 —oriented left along the first axis  220 B (the opposite direction from posture  218 B- 1 )—may be associated with a “back” command, for example, scrolling backward through content (or scrolling the content itself) in some manner or otherwise negatively progressing or incrementing some parameter. Posture  218 B- 3 —orientated up along the second axis  222 B—may be associated with a “yes” or “affirmative” command, for example accepting some feature or otherwise indicating some binary logical state. Posture  218 B- 4 —orientated down along the second axis  222 B (the opposite direction from posture  218 - 3 )—may be associated with a “no” or “negative” command, for example, rejecting some feature or otherwise indicating some binary logical state (e.g. a logical state opposite that for posture  218 B- 3 ). Thus with such an arrangement shown in  FIG. 2B , four core navigation functions of forward, back, yes, and no may be implemented with a single pose, and four postures in four directions along two axes. 
     The arrangement shown in  FIG. 2B  may be useful in at least certain circumstances, for example potentially being intuitive to certain users. Consider an example arrangement wherein the pose is a first with an extended thumb. The notion of “thumbs up” as meaning “yes” is widespread as a colloquialism (though not necessarily universal); likewise the notion of “thumbs down” as meaning “no” also is widespread. Associating “yes” and “no” commands respectively with “thumbs up” and “thumbs down” postures of an extended thumb pose may be perceived as intuitive by at least certain users. Similarly, in certain cultures such as those using writing systems that are read “left to right”, the notion of equating “to the right” with “forward” and/or “to the left” with “backward” also may be perceived as intuitive. Thus, an extended thumb pose oriented to the right (i.e. with the thumb extending right) may be an intuitive posture input for “forward”, and an extended thumb pose oriented to the left may be an intuitive posture input for “backward”. 
     It is noted that “thumbs up” is not necessarily a universal affirmative. Certain cultures may associate different meanings, potentially meanings that may not be associated with navigation and/or meanings that are insulting or otherwise less than desirable. Thus, although the extended thumb pose is used herein as a concrete example in certain instances, it is emphasized that embodiments are not limited only to an extended thumb pose. Other poses, including but not limited to fists, flat hands, pointing index fingers, etc. also may be suitable. 
     However, regardless of the choice of pose, it may be advantageous to organize postures based thereon with regard to opposites, or at least related concepts. For example, with reference to  FIG. 2B  it may be possible to associate “yes” with upward posture  218 B- 3  while associating “no” with rightward posture  218 B- 1 . However, where “yes” and “no” typically are understood as opposites, “up” and “right” may not be so understood to be opposites. Thus, arranging opposites—for the four control inputs referenced, pairs “yes” and “no”, and “forward” and “backward” respectively—as being spatially opposite (or in some other fashion visibly and/or practically opposite) may be useful in providing intuitive inputs. Thus, while it may be suitable in certain instances to place “yes” and “no” along a horizontal axis such as  220 B rather than a vertical axis such as  222 B, typically it may not be desirable to arrange postures and inputs in a random or arbitrary fashion. In colloquial terms, poses and/or postures should “make sense”, and/or “mean something” to prospective users. Typically this may mean opposing “yes” with “no”, and/or “forward” with “backward”. 
     It is noted that the use of two different input types—“yes” and “no” in the one instance, and “forward” and “backward” in the other—also may be useful. “Yes” and “no” are essentially binary, that is, a state may be either “yes” or “no”, but typically not “maybe”, “six”, or “blue”. By contrast, “forward” and “backward” are progressive through a range, that is, one moves through content as though through pages in a book, through time in a video, through space in a virtual environment, etc. Such a pairing of two different input types may be useful in navigation. For example, while it may be possible to merely use core commands to move (as with “forward” and “backward”), without some way to accept or decline, or deliver at least basic secondary inputs, such input is not much more than passive panning, as opposed to true navigation wherein a user interacts with a system. Conversely, it may be possible to merely use core commands for binary or otherwise discrete inputs (A, B, C, or D), but without some way to select to what the user is saying “yes” or “no” to (from among what the user is selecting A, B, C, or D), such input again is extremely limited. 
     Thus, as a basic navigational core, at least one indicative option—potentially but not necessarily yes/no or otherwise binary—and at least one-dimensional option—potentially but not necessarily forward/back or otherwise progressive may be useful. Thus, four such inputs may be considered as a core navigational set. (Although this does not exclude the possibility, for example, that for certain instances, simple one-axis panning nonetheless may be sufficient for core input, or that other arrangements also may be suitable.) 
     It should be understood that the use or identification of certain inputs as “core inputs” does not in any way exclude the use of other inputs. The four core inputs as described may be sufficient to provide basic functionality, and/or also may be intuitive with proper selection and arrangement of pose and postures, but other inputs may be used as well. Examples may include but are not limited to other poses and postures for other functions, and the use of the same pose in other postures (e.g. along a third axis such as in a 2D hexagonal arrangement or a 3D Cartesian arrangement, considering rotation about other axes, etc.). 
     Now with reference to  FIG. 3A  and  FIG. 3B , therein is shown an example arrangement for control using multiple postures of a single pose. 
     In  FIG. 3A , a first control function is established  332 A. A control function is some event that causes a response to be carried out, such as an executable instruction instantiated on a processor that when executed carries out some form of a command. As a more concrete example, the first control function established  332 A may be a navigational command in a processor, that invokes a forward scroll through content (such as advancing through a document, advancing from one slide to the next, etc.) or some other forward progression. However, other arrangements may be suitable. 
     A second control function is established  332 B. For example, the second control function established  332 B may be a navigational command in a processor, that invokes a backward scroll through content (such as moving backward through a document, switching from one slide to the previous slide, etc.) or some other backward progression. However, other arrangements may be suitable. 
     Typically though not necessarily, the first and second control functions may be opposite one another, for example, processor commands for “forward” and “backward respectively. Also typically though not necessarily, the first and second control functions may be, or may be considered as, progressive. That is, the first and second control functions may move through some parameter, such as advancing or retreating through a series of pages or slides. The parameter and motion therethrough may vary considerably. For example, the parameter may be continuous, such as space or distance, with motion therethrough resembling continuous scrolling; however, the parameter also may be discrete, such as a page number or a slide number, so that motion therethrough is incremental (e.g. one page at a time). Other arrangements also may be suitable. 
     In addition, it is noted that although the parameter associated with the first and second control functions may be linear, it is not required that such a parameter be linear. For example, based on other inputs (such as “yes/no” inputs, described in more detail below), progression through content may branch or otherwise differ. Thus, if a “yes” input is registered for some binary logical consideration, executing a command to go forward with respect to a parameter may result in a different destination than if a “no” input had been registered followed by executing the command to go forward. Thus, the parameter(s) associated with the first and second control functions established  332 A and  332 B in  FIG. 3A  may be linear, but also may branch, include loops, etc. 
     Continuing in  FIG. 3A , a third control function is established  332 C. For example, the third control function established  332 C may be a first of two logical binary states, such as a “yes” or affirmative command that accepts some option. A fourth control function also is established  332 D, for example, a second of two logical binary states, such as a “no” or negative command that rejects some option. However, other arrangements may be suitable. 
     Again typically though not necessarily, the third and fourth control functions may be opposite one another, such as in the example given above wherein the third and fourth control functions represent “yes” and “no” respectively. Also typically though not necessarily, the third and fourth control functions may be, or may be considered as, selective rather than progressive. That is, the third and fourth control functions may represent selections, such as of logical states (yes/no, success/failure, understood/not understood, etc.). The particulars may vary considerably, however, and the examples given should not be considered as limiting. 
     Still with reference to  FIG. 3A , a first input axis is established  334 A. The first input axis represents some arrangement so as to define the possibility of at least two distinct inputs based at least in part on directionality with respect to that axis. For example, a horizontal spatial axis presents the possibility of options to the right or to the left (though other arrangements also may be suitable). A second input axis also is established  334 B. The second input axis also represents some arrangement so as to define the possibility of at least two distinct inputs based at least in part on directionality with respect to that axis. For example, a vertical spatial axis presents the possibility of options up or down (though again other arrangements may be equally suitable). 
     Typically though not necessarily, the first and second axes may be spatial and/or directional in nature. Likewise typically though not necessarily, the first and second axes may be perpendicular to one another, for example being horizontal and vertical axes. However, it is noted that axes need not be defined precisely or absolutely. For example, if first and second axes are to be established  334 A and  334 B so as to be vertical and horizontal, it is not required for the axes to be perfectly vertical and/or perfectly horizontal, or perfectly perpendicular, or defined with regard to any particular frame of reference. So long as the axes are sufficiently distinct as to be functionally different (e.g. in terms of aligning postures therewith), the definition may be sufficient. 
     It is noted that axes are not required to be strictly linear. For example, an axis may be curved, for example, so as to conform to human ranges of motion, etc. (e.g. curves defined by motions of various body joints). Stated differently, axes are not required to be strictly Cartesian and may be defined within spherical spaces, or even be arbitrarily curved or shaped to at least some degree, so long as those axes provide a clear distinction between orientations in one direction along such an axis and the opposite direction along that axis. 
     In addition, it is noted that defining “axes” is at least in part an illustrative notion, and is not necessarily limited to explicit axes. That is, defining quadrants of space, one extending to the right and one to the left, so as to define orientations to the left or the right, may be functionally equivalent to defining an axis. Definition of axes should be understood to encompass such variations. It is not necessarily required that a literal spatial axis is defined, so long as substantially opposing directionality is defined in some manner. While establishing  334 A and  334 B explicit axes is not prohibited, neither is establishing  334 A and  334 B explicit axes required. 
     Continuing in  FIG. 3A , a first input standard is established  336 A, associated with the first control function. That is, an event or events sufficient to be considered “input” for invoking the first control function are specified, i.e. defined as some standard. 
     The particulars of the first input standard (and likewise other input standards referenced below) may vary considerably. For example, the type of input may at least in part determine the form of the first input standard. As a more concrete example, if a hand posture is to serve as input, then the pose of the hand and the orientation of the hand may be part of the first input standard. Furthermore, even for such a posture, the first input standard may vary. For example, the posture may be defined geometrically and/or mathematically, such as in terms of the two-dimensional shape or outline of a hand, or in terms of the three-dimensional shape of the hand, or in terms of particular mathematical or dimensional relations (e.g. ratios of values such as finger length). 
     Input standards may be based on sensed data, derived data, stored data, etc., and are not limited with regard to the data source. For example, the first input standard for a pose and/or posture of a hand may consider the two-dimensional outline of the hand (e.g. directly sensed data such as by an imager), a three-dimensional wire skeleton of the hand (e.g. not necessarily directly sensed but at least potentially determined from sensed data, for example by computational techniques), a base model of anticipated hand parameters (e.g. predetermined based on typical human anatomy and stored for use), etc. 
     In addition, the type of data anticipated to be available regarding the input may affect the particulars of the first input standard. If data is obtained from an RGB camera image, for example, then features such as two-dimensional shape and/or color may be considered, but the three-dimensional shape may not be (as three-dimensional shape typically is not provided by a single RGB image). If data is obtained from a depth camera image, then a three-dimensional shape may be considered (e.g. based on depth data for the pixels in the image) but color data may not be considered (e.g. if the depth camera lacks color discrimination). If data is obtained from multiple sources, such as a pair of RGB imagers in a stereo configuration, an RGB imager in combination with a depth imager, etc., then the data of several different sorts may be considered. These are examples only, and other arrangements also may be suitable. 
     Typically though not necessarily, the first input standard may take the form of data and/or executable instructions instantiated on a processor. However, as noted the form may vary considerably, and thus the term “standard” should be understood broadly. The first input standard is not required to have any particular form but rather is defined functionally: that is, the first input standard is sufficient to determine whether a particular posture associated with a particular command has been executed. 
     Also typically though not necessarily, the first, second, third, and fourth input standards may be established  336 A,  336 B,  336 C, and  336 D so as to be exclusive of one another. That is, an input that satisfies the first input standard could not also satisfy any of the second, third, or fourth input standards. In other words, each input standard may be unique, such that a given input cannot readily be considered to satisfy two or more input standards. For example, considering a first input standard defining a “fist to the right” posture and a second input standard defining a “fist to the left” posture, the first and second input standards may be established  336 A and  336 B so that no anticipated posture reasonably would satisfy both the first and second input standards. More colloquially, the standards limit is an input to one or the other, but not both at once. 
     Still with reference to  FIG. 3A , a second input standard is established  336 B, associated with the second control function. An event or events sufficient to be considered “input” for invoking the second control function are specified. A third input standard is established  336 C associated with the third control function, and a fourth input standard is established  336 D associated with the fourth control function. Again, an event or events sufficient to be considered “input” for invoking the third and fourth control functions respectively are specified. 
     Typically though not necessarily, the first, second, third, and fourth input standards all may refer to various postures of a single pose. In such instance, the first, second, third, and fourth input standards may refer to postures at least substantially orientated with regard to first and second axes. For example, considering as a pose a “thumb extended” configuration of a hand, the first input standard may specify that pose in a rightward orientation (with the thumb pointing to the right, e.g. along a horizontal first axis), the second input standard may specify that pose in a leftward orientation, the third input standard may specify that pose in an upward orientation and the fourth input standard may specify that pose in a downward orientation. However, these are examples only, and other arrangements may be equally suitable. 
     With regard to the term “establish” (e.g. with respect to control functions, input axes, input standards, etc.), it is noted that to establish something may, depending on particulars, refer to either or both the creation of something new (e.g. establishing a business, wherein a new business is created) and the determination of a condition that already exists (e.g. establishing the whereabouts of a person, wherein the location of a person who is already present at that location is discovered, received from another source, etc.). 
     Similarly, “establishing” various entities as shown in  FIG. 3A  may encompass a range of events. For example, control functions, input axes, input standards, etc. may be created computationally (e.g. in a processor), may be read from stored data (e.g. instantiated onto a processor from a hard drive or solid state drive), may be received as communication from some external system, defined based on inputs, some combination thereof, etc. Unless otherwise specified, the manner by which various features may be established is not limited unless, nor is the actor (if any) that establishes those features limited. 
     Still with reference to  FIG. 3A , an input is then sensed  338 . The input may vary considerably. Typically though not necessarily, the input is a pose, such as a hand pose, exhibiting one of several postures. The input is not required to be one that meets any of the first, second, third, or fourth input standards established  336 A,  336 B,  336 C, and  336 D previously; other inputs may be sensed. The method as shown in  FIG. 3A  and  FIG. 3B  does not necessarily provide for action in response to such other inputs, but the existence of additional inputs, or even the sensing and execution of control functions or other actions in response thereto, also is not prohibited. 
     The manner by which the input is sensed is not limited. Typically though not necessarily, one or more sensors will provide data regarding an input. For example, a depth camera may capture an image or series of images, with the data in those images being analyzed to determine whether a hand is present, what pose the hand exhibits, what posture, etc. However, other arrangements also may be equally suitable. 
     Moving on to  FIG. 3B , a determination is made  340 A as to whether the input meets the first input standard. That is, does the input as sensed in  338  meet whatever criteria were set in establishing the first input standard  336 A? As a more concrete example, if the first input standard refers to a “thumb extended” pose oriented with the thumb to the right along a horizontal first axis, does the input, in fact, reflect a hand in a thumb extended pose with the thumb oriented to the right? 
     If the determination  340 A is positive—if the input does satisfy the first input standard—then the method continues with step  342 A. If the determination  340 A is negative—if the input does not satisfy the first input standard—then the method skips step  342 A and continues with step  340 B. 
     If the determination  340 A is positive, then the first control function is executed  342 A in response to the input. For example, if the first control function is to advance incrementally through some discrete form of content, then that content is then advanced one increment. More colloquially, a system subject to the first control function may move to the next slide, the next page, the next question, etc. 
     Moving on in  FIG. 3B , a determination is made  340 B as to whether the input meets the second input standard. If the determination  340 B is positive—if the input does satisfy the second input standard—then the method continues with step  342 B, wherein the second control function is executed. However, if the determination  340 B is negative—if the input does not satisfy the second input standard—the method skips step  342 B and continues with step  340 C. 
     Similarly, a determination is made  340 C as to whether the input meets the third input standard. If the determination  340 C is positive—if the input does satisfy the third input standard—then the method continues with step  342 C, wherein the third control function is executed. However, if the determination  340 C is negative—if the input does not satisfy the third input standard—the method skips step  342 C and continues with step  340 D. 
     Again, a determination is made  340 D as to whether the input meets the fourth input standard. If the determination  340 D is positive—if the input does satisfy the fourth input standard—then the method continues with step  342 D, wherein the fourth control function is executed. However, if the determination  340 D is negative—if the input does not satisfy the fourth input standard—the method skips step  342 D. 
     It is noted that the particular arrangement of determinations  340 A,  340 B,  340 C, and  340 D as shown in  FIG. 3B  is an example only, and other arrangements may be equally suitable. For example, a where  FIG. 3B  shows four binary determinations  340 A,  340 B,  340 C, and  340 D, it may be equally suitable to use a single determination, e.g. “does the input meet any of the first, second, third, or fourth input standards?” and then executing the appropriate first, second, third, or fourth control function. Other arrangements also may be equally suitable. 
     It is noted that the method as shown in  FIG. 3A  and  FIG. 3B  may complete without any of the first, second, third, and fourth control functions being executed, for example, if the input does not meet any of the first, second, third, and fourth input standards (or more trivially, if no input is received at all). Such an event is acceptable; input may be delivered to invoke other control functions than those shown in  FIG. 3A  and  FIG. 3B , the input may be incorrect or unrecognizable, or events addressed as a system as potential input, in fact, may not be and/or may not be intended to be input at all (e.g. being conversational hand motions, image artifacts, etc.). 
     However, in certain instances, it may be useful to simply assume that any input would be intended by a user to meet one of the first, second, third, or fourth input standards, and exclude the possibility of input not meeting any of the first, second, third, and fourth input standards. In such instance, selection may be made based on which of the first, second, third, and fourth input standards the input most closely resembles, even if none are fully satisfied. 
     In addition, as noted previously, in at least certain embodiments the first, second, third, and fourth input standards may be established  338 A,  338 B,  338 C, and  338 D so as to be unique, that is, so that input is not anticipated to satisfy more than one such. Thus, although logically it may be possible that more than one determination  340 A,  340 B,  340 C, and  340 D could be positive (and thus more than one control function could be executed  342 A,  342 B,  342 C, and  342 D), in practice for the arrangements shown and described herein any one input typically will satisfy (at most) one determination  340 A,  340 B,  340 C, and  340 D, so that only one such control function  342 A,  342 B,  342 C, and  342 D is executed in response thereto. However, other arrangements also may be suitable. 
     In particular, it is noted that control functions may be plural entities. That is, though (for example) the first control function is referred to herein in the singular, the first control function at least potentially could encompass two or more individual executable instructions, commands, etc., and the second, third, and/or fourth control functions likewise. 
     Although  FIG. 3B  shows the method therein as being complete after step  342 D for purposes of simplicity, in practice a method may repeat, for example returning to step  338  in a loop so as to sense input in an ongoing fashion. A method also may proceed on to additional steps, may otherwise be more complex, etc. 
     Now with reference to  FIG. 4A  through  FIG. 4D , therein are shown four example postures as may serve as inputs for controlling a system, and as may satisfy first, second, third, and fourth input standards respectively and/or invoke first, second, third, and fourth control functions respectively for an arrangement similar to that shown in  FIG. 3A  and  FIG. 3B . Although  FIG. 4A  through  FIG. 4D  and certain other figures herein depict a thumb-extended pose in various postures, it is emphasized that both the particular pose and the particular postures thereof as illustrated are examples only, and that embodiments are not limited only thereto. 
     In  FIG. 4A , a hand  402 A is shown. As may be seen, the thumb  404 A is substantially extended, and the other four digits  406 A,  408 A,  410 A, and  412 A are substantially curled towards the palm and held substantially together. The configuration of the hand  402 A with respect to itself—thumb  404 A extended, other digits  406 A,  408 A,  410 A, and  412 A curled—is considered for purposes of discussion herein to be a pose, as described previously. That is, a pose does not consider the orientation of the hand (or another object under consideration) with regard to an external frame of reference, merely the configuration of the hand itself. 
     However, as also may be seen in  FIG. 4A , the hand  402 A is oriented in space such that the extended thumb  404 A points substantially toward the right. Such orientation of the pose of the hand  402 A is considered for purposes of discussion herein to be a posture, as also described previously. “Thumb extended” is the pose shown in  FIG. 4A ; “thumb right” is the posture of that pose as shown in  FIG. 4A . 
     For purposes of example, the hand pose in the posture shown in  FIG. 4A  is presented as a first of four inputs (the rest shown in  FIG. 4B ,  FIG. 4C , and  FIG. 4D ) for navigating within a system. That first input as shown in  FIG. 4A  may be constrained to a first input standard that specifies the pose and posture to at least approximately that shown. That input standard itself may reference a horizontal first axis (not shown in  FIG. 4A ), such that the thumb  404 A aligns substantially along that first axis in one direction (i.e. to the right). In addition, a first control function may be associated with the pose and posture as shown in  FIG. 4A , such that sensing the pose and posture as shown in  FIG. 4A  invokes the first control function. Again as an example, that first control function may be a forward progression, such as moving from one slide to the next. 
     Turning to  FIG. 4B , again a hand  402 B is shown. The thumb  404 B is substantially extended, and the other four digits  406 B,  408 B,  410 B, and  412 B are substantially curled towards the palm and held substantially together. Thus the pose of the hand  402 B shown in  FIG. 4B  is at least substantially the same as the pose of the hand  402 A shown in  FIG. 4A . However, as also may be seen in  FIG. 4B , the hand  402 B is oriented with the extended thumb  404 B pointing substantially toward the left. Thus, although the poses of hands  402 A and  402 B may be similar or identical, the postures exhibited by hands  402 A and  402 B are different (and in at least a directional sense, opposites). 
     For purposes of example, the posture in  FIG. 4B  is presented as a second input for navigating within a system. That second input may be constrained to a second input standard that specifies the pose and posture, and that second input standard may reference a horizontal first axis such that the thumb  404 B aligns substantially along that first axis in a second direction (i.e. to the left) substantially opposite that of the thumb  404 A in  FIG. 4A . A second control function may be associated with the posture in  FIG. 4B , such that sensing the posture in  FIG. 4B  invokes the second control function. The second control function may be a backward progression, such as moving from one slide to the previous. 
     Now with reference to  FIG. 4C , a hand  402 C is shown. The thumb  404 C is substantially extended, and the other four digits  406 C,  408 C,  410 C, and  412 C are substantially curled towards the palm and held substantially together. Thus the pose of the hand  402 C shown in  FIG. 4C  is at least substantially the same as the pose of the hands  402 A and  402 B shown in  FIG. 4A  and  FIG. 4B . However, in  FIG. 4C  the hand  402 C is oriented with the extended thumb  404 C pointing substantially upward. Although the poses of hand  402 C may be similar or identical to the poses of hands  402 A and  402 B, the posture exhibited by hand  402 C is different from those exhibited by  402 A and  402 B. 
     For purposes of example, the posture in  FIG. 4C  is presented as a third input for navigating within a system. That third input may be constrained to a third input standard that specifies the pose and posture, and that third input standard may reference a vertical axis (not shown in  FIG. 4C ) such that the thumb  404 C aligns substantially along that second axis in a first direction (i.e. up). A third control function may be associated with the posture in  FIG. 4C , such that sensing the posture in  FIG. 4C  invokes the third control function. The third control function may be a first binary state, such as “yes”. 
     Turning to  FIG. 4D , a hand  402 D is shown. The thumb  404 D is substantially extended, and the other four digits  406 D,  408 D,  410 D, and  412 D are substantially curled towards the palm and held substantially together. Thus the pose of the hand  402 D shown in  FIG. 4D  is at least substantially the same as the pose of the hands  402 A,  402 B, and  402 C shown in  FIG. 4A ,  FIG. 4B , and  FIG. 4C  respectively. However, in  FIG. 4D  the hand  402 D is oriented with the extended thumb  404 D pointing substantially downward. Although the poses of the hand  402 D may be similar or identical to the poses of hands  402 A,  402 B, and  402 C, the posture exhibited by hand  402 D is different from those exhibited by  402 A,  402 B, and  402 C (and in at least a direction sense, opposite to the posture of hand  402 C). 
     For purposes of example, the posture in  FIG. 4D  is presented as a fourth input for navigating within a system. That fourth input may be constrained to a fourth input standard that specifies the pose and posture, and that fourth input standard may reference a vertical axis such that the thumb  404 D aligns substantially along that second axis in a second direction (i.e. down) substantially opposite that of the thumb  40 CA in  FIG. 4C . A fourth control function may be associated with the posture in  FIG. 4D , such that sensing the posture in  FIG. 4D  invokes the fourth control function. The fourth control function may be a second binary state opposed to the first binary state associated with the posture of  FIG. 4C , such as “no”. 
     As may be seen, collectively the poses exhibited by the four hands  402 A,  402 B,  402 C, and  402 D are all identical or at least substantially similar, even though the postures of those four hands  402 A,  402 B,  402 C, and  402 D are visibly different, being oriented right, left, up, and down respectively. Colloquially, it might be said that a user making such postures is “doing the same thing, in different directions”. In effect, the user would be required to remember only a single pose, using that pose for postures oriented in several directions; such an arrangement may be simple and/or intuitive, particularly if (as in the example shown) the postures themselves are evocative of the control functions to be delivered: thumb right and thumb left for forward and back, and thumb up and thumb down for yes and no. 
     As noted previously, those four functions—forward, back, yes, and no—may serve as at least the functional core of navigation for controlling a system. Thus four postures, using a single pose, oriented along two axes, may provide sufficient basic functionality as to control a device (e.g. a portable electronic device, a wearable device such as a head mounted display, a home game console, etc.). As may be understood, the particulars of such an arrangement are not necessarily arbitrary. 
     Use of a single for such core navigational functions pose may simplify recognition protocols (e.g. making machine vision or other sensing tasks more manageable), and/or may be easy to remember for a user. Such an arrangement-one single pose, used for several clearly designated functions—might be described as “unity of control”. 
     Use of linear axes may facilitate opposition of functions. That is, for “yes/no” binary inputs, using opposite directions for opposite meanings—up and down, for yes and no respectively—may be intuitive to users. Such opposition also may enable more convenient discrimination of one input from another. Although machine vision and other sensing techniques may be subject to a variety of challenges, discriminating “up” from “down” may be a relatively straightforward matter (as opposed for example to detecting and identifying more subtle differences). 
     Use of multiple axes enables a greater number of inputs (e.g. four with two oppositional axes, vs. two with a single axis). Use of clearly distinct axes may again facilitate easy memorization of inputs for users, since “up, down, right, and left” are conceptually simple. Clearly, distinct axes also may ease challenges in detecting and discriminating different inputs, as noted above with regard to linear axes. 
     Furthermore, associating two different functions with two different axes may be useful in at least certain embodiments. A combination of a selection input and a motion input together may support at least basic navigation. In the example shown and described with regard to  FIG. 4A  through  FIG. 4D , that selection input is yes/no, while the motion input is forward/back. Selection alone or motion alone provides only very limited navigation, as noted previously. However, given at least one selection option with at least two choices and at least one motion option with at least two choices, a much richer, more capable interface may be provided. One way of achieving such clarity is to use axes that are perpendicular to one another, though other arrangements also may be suitable. 
     It is, of course, possible to support additional choices for selection (e.g. A through D rather than yes/no) and/or for motion (forward/back/up/down), and/or to provide additional selection functions, motion functions, and or other functions. In practice, such additional functionality may be useful and is not excluded from use with the core navigation arrangements shown and described herein. However, two observations may be illuminating in this matter. 
     First, as a general principle of design, it is in some ways ideal to make a system “as simple as possible (but no simpler)”. Thus, defining as core navigation functionality a minimum set of inputs and control functions that enables effective navigation—in the example of  FIG. 4A  through  FIG. 4D , yes/no and forward/back—may be useful both for users of an interface and designers who anticipate that interface being used. 
     Second, while it may be useful to have a large number of possible commands in a system, and/or for those commands to exhibit considerable variety, it is generally preferable that the necessary core functions—which in an interface may include basic navigation—be few in number. In part, this is for user convenience; a user may readily remember a handful of commands (particularly if those commands are similar and/or intuitive, e.g. through thumb pointing as in  FIG. 4A  through  FIG. 4D ), but remembering many dozens of commands may be problematic. It may be acceptable for a user to recall only some subset of a large number of optional commands, such as those he or she uses regularly, but it may not be prudent to expect users to remember a large number of commands that are necessary for system control. In addition, if core commands proliferate excessively, then those commands themselves may become indefinite. That is, if there are multiple commands to address a single function such as “indicate yes or no”, then the definition and behavior of different varieties of indicating yes or no may be different (even if in subtle ways). 
     Thus, the particulars of the example shown and described with regard to  FIG. 4A  through  FIG. 4D —unity of control with a single posture for core navigation inputs, a small number of core inputs with a variety of functions (e.g. selection and motion), clear oppositional and axial definitions for inputs, and choice of intuitive inputs—may be advantageous as noted above (and for other reasons not necessarily specified herein). 
     However, the arrangement in  FIG. 4A  through  FIG. 4D  is an example only, and other arrangements may be equally suitable. 
     Now with reference to  FIG. 5A  through  FIG. 5D , therein four postures of a thumb-extended pose are again shown. The pose and postures are at least somewhat similar to  FIG. 4A  through  FIG. 4D , but are shown end-on in  FIG. 5A  through  FIG. 5D  for clarity (and as a baseline for the description of degeneracy with regard to  FIG. 6A  through  FIG. 6D , below). 
     In  FIG. 5A , as may be seen a hand  502 A is shown therein with a pose such that the thumb  504 A is extended and the fingers  506 A through  512 A are curled towards the palm. Such a pose may be referred to as a thumb-out or thumb-extended pose. (Colloquially, a pose as shown in  FIG. 5A  is sometimes referred to as “thumb-up”, but when oriented with the thumb right as in  FIG. 5A  such description may be unclear.) The hand  502 A is oriented so as to exhibit a thumb-right posture, with the thumb aligned horizontally and extending to the right as seen. 
     In  FIG. 5B , a hand  502 B is shown in a pose with thumb  504 B extended and fingers  506 B through  512 B curled towards the palm. The hand  502 B is oriented in a thumb-left posture, with the thumb aligned horizontally and extending to the left. 
     In  FIG. 5C , a hand  502 C is shown in a pose with thumb  504 C extended and fingers  506 C through  512 C curled towards the palm. The hand  502 C is oriented in a thumb-up posture, with the thumb aligned vertically and extending up. 
     In  FIG. 5D , a hand  502 D is shown in a pose with thumb  504 D extended and fingers  506 D through  512 D curled towards the palm. The hand  502 D is oriented in a thumb-down posture, with the thumb aligned vertically and extending down. 
     Taken together, the hands  502 A,  502 B,  502 C, and  502 D may be taken to represent four inputs similar to those described with regard to  FIG. 4A  through  FIG. 4D . Notably, as may be seen in  FIG. 5A  through  FIG. 5D  the alignment of each pose may be seen to be precise, in that the thumbs  504 A,  504 B,  504 C, and  504 D are oriented directly right, left, up, and down respectively. In some sense the precision of orientation of the poses in  FIG. 5A  through  FIG. 5D  may be considered to represent an ideal: for example, the “thumb-up” in  FIG. 5C  is directly up, rather than being noticeably offset. 
     However, with reference to  FIG. 6A  through  FIG. 6D , it is not required that such precision exist, or that postures be defined so as to specify precise orientation. 
     In  FIG. 6A , a directional arrow  650 A is shown, pointing upward. For purposes of discussion, the directional arrow  650 A represents the two-dimensional orientation of a posture. For example, considering a thumb-extended pose, the upward orientation of the directional arrow  650 A may indicate that the hand is oriented with the extended thumb pointing upward (i.e. in the direction of the arrow shown in  FIG. 6A ). 
       FIG. 6A  also shows four arc sections  652 A- 1 ,  652 A- 2 ,  652 A- 3 , and  652 A- 4 . Each arc section  652 A- 1 ,  652 A- 2 ,  652 A- 3 , and  652 A- 4  is shown to encompass 90 degrees of arc, in directions corresponding with right, left, up, and down respectively.  FIG. 6A  illustrates one possible arrangement for addressing possible degeneracy in the orientation of postures. Namely, rather than requiring perfect alignment to the left, the right, up, or down, so long as a suitable pose falls within 90-degree arcs  652 A- 1 ,  652 A- 2 ,  652 A- 3 , and  652 A- 4  that pose will be accepted as a posture oriented left, right, up, or down respectively. 
       FIG. 6A  thus represents tolerance of a high level of degeneracy. A posture may be considered as “degenerate” if the posture deviates in some manner from the ideal for that posture, typically though not necessarily in terms of orientation in space. In practice, some level of degeneracy may be expected in real-world posture inputs. To some degree, this may represent “sloppiness” in executing postures, but postures also may be executed differently by different users. For example, some users may perceive “vertically up” slightly differently than other users. Thus postures tend to be at least somewhat unique; an analogy might be that many writers may tend to incline their letters to some degree or other, rather than writing the letters so as to be perfectly vertical. In addition, sensors and processing techniques may introduce apparent error in the orientation of sensed postures, even if a user executes those postures perfectly. 
     Thus, some degree of tolerance for degeneracy in postures may be desirable in at least certain embodiments. The arrangement shown in  FIG. 6A , wherein the degree of allowed degeneracy is up to plus-or-minus 45 degrees, may be suitable in certain instances. 
     However, in other instances, it may be useful to limit the allowable degeneracy to at least some degree. With reference to  FIG. 6B , a directional arrow  650 B again is shown, as an example orientation of a posture.  FIG. 6B  also shows arc sections  652 B- 1 ,  652 B- 2 ,  652 B- 3 , and  652 B- 4 , each encompassing approximately 88 degrees of arc in directions corresponding with right, left, up, and down respectively.  FIG. 6B  shows four additional arc sections  654 B- 1 ,  654 B- 2 ,  654 B- 3 , and  654 B- 4 , each encompassing approximately 2 degrees of arc in between adjacent arc sections  652 B- 1 ,  652 B- 2 ,  652 B- 3 , and  652 B- 4 . The 88-degree arc sections  652 B- 1 ,  652 B- 2 ,  652 B- 3 , and  652 B- 4  represent orientations that may be accepted as right, left, up, and down oriented postures; the 2-degree arc sections  654 B- 1 ,  654 B- 2 ,  654 B- 3 , and  654 B- 4  represent orientations that may be rejected as not being acceptable posture orientations. 
     The arrangement in  FIG. 6B  exhibits relatively large ranges of acceptable orientations (i.e. 88 degrees for each of the four orientations therein), as does the arrangement in  FIG. 6A . However in  FIG. 6B  the 2 degree “dead zones” serve as buffers. Where in  FIG. 6A , a posture oriented 45 degrees off of vertical or horizontal might satisfy two adjacent orientations of posture, e.g. right and up, at the same time. Alternately, a sensor or processing technique may “stutter” between identifying a pose at a 45-degree angle as an “up” posture and a “right” posture, shifting back and forth rapidly between two different determinations. Either case for  FIG. 6A  may present problems, while the arrangement in  FIG. 6B  may avoid such problems. 
     Turning to  FIG. 6C , a directional arrow  650 C is shown.  FIG. 6C  shows arc sections  652 C- 1 ,  652 C- 2 ,  652 C- 3 , and  652 C- 4 , each encompassing approximately 60 degrees of arc in directions corresponding with right, left, up, and down respectively.  FIG. 6C  also shows arc sections  654 C- 1 ,  654 C- 2 ,  654 C- 3 , and  654 C- 4 , each encompassing approximately 30 degrees of arc, in between adjacent arc sections  652 C- 1 ,  652 C- 2 ,  652 C- 3 , and  652 C- 4 . The 60-degree arc sections  652 C- 1 ,  652 C- 2 ,  652 C- 3 , and  652 C- 4  represent orientations that may be accepted as right, left, up, and down oriented postures; the 30-degree arc sections  654 C- 1 ,  654 C- 2 ,  654 C- 3 , and  654 C- 4  represent orientations that may be rejected as not being acceptable posture orientations. 
     The arrangement in  FIG. 6C  exhibits moderately large ranges of acceptable orientations (60 degrees for each of the four orientations therein) but also exhibits moderately large “dead zones” (30 degrees each) as well. Such an arrangement tolerates degeneracy in posture but also has significant “dead” arcs distinguishing and separating the acceptable orientations. Such an arrangement may be useful if, for example, determining orientation to within a few degrees is either impossible or for some reason undesirable, for example, due to limitations in hardware, processing power etc. 
     Similarly,  FIG. 6D  shows a directional arrow  650 D, along with arc sections  652 D- 1 ,  652 D- 2 ,  652 D- 3 , and  652 D- 4 , each encompassing approximately 15 degrees of arc in directions corresponding with right, left, up, and down respectively.  FIG. 6D  also shows arc sections  654 D- 1 ,  654 D- 2 ,  654 D- 3 , and  654 D- 4 , each encompassing approximately 75 degrees of arc, in between adjacent arc sections  652 D- 1 ,  652 D- 2 ,  652 D- 3 , and  652 D- 4 . The 15-degree arc sections  652 D- 1 ,  652 D- 2 ,  652 D- 3 , and  652 D- 4  represent orientations that may be accepted as right, left, up, and down oriented postures; the 75-degree arc sections  654 D- 1 ,  654 D- 2 ,  654 D- 3 , and  654 D- 4  represent orientations that may be rejected as not being acceptable posture orientations. 
     The arrangement in  FIG. 6D  exhibits relatively small ranges of acceptable orientations (15 degrees for each of the four orientations), with relatively large “dead zones” (75 degrees each). Such an arrangement tolerates only a limited degree of degeneracy in posture but still does not require perfect precision in postures being delivered as inputs. 
     The arrangements shown in  FIG. 6A  through  FIG. 6D  illustrate certain examples of degrees of degeneracy as may be acceptable in various conditions. Thus with regard to postures being oriented substantially upward, substantially to the right, substantially along an axis, etc., it should be understood that the degree of precision may vary considerably from one embodiment to another. While absolute precision may not be required, neither is any particular range of variation necessarily required or prohibited. So long as a determination may be made successfully regarding whether given postures are indeed oriented right, left, up, down, etc., the degree of precision is not limited. In addition, it is emphasized that the arrangements in  FIG. 6A  through  FIG. 6D  are examples only, and other arrangements may be equally suitable. 
     Turning now to  FIG. 7A  through  FIG. 7E , tolerance for at least some degree of degeneracy in poses also may be suitable. That is, not only the hand orientation (with respect to postures) but also the hand configuration (e.g. where the digits are in relation to one another, whether the digits are curled or extended, etc.) may be subject to some degree of degeneracy, and varying degrees of degeneracy may be accepted or rejected in various embodiments. 
     With reference specifically to  FIG. 7A , therein is shown a hand  702 A. As may be seen, the thumb  704 A is substantially extended, and the fingers  706 A,  708 A,  710 A, and  712 A are curled. Broadly speaking, the hand  702 A may appear to be in a thumb extended pose (and a thumb up posture, though variations in orientation are not discussed with regard to  FIG. 7A  through  FIG. 7D ). However, as may be seen from a comparison of  FIG. 7A  with  FIG. 4C , in  FIG. 7A  the fingers  706 A,  708 A,  710 A, and  712 A are not curled as tightly as in  FIG. 4C . More colloquially, the pose in  FIG. 7A  might be described as more “loose” than that in  FIG. 4C . 
     In  FIG. 7B  a hand  702 B is shown with the thumb  704 B substantially extended and the fingers  706 B,  708 B,  710 B, and  712 B slightly curled. It may be noted that the thumb  704 B in  FIG. 7B  also is less vertical than (for example) in  FIG. 7A , being disposed slightly more forward. In  FIG. 7C  a hand  702 C is shown with the thumb  704 C substantially extended and the fingers  706 C,  708 C,  710 C, and  712 C also extended. In  FIG. 7D  a hand  702 D is shown with the thumb  704 D substantially extended and the fingers  706 D,  708 D,  710 D, and  712 D extended and slightly spread. In  FIG. 7E  a hand  702 E is shown with the thumb  704 E only partially extended (exhibiting a straight appearance but being inclined forward and to the left), while the fingers  706 E,  708 E,  710 E, and  712 E are curled. 
     As with degeneracy in posture (previously described), degeneracy in pose may manifest for a variety of reasons, such as user error, variations in user preferences (e.g. what a given user considers to be “the right way to make a thumbs up”), variations in user anatomy, artifacts from sensors and/or processing techniques, etc. As with posture degeneracy, it may be useful to allow for some degree of pose degeneracy, though the exact degree is not limited and may vary from one embodiment to another. 
     Thus, the arrangements in  FIG. 7A  through  FIG. 7D  may be considered to exhibit various degrees and/or types of degeneracy, e.g. primarily with regard to the configuration of the fingers of hands  702 A,  702 B,  702 C,  702 D, and  702 E therein. The degree to which degeneracy is acceptable—which in some sense may be the degree to which a hand is “substantially” exhibiting a particular ideal pose—may vary considerably. In some embodiments, little or no degeneracy may be tolerated, such that none of hands  702 A,  702 B,  702 C,  702 D, and  702 E would be considered to be exhibiting a thumb-extended pose. In other embodiments, some degree of finger curl may be required, such that hands  702 A,  702 B, and  702 E may be considered as exhibiting a thumb-extended pose, but hands  702 C and  702 D would not be (being too degenerate). In yet other embodiments, even hand  702 C, with fingers fully extended, and/or hand  702 D, with fingers not only extended but also spread, may be considered as exhibiting a thumb-extended pose. In still other embodiments, insufficient or absent finger curl in hands  702 A,  702 B,  702 C, and  702 D may result in those hands not being accepted as thumb-extended poses, even if significant inclination of the thumb as in hand  702 E (or other properties such as lack of extension of the thumb, etc.) is still accepted as a thumb-extended pose. 
     The particulars regarding acceptable pose degeneracy, like the particulars of how a pose is defined in the first place, may vary considerably. As an extreme case, a pose may be required to be highly precise, exhibiting little or even no detectable degeneracy from some ideal standard. Such an arrangement may facilitate discrimination between poses and non-inputs (e.g. by ignoring anything that is not a highly precise pose). 
     However, an input standard for a posture including a thumb-extended pose also may tolerate a high degree of degeneracy. As a different extreme case an input standard may be established such that so long as the thumb is distinguishable as being separate from the remainder of the hand, the thumb extended-pose is being exhibited. In such case, whether the fingers are curled or extended, together or spread, the degree to which the thumb is extended or upright, etc. may be ignored so long as the thumb itself is distinct from the rest of the hand. Such an arrangement may facilitate ease of user interaction (e.g. by allowing for “casual” use without requiring a user to pay attention to making highly precise inputs). 
     Depending on circumstances, different ranges of degeneracy, different factors of degeneracy (e.g. finger curl, finger spread, thumb extension, thumb alignment, etc.), and other variations may be suitable. The preceding are examples only, and should not be considered limiting. 
     Now with regard to  FIG. 8A  and  FIG. 8B , thus far certain examples of poses and postures shown thus far have been relatively simple. For example, certain poses have been described addressing mainly the curl/extension and alignment of digits, while certain postures have been described addressing only orientation within a plane (e.g. right, left, up, down). However, other factors may be considered in defining postures and/or poses. 
     For example, referring to  FIG. 8A  orientation other than that of a primary indicator may be considered. That is, for certain previous examples regarding postures based on a thumb extended pose, only the direction in which the thumb points may have been considered. However, hands (and other input sources) may not be limited only to such simple orientations, and thus other factors may be considered regarding postures. 
     As seen in  FIG. 8A , a hand  802 A is shown, with the thumb  804 A extended and the fingers  806 A,  808 A,  810 A, and  812 A curled. Thus the hand  802 A may reasonably be considered to be a thumb-extended pose. In addition, as may be seen, the thumb  804 A is oriented upward, so by at least some definitions the hand  802 A may be considered to be a thumb-up posture. However, as may be seen the arrangement in  FIG. 8A  differs from certain previous examples of thumb-up postures, such as shown in  FIG. 4C . In  FIG. 4C , the hand is viewed from behind and somewhat to the left, as may be anticipated if the hand was viewed from a perspective corresponding with the head of a user if the hand was extended in front of the user. By contrast, in  FIG. 8A  the hand is viewed from the palm side. An arrangement such as in  FIG. 8A  may be anticipated if the hand was held in front of a head-mounted sensor, extending in from the right (e.g. with the elbow bent). 
     Depending on the embodiment, it may be suitable to simply consider an arrangement such as shown in  FIG. 8A  as a thumb-up posture, functionally equivalent to that in  FIG. 4C . That is, the only orientation factor considered would be where the thumb points. However, it also may suitable in other embodiments to consider factors of hand orientation other than only the direction of the thumb. Thus, depending on the embodiment, the hand  804 A in  FIG. 8A  may be considered to be a thumb-up posture equivalent to that in  FIG. 4C  or the hand  804 A may be considered to be a different posture (given that the hand is arranged with fingers generally to the left in  FIG. 8A , as opposed to generally forward in  FIG. 4C ). 
     Alternately, the arrangement shown in  FIG. 8A  may for certain embodiments be considered as a form of degeneracy, i.e. in that the arm is not in an ideal anticipated position/orientation for a given pose and/or posture. Classifying the arrangement of  FIG. 8A  as degeneracy, and variations in the degree of such degeneracy accepted, may be suitable for certain embodiments. 
     Consequently, the arrangement in  FIG. 8A  may or may not be considered as a thumb-up posture, and/or may or may not be considered as a distinctly different posture (potentially invoking different control functions). Either option is acceptable for certain embodiments, and other arrangements also may be suitable. 
     Turning to  FIG. 8B , another option is also presented with regard to pose and/or posture. As may be seen, a hand  802 B is shown, with the thumb  804 B extended and the fingers  806 B,  808 B,  810 B, and  812 B curled. Thus the hand  802 B again may reasonably be considered to be a thumb-extended pose. The thumb  804 B is oriented upward, so by at least some definitions the hand  802 B also may be considered to be a thumb-up posture. However, the arrangement in  FIG. 8A  differs from certain previous examples of thumb-up postures in that a wrist  814 B is shown to be bent, turning the hand  802 B to the left. 
     Again, it may be suitable to simply consider  FIG. 8B  to show a thumb-up posture, functionally equivalent to that in  FIG. 4C . However, it also may be suitable to consider the bend in the wrist  814 B with regard to pose and/or posture. For example, the hand  80 BA in  FIG. 8B  may be considered to be a thumb-up posture equivalent to that in  FIG. 4C  or the hand  804 B may be considered to be a different posture (given that the hand is arranged with fingers generally to the left in  FIG. 8A , as opposed to generally forward in  FIG. 4C ). The hand  804 B may even be considered to be a different pose if the wrist is considered to be part of the hand (which may be permitted but is not required). 
     Alternately, the arrangement shown in  FIG. 8B  may be considered a form of degeneracy. Classifying the arrangement of  FIG. 8B  as degeneracy, and variations in the degree of such degeneracy accepted, may be suitable for certain embodiments. 
     Thus the arrangement in  FIG. 8B  also may or may not be considered as a thumb-up posture, and/or may or may not be considered as a distinctly different posture (potentially invoking different control functions). Either option is acceptable for certain embodiments, and other arrangements also may be suitable. 
     Broadly speaking, the arrangements in  FIG. 8A  and  FIG. 8B  may be considered to represent additional degrees of freedom. That is, in addition to finger and thumb configuration and thumb orientation, overall hand orientation, wrist position, etc. may be considered with regard to poses and/or postures. Other degrees of freedom besides those specifically shown and described also may be considered. While such additional considerations are not required, neither are they prohibited, and the degrees of freedom to be considered for poses and/or postures is not limited unless otherwise specified. 
     In addition, it should be understood that what is considered to be a pose and a posture may vary. For example, if the hand is considered not to include the wrist, then bending the wrist may be considered to affect posture (by changing the orientation of the hand) but not pose (since bending the wrist does not define how the digits are disposed). However, if the wrist is also considered to be part of the hand, then bending the wrist may represent part of the pose. Similarly, in it may be possible to consider an arm with a forearm, elbow, etc., with the configuration of the entire arm and hand defining the pose. In principle, it may even be possible to define pose with regard to an entire body, with posture then relating to the orientation and/or position of that body in space. In practice, it may prove convenient to consider only the hand, potentially but not necessarily including the wrist, as the “actor” for defining poses. However, such a definition is to some degree arbitrary, and other arrangements also may be suitable. 
     Now with regard to  FIG. 9A  and  FIG. 9B , it is noted that while a wide variety of poses and/or postures may be considered, it is not required that all theoretically possible poses or postures be considered. Certain inputs may be excluded, based for example on concerns such as anatomical improbability. 
     In  FIG. 9A , a hand  902 A is shown with the thumb  904 A extended and the fingers  906 A,  908 A,  910 A, and  912 A curled. Thus by a strict definition, the hand  902 A could be considered to be a thumb-extended pose. The thumb  904 A is oriented upward, so by at least some definitions the hand  902 A also could be considered to be a thumb-up posture. 
     Also, in  FIG. 9B  a hand  902 B is shown with the thumb  904 B extended and the fingers  906 B,  908 B,  910 B, and  912 B curled. Again by a strict definition, the hand  902 B could be considered to be a thumb-extended pose. The thumb  904 B is oriented upward, so again by at least some definitions the hand  902 B also could be considered to be a thumb-up posture. 
     However, the orientation of the hands  902 A and  902 B with regard to the point of view is noted. Namely, the hand  902 A is viewed from the back, while the hand  902 B is viewed knuckles-on. For certain arrangements, such as a sensor disposed on a user&#39;s head (e.g. on a head mounted display), it may be concluded that the hands  902 A and/or  902 B may be unlikely to belong to the user. Consider the possibilities of arranging one&#39;s own right hand with the thumb up but the with the back of the hand facing one&#39;s eyes, or with the thumb up but with the knuckles facing one&#39;s own eyes. Such arrangements are, if perhaps not entirely impossible for human anatomy, then at least extremely difficult. It may be more likely that such arrangements would indicate that the hands  902 A and/or  902 B belong to some other person, e.g. the hand of a person facing the user, rather than the hand of a person wearing the sensor itself. Thus, for at least certain embodiments it may be suitable to exclude hands such as  902 A and  902 B as input; even though technically the hands  902 A and  902 B may represent a thumb-extended pose in a thumb-up posture. 
     Other factors besides hand orientation also may be considered in excluding potential input. For example, factors regarding the user (e.g. known hand coloration, hand proportions, a history of making poses/postures in a certain manner, etc.) and/or other factors also may be considered in excluding certain data as inputs, even if that data otherwise conforms to general definitions for suitable poses and/or postures. However, such exclusions, while permissible, are not required. 
     Now with reference to  FIG. 10A  through  FIG. 100 , as has been noted, the use of a thumb-extended pose is presented as an example only, and other poses may be equally suitable.  FIG. 10A  through  FIG. 100  show three additional examples, as may be suitable for other embodiments. These examples should not be considered to be either exhaustive or limiting; other arrangements may be equally suitable. However, it is noted that the three examples shown all may be suitable for use in the “four posture” arrangement of input, wherein a single pose may serve to invoke yes, no, forward, and back control functions (or comparable functions) depending whether that pose manifests as right, left, up, and down postures respectively. That is, finger pointing (as in  FIG. 10 ), flat hand pointing (as in  FIG. 10B ), and/or first pointing (as in  FIG. 100 ) may serve for the four-posture arrangement of core system navigation already described herein. 
     Specifically with regard to  FIG. 10A , a hand A is shown with the index finger A extended, the other fingers A, A, and A curled, and the thumb A held alongside the hand A (colloquially a “pointing finger”). Considering the arrangement in  FIG. 10A  to be a pose, such a pose may be oriented for example in postures pointing right, left, up, and down, so as to support four-posture core navigation. 
     In  FIG. 10B  a hand B is shown with the fingers B, B,  8 , and B extended, and the thumb A held alongside the hand B (colloquially an “open hand”). Considering the arrangement in  FIG. 10B  to be a pose, such a pose also may be oriented for example in postures pointing right, left, up, and down, so as to support four-posture core navigation. 
     In  FIG. 100 , a hand C is shown with the index fingers C, C, C, and C curled and the thumb C held alongside the hand C (colloquially a “fist”.) Considering the arrangement in  FIG. 100  to be a pose, such a pose again may be oriented for example in postures pointing right, left, up, and down, so as to support four-posture core navigation. 
     It is emphasized that while thumb-extended, pointing-finger, flat-hand, and/or first poses may be suitable for four-posture core navigation as described herein, they are examples only and other poses also may be equally suitable. Furthermore, the specific four-posture core navigation arrangements described also are examples only, and other arrangements also may be equally suitable. 
     Now with reference to  FIG. 11A  and  FIG. 11B , previously with regard to  FIG. 3A  and  FIG. 3B  an example method was shown for control using multiple postures of a single pose. The arrangement in  FIG. 3A  and  FIG. 3B  was presented as relatively general. For clarity, a  FIG. 11A  and  FIG. 11B  presents an arrangement that is at least somewhat similar, but that is directed to a more particular example. 
     In  FIG. 11A , a forward interface navigation function is instantiated A onto a processor. The forward interface navigation function invokes, commands, or otherwise causes a forward scrolling of content in an interface, a forward scrolling through content in an interface, or similar. Typically though not necessarily, the forward interface navigation function (and other navigation functions as referenced below) may be instantiated onto a processor in the form of data and/or executable instructions, as loaded from some data store such as a hard drive, solid state drive, etc. 
     In  FIG. 11A , a forward interface navigation function is instantiated A onto a processor. The forward interface navigation function invokes, commands, or otherwise causes a forward scrolling of content in an interface, a forward scrolling through content in an interface, or similar. For example, the interface may be a graphical user interface for an electronic device, such as a head mounted display, though other arrangements may be equally suitable. Typically though not necessarily, the forward interface navigation function (and other navigation functions as referenced below) may be instantiated A onto the processor in the form of data and/or executable instructions, as loaded from some data store such as a hard drive, solid state drive, etc. 
     A back interface navigation function also is instantiated B onto the processor. The back interface navigation function invokes, commands, or otherwise causes a backward scrolling of content in an interface, a backward scrolling through content in an interface, or similar. 
     An affirmative interface navigation function is instantiated C onto the processor. The affirmative interface navigation function invokes, commands, registers, etc. a positive logical state, i.e. “yes”, within the interface. The affirmative interface navigation function thus may accept some option, indicate that some information has been received, confirm completion of an action, etc. 
     A negative interface navigation function is instantiated D onto the processor. The negative interface navigation function invokes, commands, registers, etc. a negative logical state, i.e. “no”, within the interface. The affirmative interface navigation function thus may reject some option, indicate that information has not been received, register that some task is not complete, etc. 
     The forward and back interface navigation functions are opposites, in that forward scrolling may be considered opposite to backward scrolling. Similarly, the affirmative and negative interface navigation functions are opposites, in that affirmative and negative logical indications may be considered opposites. 
     Continuing in  FIG. 11A , a horizontal geometric input axis is defined as A in the processor. The horizontal geometric input axis serves to determine the orientation of inputs to the system, e.g. “right” in one direction along the axis or “left” in an opposite direction along the axis. The horizontal geometric input axis may or may not be displayed to a user for purposes of alignment reference; such display is not required but also is not excluded. It is noted that the horizontal geometric input axis is not necessarily required to be perfectly linear, and indeed may deviate noticeably from linear in certain embodiments. For example, a horizontal axis may be curved to accommodate human ranges of motion (e.g. approximating motion arcs for arms, etc.). 
     A vertical geometric input axis is defined as B in the processor. The vertical geometric input axis likewise serves to determine the orientation of inputs to the system, e.g. “up” in one direction along the axis or “down” in an opposite direction along the axis. The vertical geometric input axis also may or may not be displayed to a user for purposes of alignment reference, and may or may not be strictly linear. 
     Continuing in  FIG. 11A , a forward hand posture input standard is instantiated A in the processor, associated with the forward interface navigation function. That is, the posture that will be accepted as “forward input” for invoking the forward interface navigation function is specified, i.e. defined as some standard. The hand posture input may, for example, be a single pose, that pose being shared with other hand posture input standards (as described below). As a more particular example, the forward hand posture input standard may specify a free space hand pose, with the fingers substantially together and substantially curled/clenched, and with the thumb substantially extended and substantially raised away from the hand. The forward hand posture input standard further may specify that the pose in question is in a posture oriented such that the thumb extends towards the right substantially parallel with the horizontal geometric input axis. 
     Some degree of degeneracy in pose and/or posture also may be defined within the forward hand posture input standard (and likewise the back, affirmative, and negative hand posture input standards). However, degeneracy ranges (if used) also may be defined elsewhere, for example, some general definition that specifies allowed/rejected degeneracy or other variations from ideal inputs throughout a system, as opposed to being specific to any one pose and/or posture. Other arrangements also may be equally suitable. 
     A back hand posture input standard is instantiated B in the processor, associated with the back interface navigation function. The posture accepted as “back input” for invoking the back interface navigation function is specified, i.e. defined as some standard. The back hand posture input standard may specify the free space hand pose referenced with regard to A, and may further specify a posture oriented such that the thumb extends towards the left substantially parallel with the horizontal geometric input axis. 
     An affirmative hand posture input standard is instantiated C in the processor, associated with the affirmative interface navigation function. The posture accepted as “affirmative input” for invoking the affirmative interface navigation function is specified, i.e. defined as some standard. The affirmative hand posture input standard may specify the free space hand pose referenced with regard to A, and may further specify a posture oriented such that the thumb extends upward substantially parallel with the vertical geometric input axis. 
     A negative hand posture input standard is instantiated D in the processor, associated with the negative interface navigation function. The posture accepted as “negative input” for invoking the negative interface navigation function is specified, i.e. defined as some standard. The negative hand posture input standard may specify the free space hand pose referenced with regard to A, and may further specify a posture oriented such that the thumb extends downward substantially parallel with the vertical geometric input axis. 
     Still with reference to  FIG. 11A , a free space hand posture input is sensed by a sensor in communication with the processor. For example, continuing the example of a head-mounted display, a depth camera, RGB camera, or another sensor may image the hand of a user wearing the head-mounted display, so as to acquire data regarding what pose and/or posture (if any) the user is exhibiting. 
     Moving on to  FIG. 11B , a determination is made A in the processor as to whether the free space hand posture input meets the forward hand posture input standard. That is, does the free space hand posture input as sensed in meet whatever criteria are part of the forward hand posture input standard as instantiated A on the processor? To continue the example above, does the free space hand posture input reveal a hand in a thumb extended pose with the thumb oriented to the right? 
     If the determination A is positive, the method continues with step A. In step A, the forward interface navigation function is executed in the processor, such that content is forward scrolled A in the navigation interface. If the determination A is negative, the method skips step A and continues with step B. 
     Continuing in  FIG. 11B , a determination is made B in the processor as to whether the free space hand posture input meets the back hand posture input standard. That is, does the free space hand posture input as sensed in meet whatever criteria are part of the forward hand posture input standard as instantiated B on the processor? To continue the example above, does the free space hand posture input reveal a hand in a thumb extended pose with the thumb oriented to the left? If the determination B is positive, the method continues with step B. In step B, the back interface navigation function is executed in the processor, such that content is backward scrolled B in the navigation interface. If the determination B is negative, the method skips step B and continues with step C. 
     A determination is made C in the processor as to whether the free space hand posture input meets the affirmative hand posture input standard. That is, does the free space hand posture input as sensed in meet whatever criteria are part of the affirmative hand posture input standard as instantiated C on the processor? To continue the example above, does the free space hand posture input reveal a hand in a thumb extended pose with the thumb oriented up? If the determination C is positive, the method continues with step C. In step C, the affirmative interface navigation function is executed in the processor, such that an affirmative logical state is entered C within the navigation interface. If the determination C is negative, the method skips step C and continues with step D. 
     A determination is made D in the processor as to whether the free space hand posture input meets the negative hand posture input standard. That is, does the free space hand posture input as sensed in meet whatever criteria are part of the negative hand posture input standard as instantiated D on the processor? To continue the example above, does the free space hand posture input reveal a hand in a thumb extended pose with the thumb oriented down? If the determination D is positive, the method continues with step D. In step D, the negative interface navigation function is executed in the processor, such that a negative logical state is entered D within the navigation interface. If the determination D is negative, the method skips step D. 
     It is particularly noted that in scrolling forward or back, delivering affirmative, or negatives, as in steps A, B, C, and D, other actions also may be implied. For example, if the interface is a graphical user interface, then any or all of steps A, B, C, and D may result in visible changes to displayed content, and/or other noticeable changes. Although executing the functions A, B, C, and D refer directly to system control through navigation, system control and/or navigation are not required to be invisible or otherwise unnoticeable, and indeed system control and/or interface navigation may have readily perceived effects. To continue the example of a head mounted display, there may be changes to what is displayed thereon, new programs may be activated, hardware systems may be turned on or off, communications may be sent or received, etc. Specific graphical or other visible changes are not specified herein, as embodiments are not limited with regard to what changes may be made or to what degree a system may be controlled; in practice the range of potential control responses is extremely large and varied. Regardless, although navigation is referred to herein at times with regard to the somewhat abstract notion of “an interface”, in practice navigation and/or other control functions may in fact control systems, mechanisms, etc. that are practical and/or physical. 
     Now with reference to  FIG. 12 , although as noted previously it may be useful to support navigation with four functions along two axes (e.g. yes/no and forward/back), as also noted such an arrangement is not necessarily limiting. For example, for certain embodiments, it may be suitable to utilize only a single axis, such as a forward/back axis.  FIG. 13  shows an example arrangement for control using multiple postures of a single pose. 
     In  FIG. 12 , a first control function is established A. For example, the first control function established A may be a forward navigational command in a processor. Control functions have been previously described herein (e.g. with regard to  FIG. 3A  and  FIG. 3B ). A second control function also is established B. For example, the second control function established B may be a back navigational command in a processor. 
     An input axis is established. The input axis may, for example, be a horizontal spatial axis presents the possibility of options to the right or to the left (though other arrangements also may be suitable). Input axes also have been previously described herein. 
     Continuing in  FIG. 3A , a first input standard is established A, associated with the first control function. A second input standard also is established B, associated with the second control function. For example, the first input standard may specify a free space hand input exhibiting a thumb-extended pose, in a posture with the thumb aligned to the right along the input axis. The second input standard may specify a free space hand input exhibiting a thumb-extended pose, in a posture with the thumb aligned to the left along the input axis. 
     Input is then sensed. The input may be, but is not required to be, the pose and/or postures specified with the first and second input standards. 
     Still, with reference to  FIG. 12 , a determination is made A as to whether the input meets the first input standard. If the determination A is positive then the method continues with step A, wherein the first control function is executed (e.g, forward scrolling of/in content in an interface). If the determination A is negative, then the method skips step A and continues with step B. 
     A determination is made B as to whether the input meets the second input standard. If the determination B is positive then the method continues with step B, wherein the second control function is executed (e.g, backward scrolling of/in content in an interface). If the determination B is negative, then the method skips step B. 
     Although the arrangement shown in  FIG. 12  is described with regard to forward and backward control functions, it should be understood that a similar arrangement could be made using affirmative and negative control functions, and/or other control functions or pairs thereof. 
     Now with reference to  FIG. 13 , therein is shown an example embodiment of an apparatus for controlling a system, in schematic form. 
     In the example arrangement of  FIG. 13 , the apparatus includes a processor, with at least one sensor in communication therewith; in the arrangement shown in  FIG. 13  there are two sensors A and B, but this is an example only and not all embodiments require or will necessarily have more than one sensor. 
     The processor is adapted to execute executable instructions instantiated thereon. The choice of processor is not limited. Suitable processors include but are not limited to digital electronic microprocessors. Although the processor is referred to in at least some places herein as a self-contained physical device for purposes of clarity, this is not required, and other arrangements may be suitable. For example, the processor may constitute two or more physical processors working cooperatively, a processing capability in a network without a well-defined physical form, etc. 
     The sensors A and B are adapted to sense input, for example (but not necessarily only) free space input such as hand postures. As shown in  FIG. 13 , the sensors A and B are depicted as imagers, such as a color digital camera, depth camera, pair of stereo cameras, etc. However, these are examples only, and embodiments are not limited with regard to what sensors may be utilized therein. Suitable sensors may include, but are not limited to, digital and/or analog cameras (whether operating in grayscale and/or color, and whether sensing visible light, infrared light, thermal radiation, and/or ultraviolet light) depth cameras, structured light sensors, time-of-flight sensors, and ultrasonic sensors. 
     The sensor(s) A and B are in communication with the processor. As shown, the sensors A and B are illustrated directly connected with the processor, but this is an example only. Other arrangements may be equally suitable, including but not limited to arrangements wherein one or more sensors are not part of the apparatus at all, and/or wherein a sensor is physically distant from the apparatus. So long as suitable data may be obtained for determining the presence of input, embodiments are not limited with regard to sensors. In addition, embodiments are not limited with regard to how the processor and sensors A and B may be in communication. Although a hard-wired link may be suitable as shown in  FIG. 13 , other arrangements, including but not limited to wireless communication may be equally suitable. 
     As may be seen, the arrangement of  FIG. 13  includes several data entities A through E disposed on the processor. Data entities A through E are functional constructs, for example of data and/or executable instructions instantiated onto a processor. The data entities A through E as shown in  FIG. 13  are adapted to enable certain functions by/on the processor. However, the use of data entities as shown is an example only; comparable functional entities other than data entities also may be suitable. For example, the functions for the data entities A through E (described below) could be carried out by hardwired electronics, or potentially even by mechanical systems or other systems. So long as the specified functionality is present, the particular nature of the data entities A through E (or even whether the functions are carried out by data entities per se) is not limiting. 
     Still with reference to  FIG. 13 , the data entities as shown therein are a control function establisher A, an axis establisher B, an input standard establisher C, an input evaluator D, and a control function executor E. 
     The control function establisher A is adapted to establish control functions on the processor. For example, the control function establisher A may establish first, second, third, and fourth control functions on the processor, those control functions including a positive parameter progression, a negative parameter progression, a first logical binary state, and a second logical binary state. As a more specific example, the control functions may include a forward content scroll, a backward content scroll, a logical affirmative, and a logical negative. However, the particulars of the control functions are not limited, and other arrangements may be equally suitable. 
     In addition, the manner by which the control functions are established by the control function establisher A is not limited. In certain embodiments, the control function establisher may generate (e.g. procedurally through the use of executable instructions) the various control functions. However, the control functions alternatively may be read from stored information (e.g. a data store), or the control functions themselves may be present within the control function establisher A itself. Similar variability may apply to the nature and/or function of the axis establisher B, input standard establisher C, input evaluator D, and control function executor E. 
     Again in reference to  FIG. 13 , the axis establisher B is adapted to establish first and second direction axes, including but not limited to dimensional axes that are perpendicular to one another such as a vertical axis and a horizontal axis. 
     The input standard establisher C is adapted to establish first, second, third, and fourth input standards, the input standards being associated with the first, second, third, and fourth control functions respectively. Typically though not necessarily, input standard establisher C is adapted to establish the first, second, third, and fourth input standards such that all specify the same pose, oriented in different directions (e.g. along first and second axes) so as to form a distinct posture for each of the first, second third and fourth input standards. 
     The input evaluator D is adapted to evaluate input as received by the sensors A and B (or in embodiments with only one, the sensor singular) so as to determine whether the input satisfies any of the first, second third, and fourth input standards. Typically though not necessarily, this may be accomplished by performing actions such as (but not limited to) analyzing the data received from the sensors A and B computationally, constructing a model of the input (e.g. a hand model), comparing data, computations, and or models against specified values and/or models in the various input standards, etc. However, other arrangements may be equally suitable. 
     The control function executor E is adapted to execute the first, second, third, and fourth control functions (as established by the control function establisher A), in the event that input satisfies the first, second, third, or fourth input standard respectively. Typically though not necessarily the control function executor E may execute an indicated control function by issuing processor commands, activating executable processor instructions, etc., but other arrangements may be equally suitable. 
     In addition, a number of optional elements are shown in  FIG. 13 . The apparatus as shown does not require such additional elements, but neither are additional elements prohibited, and certain such additional elements may be useful and/or desirable for at least certain embodiments. 
     A communicator is shown in communication with the processor, adapted to communicate between the processor and other entities. Where a communicator is present, embodiments are not limited with regard to the communicator. Typically though not necessarily a communicator may be a wireless communicator, such as a Wi-Fi or Bluetooth communicator, but other arrangements may be equally suitable. It is noted that a communicator may serve to accept data entities, executable instructions, sensor information, etc. from external sources to the processor, and/or to transmit control functions from the processor to external recipients. 
     A data store such as a hard drive, solid state drive, etc. is shown in communication with the processor. As noted previously, executable instructions, the various data entities A through E, and/or other information may be instantiated onto the processor from a data store. Other functions for a data store also may be equally suitable, for embodiments wherein a data store is present. Where present, embodiments are not limited with regard to what data store may be suitable; although the data store is depicted as a hard drive in  FIG. 13 , this is an example only and other arrangements may be equally suitable. 
     A display is shown in  FIG. 13 . Although embodiments do not necessarily require a display, a display as may be present in certain embodiments is shown herein as an example. For example, for control functions addressed to interface navigation, a display may serve to output the interface to a user, update that interface or show other information in response to user inputs (and control commands executed in response thereto), etc. As illustrated in  FIG. 13 , the display is a stereo display, with left and right screens adapted to output to the left and right eyes of a viewer. However, this also is an example only. Embodiments are not limited with regard to the type of display. Typically, although not necessarily, the display may be a visual display. Where present, a range of devices may be suitable for use as the display, including but not limited to light emitting diodes (LED), organic light emitting diodes (OLED), plasma screen panels (PDP), liquid crystal displays (LCD), etc. Likewise, the use of projected or transmitted displays, where the viewed surface is essentially a passive screen for an image projected or otherwise transmitted after being generated elsewhere, may also be suitable. Other arrangements including but not limited to systems that display images directly onto a user&#39;s eyes also may be equally suitable. Either digital or analog display technologies may be suitable. Furthermore, embodiments are not limited only to the use of visual displays as a display. 
     Now with reference to  FIG. 14 , embodiments are not particularly limited with regard to form and may be disposed on and/or incorporated into many shapes and/or other devices. Suitable configurations include but are not limited to the example shown in  FIG. 14 , which illustrates an apparatus configured in the form of a head-mounted display resembling a pair of glasses. 
     As shown in  FIG. 14 , the example embodiment of the apparatus therein includes a body having a form similar to a pair of glasses, and adapted to be worn in a similar fashion. A processor adapted for executing executable instructions is disposed on the body. Although not visible as distinct entities, the processor may support thereon data entities similar to those shown in  FIG. 13  (such as control function establisher A, axis establisher B, input standard establisher C, input evaluator D, and/or control function executor E.) 
     The apparatus as shown in  FIG. 14  includes sensors A and B, both disposed on the body. The apparatus also shows several features noted previously as optional, such as a communicator, a data store, and displays A and B, disposed on the body. The particular arrangement and configuration of the features shown in  FIG. 14  is an example only, and should not be understood as limiting. 
     However, as a particular example, it is noted that in the arrangement shown in  FIG. 14  the body is configured and sensors A and B are disposed thereon such that when the body is worn by a viewer, sensors A and B would be substantially aligned with the lines of sight of the viewer&#39;s eyes, and could potentially encompass fields of view at least somewhat comparable to those of the viewer&#39;s eyes, assuming sensors A and B exhibit fields of view similar in extent to those of the viewer. (Reference is made here to the acceptance and/or rejection of certain potentially valid inputs as described with regard to  FIG. 8A  through  FIG. 9B , based at least in part on point of view. This point of view for sensors detecting input may have bearing on certain functions, for at least certain embodiments.) Similarly, in the arrangement shown the body is configured and the displays A and B disposed thereon such that when the body is worn by a viewer, the displays A and B would be proximate to and substantially in front of the viewer&#39;s eyes. 
     However, it is emphasized that the arrangement in  FIG. 14  is an example only, and that other arrangements may be equally suitable, including but not limited to other head-mounted displays and devices and systems other than a head-mounted display. 
     Moving on to  FIG. 15 , therein is shown a block diagram of an apparatus that may perform various operations, and store various information generated and/or used by such operations, according to an embodiment of the disclosed technique. The apparatus may represent any computer or processing system described herein. The processing system is a hardware device on which any of the other entities, components, or services depicted in the examples of  FIG. 1  through  FIG. 14  (and any other components described in this specification) may be implemented. The processing system includes one or more processors and memory coupled to an interconnect. The interconnect is shown in  FIG. 15  as an abstraction that represents any one or more separate physical buses, point to point connections, or both connected by appropriate bridges, adapters, or controllers. The interconnect, therefore, may include, for example, a system bus, a Peripheral Component Interconnect (PCI) bus or PCI-Express bus, a HyperTransport or industry standard architecture (ISA) bus, a small computer system interface (SCSI) bus, a universal serial bus (USB), IIC (I2C) bus, or an Institute of Electrical and Electronics Engineers (IEEE) standard bus, also called “Firewire”. 
     The processor(s) is/are the central processing unit of the processing system and, thus, control the overall operation of the processing system. In certain embodiments, the processor(s) accomplish this by executing software or firmware stored in memory. The processor(s) may be, or may include, one or more programmable general-purpose or special-purpose microprocessors, digital signal processors (DSPs), programmable controllers, application specific integrated circuits (ASICs), programmable logic devices (PLDs), trusted platform modules (TPMs), or the like, or a combination of such devices. 
     The memory is or includes the main memory of the processing system. The memory represents any form of random access memory (RAM), read-only memory (ROM), flash memory, or the like, or a combination of such devices. In use, the memory may contain a code. In one embodiment, the code includes a general programming module configured to recognize the general-purpose program received via the computer bus interface and prepare the general-purpose program for execution at the processor. In another embodiment, the general programming module may be implemented using hardware circuitry such as ASICs, PLDs, or field-programmable gate arrays (FPGAs). 
     The network adapter, a storage device(s), and I/O device(s), are also connected to the processor(s) through the interconnect The network adapter provides the processing system with the ability to communicate with remote devices over a network and may be, for example, an Ethernet adapter or Fibre Channel adapter. The network adapter may also provide the processing system with the ability to communicate with other computers within the cluster. In some embodiments, the processing system may use more than one network adapter to deal with the communications within and outside of the cluster separately. 
     The I/O device(s) can include, for example, a keyboard, a mouse or other pointing device, disk drives, printers, a scanner, and other input and/or output devices, including a display device. The I/O device(s) also may include, for example, cameras and/or other imagers adapted to accept visual input including but not limited to postures and/or gestures. The display device may include, for example, a cathode ray tube (CRT), liquid crystal display (LCD), or some other applicable known or convenient display device. The display device may take various forms, including but not limited to stereo displays suited for use in near-eye applications such as head mounted displays or other wearable devices. 
     The code stored in memory may be implemented as software and/or firmware to program the processor(s) to carry out actions described herein. In certain embodiments, such software or firmware may be initially provided to the processing system by downloading from a remote system through the processing system (e.g., via network adapter). 
     The techniques herein may be implemented by, for example, programmable circuitry (e.g. one or more microprocessors) programmed with software and/or firmware, or entirely in special-purpose hardwired (non-programmable) circuitry, or in a combination of such forms. Special-purpose hardwired circuitry may be in the form of, for example, one or more AISCs, PLDs, FPGAs, etc. 
     Software or firmware for use in implementing the techniques introduced here may be stored on a machine-readable storage medium and may be executed by one or more general-purpose or special-purpose programmable microprocessors. A “machine-readable storage medium”, as the term is used herein, includes any mechanism that can store information in a form accessible by a machine. 
     A machine can also be a server computer, a client computer, a personal computer (PC), a tablet PC, a laptop computer, a set-top box (STB), a personal digital assistant (PDA), a cellular telephone, an iPhone, a Blackberry, a processor, a telephone, a web appliance, a network router, switch, or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. 
     A machine-accessible storage medium or a storage device(s) includes, for example, recordable/non-recordable media (e.g., ROM; RAM; magnetic disk storage media; optical storage media; flash memory devices; etc.), etc., or any combination thereof. The storage medium typically may be non-transitory or include a non-transitory device. In this context, a non-transitory storage medium may include a device that is tangible, meaning that the device has a concrete physical form, although the device may change its physical state. Thus, for example, non-transitory refers to a device remaining tangible despite this change in state. 
     The term “logic”, as used herein, may include, for example, programmable circuitry programmed with specific software and/or firmware, special-purpose hardwired circuitry, or a combination thereof. 
     The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.