Description Title of Invention: INFORMATION PROCESSING APPARATUS, INFORMATION PROCESSING METHOD, AND PROGRAM Technical Field [0001] The present disclosure relates to an information processing apparatus, an information processing method, and a program encoded on a non-transitory computer readable medium. Background Art [0002] In recent years, a technique called augmented reality (AR) in which additional in formation is superimposed on a real image so as to be presented to a user has attracted attention. In the AR technique, information presented to a user is also called annotation and the information is visualized as various types of virtual objects such as, for example, texts, icons or animation. As an example of the AR technique, Patent Literature 1 discloses a technique in which an image of a virtual object imitating a real object such as furniture is superimposed on a real image so as to be displayed, thereby easily attempting to arrange furniture and so on. Citation List Patent Literature [0003] PTL 1: JP 2003-256876A Summary Technical Problem [0004] The above-described AR technique is realized, for example, by capturing a real image using a device held by the user and by superimposing the display of a virtual object related to a real object reflected in the image. In this case, for example, postures of the reflected real object are variously changed depending on the movement of the user or changes in methods of holding the device. That is to say, even in the same real object, a size or angle in the image is changed depending on the circumstances. Thus, even if a captured image of the same real object is displayed, there are cases where ap propriate display methods of additional information are different. [0005] Therefore, it is desirable to provide novel and improved information processing apparatus, information processing method, and program encoded on a non-transitory computer readable medium, capable of appropriately displaying additional information so as to be suitable for a posture of a real object. Solution to Problem [0006] In one embodiment, the present invention includes apparatus including an image processor configured to receive a video including an object, determine a positional re lationship between the apparatus and the object, and change a positional relationship between an image superimposed on the video and the object when the positional rela tionship between the apparatus and the object changes. Advantageous Effects of Invention [0007] As described above, according to embodiments of the present disclosure, it is possible to appropriately display additional information so as to be suitable for a posture of a real object. Brief Description of Drawings [0008] [fig. 1]FIG. 1 is a diagram illustrating a reference technique regarding a first em bodiment of the present disclosure; [fig.2]FIG. 2 is a block diagram illustrating an example of the functional configuration of the information processing apparatus according to the first embodiment of the present disclosure; [fig.3]FIG. 3 is a diagram illustrating a first state where a virtual object is displayed by the information processing apparatus according to the first embodiment of the present disclosure; [fig.4]FIG. 4 is a diagram illustrating a second state where a virtual object is displayed by the information processing apparatus according to the first embodiment of the present disclosure; [fig.5]FIG. 5 is a diagram illustrating a change in display of a virtual object by the in formation processing apparatus according to the first embodiment of the present disclosure; [fig.6]FIG. 6 is a flowchart illustrating an example of the process flow of image display process in the information processing apparatus according to the first em bodiment of the present disclosure; [fig.7]FIG. 7 is a flowchart illustrating an example of the process flow of display target setting process in the information processing apparatus according to the first em bodiment of the present disclosure; [fig.8]FIG. 8 is a diagram illustrating an example of the alternative selection and the message display according to the first embodiment of the present disclosure; [fig.9]FIG. 9 is a diagram illustrating a first state where a virtual object is displayed by an information processing apparatus according to a second embodiment of the present disclosure; [fig.l0]FIG. 10 is a diagram illustrating a second state where a virtual object is displayed by the information processing apparatus according to the second em bodiment of the present disclosure; [fig. 11]FIG. 11 is a diagram illustrating a change in display of a virtual object by the information processing apparatus according to the second embodiment of the present disclosure; [fig. 12]FIG. 12 is a diagram illustrating a positional relationship between a detected real object and a device according to a third embodiment of the present disclosure; [fig.l3]FIG. 13 is a diagram illustrating a first state where a virtual object is displayed by the information processing apparatus according to the third embodiment of the present disclosure; [fig.l4]FIG. 14 is a diagram illustrating a second state where a virtual object is displayed by the information processing apparatus according to the third embodiment of the present disclosure; [fig. 15]FIG. 15 is a diagram illustrating a change in display of a virtual object by the information processing apparatus according to the first embodiment of the present disclosure; [fig.l6]FIG. 16 is a flowchart illustrating an example of the process flow of display target setting process in the information processing apparatus according to the third embodiment of the present disclosure; [fig.l7]FIG. 17 is a block diagram illustrating another example of the functional con figuration of an information processing apparatus according to an embodiment of the present disclosure; [fig.l8]FIG. 18 is a block diagram illustrating further another example of the functional configuration of the information processing apparatus according to an em bodiment of the present disclosure; and [fig. 19]FIG. 19 is a block diagram illustrating a hardware configuration of the in formation processing apparatus. Description of Embodiments [0009] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. [0010] In addition, the description will be made in the following order. 1. First Embodiment (an example of changing a display position relative to a real object) 2. Second Embodiment (an example of changing an amount of displayed in formation) 3. Third Embodiment (an example of changing a content of displayed information) 4. Other Embodiments regarding Apparatus Configuration 5. Supplement [0011] 1. First Embodiment The first embodiment of the present disclosure will be described with reference to FIGS. 1 to 8. In the first embodiment of the present disclosure, a display position of a virtual object relative to a real object is changed depending on a relative positional r e lationship between the real object reflected in an image and a device capturing the image. [0012] 1-1. Reference Technique First, a description will be made of a reference technique for better understanding of the present embodiment. FIG. 1 is a diagram illustrating the reference technique regarding the first embodiment of the present disclosure. [0013] An information processing apparatus 10 related to the reference technique is shown in FIG. 1. The information processing apparatus 10 includes an image pickup unit (not shown) and a display unit 12, and the information processing apparatus 10 executes an AR application. [0014] Here, the display unit 12 displays an image where the information processing apparatus 10 superimposes a virtual object obj_v related to a real object obj_r on an image in which the real object obj_r captured by the image pickup unit is reflected. In the shown example, in a case where the real object obj_r (a book) is captured from the front side as shown in (a) of FIG. 1, and in a case where the real object obj_r is captured obliquely as shown in (b) of FIG. 1, the virtual object obj_v (an image regarding a content of the book) is transformed into different forms and is displayed. In other words, the virtual object obj_v is transformed and displayed to be suitable for the change in the appearance due to the change in a posture of the real object obj_r. [0015] As such, in the AR application, there are cases where a virtual object is transformed to be suitable for a posture of a real object and is disposed in an AR space. Thereby, for example, a user recognizes the virtual object as if the virtual object is reflected on a surface of a real object and exists therein, and thus can easily understand a relationship between the real object and the virtual object. [0016] However, as shown in (b) of FIG. 1 of the illustrated example, there is a case where it is difficult for the transformed virtual object obj_v to be visually recognized according to a posture of the real object obj_r. In this case, it is difficult to say that the virtual object obj_v is displayed in an appropriate manner. [0017] Therefore, in the present embodiment, by changing a display position of a virtual object relative to a real object depending on a positional relationship between the real object reflected in an image and a device capturing the image, even in the case, it is possible to display the virtual object obj_v in an appropriate manner. [0018] 1-2. Apparatus Configuration Next, with reference to FIG. 2, a functional configuration according to the present disclosure will be described. FIG. 2 is a block diagram illustrating an example of the functional configuration of the information processing apparatus according to the first embodiment of the present disclosure. [0019] Referring to FIG. 2, an information processing apparatus 100 according to the present embodiment includes an image pickup unit 102, an image recognition unit 104, a model DB 106, a positional relationship detection unit 108, a selection unit 110, an object DB 112, a display target information output unit 114, a message information output unit 116, a display control unit 118, and a display unit 120. [0020] In the present embodiment, the information processing apparatus 100 will be described as a terminal apparatus into which the respective units including the image pickup unit and the display unit, such as a smart phone, a tablet type PC (Personal Computer), PDA (Personal Digital Assistant), a portable gaming machine, or a portable music player are integrated. However, the information processing apparatus 100 may be other information processing apparatuses such as a notebook type or desktop type PC. In this case, for example, the image pickup unit or the display unit may be provided separately from the other units. In addition, in a case where the in formation processing apparatus 100 is divided into a plurality of units, the "information processing apparatus 100" in the disclosure such as a "positional relationship between the information processing apparatus 100 and a real object" or an "angle of a real object relative to the information processing apparatus 100" indicates a portion at which the image pickup unit of the information processing apparatus 100 is provided unless otherwise specifically defined herein. [0021] Among the above-described functional configurations, the image pickup unit 102 is realized by, for example, an image pickup device included in the information processing apparatus 100. In addition, the image recognition unit 104, the positional relationship detection unit 108, the selection unit 110, the display target information output unit 114, the message information output unit 116, and the display control unit 118 are realized by, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory) of the information processing apparatus 100 being operated according to a program. The model DB 106 and the object DB 112 are realized by, for example, an internal or external storage device of the information processing apparatus 100. The display unit 120 is realized by, for example, a variety of displays which are included in the information processing apparatus 100 as output devices or are connected to the information processing apparatus 100 as external connection devices. [0022] The image pickup unit 102 captures a real space to generate an image. The image pickup unit 102 may capture moving images. The moving images are configured by a plurality of images forming consecutive frames. The image pickup unit 102 provides the generated image to both the image recognition unit 104 and the display control unit 118. At this time, the generated image may be temporarily stored in, for example, the RAM or the storage device. [0023] The image recognition unit 104 performs object recognition using data stored in the model DB 106. The model DB 106 is a database which stores in advance model data regarding shapes or appearances of objects which are targets recognized by the in formation processing apparatus 100. In the present embodiment, targets recognized by the information processing apparatus 100 are any objects in a real space. The model data includes data defining a shape of each object, image data such as a predetermined symbol mark or a text label added to each object, data of a feature amount set extracted from an existing image for each object, and the like. [0024] More specifically, the image recognition unit 104 uses an image captured by the image pickup unit 102 as an input image, thereby recognizing which object is reflected in the input image. The image recognition unit 104 compares, for example, a feature point set extracted from the input image with a shape of an object defined by the model data. In addition, the image recognition unit 104 may compare image data such as a symbol mark or a text label defined by the model data with the input image. Fur thermore, the image recognition unit 104 may compare a feature amount of an image of an existing object defined by the model data with a feature amount extracted from the input image. [0025] The positional relationship detection unit 108 detects a positional relationship between the object recognized by the image recognition unit 104 and the information processing apparatus 100 (more specifically, the image pickup unit 102). In the present embodiment, an angle of the object relative to the information processing apparatus 100 is used as a positional relationship between the object and the information processing apparatus 100. This angle is expressed as, for example, a tilt from a reference posture which is set for an object in advance. In other words, in the present embodiment, the positional relationship detection unit 108 detects a posture rela tionship between the object and the information processing apparatus 100 as the p o sitional relationship between the object and the information processing apparatus 100. [0026] More specifically, the positional relationship detection unit 108 uses an image captured by the image pickup unit 102 as an input image, thereby detecting a posture of an object reflected in the input image. Here, in the present embodiment, a posture of the object is collectively expressed by a 4*4 homogeneous transformation matrix in dicating transformation between a model coordinate system in the model data stored in the model DB 106 and a coordinate system of the object reflected in the input image. The positional relationship detection unit 108 extracts an angle of the object relative to the information processing apparatus 100 from the homogeneous transformation matrix. [0027] In addition, detailed examples of the positional relationship acquired by the p o sitional relationship detection unit 108 will be described later. Since a process performed by the positional relationship detection unit 108 is common to a process performed by the image recognition unit 104 such as referring to the model DB 106, the process may be performed along with the process performed by the image recognition unit 104. [0028] The selection unit 110 selects a display target object which is superimposed on an image, from a virtual object group including a plurality of kinds of virtual objects related to the real object, according to the positional relationship detected by the p o sitional relationship detection unit 108. More specifically, the selection unit 110 selects a virtual object from a virtual object group including a plurality of virtual objects of which the display positions relative to the real object are different from each other, according to the angle of the real object relative to the information processing apparatus 100. The virtual object is displayed at a position which is easily visually recognized by a user. The angle of the real object relative to the information processing apparatus 100 is acquired by the positional relationship detection unit 108. Such a virtual object and an example of the selection of a virtual object by the selection unit 110 will be described later. [0029] In the present embodiment, data of the virtual object group is stored in the object DB 112. The object DB 112 may be a database which stores in advance data of a virtual object group corresponding to each real object. In addition, the object DB 112 may be a database which temporarily stores a virtual object group which corresponds to a real object recognized by the image recognition unit 104 and is downloaded from an external device. [0030] Furthermore, the object DB 112 may be a database which temporarily stores a virtual object which is obtained by processing a part of or the overall real object reflected in an image captured by the image pickup unit 102. The processing of the real object is performed by a processing unit (not shown). The processing unit may generate a virtual object by processing an image according to a result of a selection made by the selection unit 110. In this case, for example, the selection unit 110 refers to in formation indicating "what kind of virtual object can be generated" stored in the object DB 112. The selection unit 110 also selects the kind of virtual object to be displayed and instructs the processing unit to generate the virtual object. [0031] In addition, as described later as an example of the alternative selection and the message display, in a case where a selected virtual object cannot be displayed in an image region, the selection unit 110 may make an alternative selection of a virtual object which can be displayed in the image region regardless of the selection result. [0032] In addition, the selection unit 110 may adjust a selection result such that the same kind of virtual object is selected for a plurality of real objects related to each other. In this case, for example, the selection unit 110 may average results detected by the p o sitional relationship detection unit 108 for the respective real objects. The selection unit 110 also may use the averaged result as a positional relationship common to the respective real objects. In addition, the selection unit 110 may count the results detected by the positional relationship detection unit 108 for the respective real objects and may use a detection result detected from more real objects as a positional rela tionship common to the respective real objects. Thereby, for example, the kinds of virtual objects displayed for a plurality of real objects related to each other can be unified, and the unification of the virtual objects for the real objects can be shown to a user. [0033] The display target information output unit 114 outputs information of the display target object selected by the selection unit 110 to the display control unit 118 such that the information is superimposed on the image captured by the image pickup unit 102 so as to be displayed. Here, the output information of the display target object may be image data itself of a virtual object or may be identification information such as an ID for separately referring to the image data of the virtual object. Here, in a case of outputting the image data of the virtual object, the display target information output unit 114 may generate a superimposed image of the virtual object, for example, according to a positional relationship between the real object and the information processing apparatus 100. The positional relationship is detected by the positional rela tionship detection unit 108. The display target information output unit 114 also may output information of the superimposed image to the display control unit 118. For this process, the display target information output unit 114 may refer to the object DB 112. [0034] The message information output unit 116 is additionally provided. The message in formation output unit 116 generates information of a message which is superimposed on an image and displayed, and the message information output unit 116 outputs the information to the display control unit 118. For example, in a case where an alternative display target object is selected on account of restriction of a region of an image captured by the image pickup unit 102, as described later, the message information output unit 116 generates information of a message prompting a user to change a region of the image by moving the image pickup unit 102, and the message in formation output unit 116 outputs the information to the display control unit 118. [0035] The display control unit 118 superimposes the virtual object which is a display target object on the image captured by the image pickup unit 102. The superimposition uses the information outputted from the display target information output unit 114. The display control unit 118 also causes the display unit 120 to display the superimposed result as an AR application image. At this time, the display control unit 118 may generate a superimposed image where the display target object is disposed and transformed to be suitable for the position, posture and size of the real object reflected in the image, and the display control unit 118 may superimpose the superimposed image on the image. As described above, the superimposed image may be generated by the display target information output unit 114. When the superimposed image is generated, the display control unit 118 may use, for example, information indicating the positional relationship between the real object and the information processing apparatus 100. The positional relationship is detected by the positional relationship detection unit 108. In a case where the message information output unit 116 is provided, the display control unit 118 superimposes a message on the image by further using information output from the message information output unit 116. [0036] The display unit 120 presents the AR application image to a user. The AR ap plication image is generated by the display control unit 118. As described above, the display unit 120 is realized by various display devices which are formed integrally with or separately from the information processing apparatus 100. The display unit 120 may be, for example, a display screen using an LCD (Liquid Crystal Display), an OLED (Organic Light-Emitting Diode) or a PDP (Plasma Display Panel), or a seethrough type or a non-see-through type HMD (Head Mounted Display) which is installed by a user. [0037] As described above, in the information processing apparatus 100 according to the present embodiment, a display target object is selected according to a positional rela tionship between a real object and the information processing apparatus 100. Also, the display target object is selected from a virtual object group including a plurality of kinds of virtual objects related to the real object. In addition, here, the "plurality of kinds of virtual objects" are virtual objects where a superimposed image is generated according to a plurality of pieces of image data (in other words, original data) which are different from each other. The plurality of pieces of image data are stored in the object DB 112, such as, for example, an "image which looks as if it exists in an inner space of a real object" or an "image which looks as if it protrudes from a real object". In addition, the "virtual object" is an object indicating additional information (annotation) for a real object as described above. [0038] 1-3. Example of Display Change Next, an example of the display change according to the present embodiment will be described with reference to FIGS. 3 to 5. FIG. 3 is a diagram illustrating a first state where a virtual object is displayed by the information processing apparatus according to the first embodiment of the present disclosure. FIG. 4 is a diagram illustrating a second state where a virtual object is displayed by the information processing apparatus according to the first embodiment of the present disclosure. FIG. 5 is a diagram illustrating a change in display of a virtual object by the information processing apparatus according to the first embodiment of the present disclosure. [0039] FIG. 3 shows the first state where a virtual object is displayed by the information processing apparatus 100 according to the present embodiment. As described above, in the present embodiment, the kind of virtual object which is a display target is selected according to an angle of a real object relative to the information processing apparatus 100. In the shown example, in the first state, since an angle Al of the real object obj_r (a book) relative to the information processing apparatus 100 is relatively small, a virtual object obj_vl (an image regarding a content of the book) which looks as if it exists in an inner space of the real object obj_r is displayed. In the following de scription, display of the virtual object when the real object obj_r is reflected in the image in a state close to front view is referred to as "front view display". [0040] Here, an angle A of the real object obj_r relative to the information processing apparatus 100 may be expressed as a tilt of a posture of the real object obj_r from a reference posture when a line of sight direction from the image pickup unit 102 of the information processing apparatus 100 is used as a reference. The reference posture of a real object is, for example, a posture which is defined in advance for each real object, and may be a posture of a real object according to the above-described model co ordinate system. In the real object obj_r (a book) in the shown example, a posture where the cover thereof faces the image pickup unit 102 is set as the reference posture. Here, since the real object obj_r has a plate shape, an angle A is defined as an angle formed by a line perpendicular to the surface and a line of sight from the image pickup unit 102. In addition, a shape of the real object obj_r is not limited to the plate shape, and may be any shape. Therefore, the angle A of the real object obj_r relative to the in formation processing apparatus 100 may be defined variously in addition to the shown example. [0041] FIG. 4 shows the second state where a virtual object is displayed by the information processing apparatus 100 according to the present embodiment. In the shown example, in the second state, since an angle A2 of the real object obj_r (a book) relative to the information processing apparatus 100 is relatively large, a virtual object obj_v2 (an image regarding a content of the book) which looks as if it protrudes from the real object obj_r is displayed. In the following description, the display of virtual object when the real object obj_r is reflected in the image in a state of oblique view is referred to as "oblique view display". [0042] As such, in the present embodiment, the virtual object obj_vl and the virtual object obj_v2 of which display positions relative to the real object obj_r are different from each other are selectively displayed according to a positional relationship between the information processing apparatus 100 and the real object obj_r. In the shown example, the virtual object obj_vl and the virtual object obj_v2 have different positions in the depth direction when the surface of the real object obj_r is used as a reference surface. More specifically, in a case where the real object obj_r is reflected in the image in a state close to front view, the virtual object obj_vl which looks as if it is reflected in the real object obj_r and exists therein is displayed. On the other hand, in a case where the real object obj_r is reflected in the image in a state of oblique view, the virtual object obj_v2 which looks as if it protrudes from the surface of the real object obj_r is displayed. [0043] Thereby, a user can be presented the virtual object obj_v which is easily visually recognized and where a relationship with the real object obj_r is also easily u n derstood, so as to be suitable for each posture even in a case where a posture of the real object obj_r reflected on an image is variously changed. In addition, here, although an example where a display target object is selected from a virtual object group including the virtual object obj_vl in the front view display and the virtual object obj_v2 in the oblique view display has been described, virtual objects included in the virtual object group are not limited to these two kinds. For example, more kinds of virtual objects may be included in the virtual object group, and display target objects may be changed in more steps according to a posture relationship between a real object and the in formation processing apparatus 100. Further, the changes of the positional relationship between the virtual and real object may be performed linearly or non-linearly. [0044] FIG. 5 shows an example of the change in display of a virtual object by the in formation processing apparatus 100 according to the present embodiment. As described above, in the present embodiment, display of a virtual object by the in formation processing apparatus 100 is varied depending on an angle of a real object relative to the information processing apparatus 100. In addition, in the example described here, an angle A of a plate-shaped real object obj_r relative to the in formation processing apparatus 100 is defined as an angle formed by a line perpendicular to the surface of the real object obj_r and a line of sight from the image pickup unit 102 of the information processing apparatus 100. FIG. 5 is a diagram i l lustrating a positional relationship between the information processing apparatus 100 and the real object obj_r through simplification only in one direction on the twodimensional plane in relationships between the angle A and the front view display and the oblique view display of the virtual object. As will be readily apparent to a person skilled in the art, in practice, similar relationship is established for any direction on a three-dimensional space. [0045] In the shown example, when the information processing apparatus 100 faces the real object obj_r, the angle A is 0(deg). In a state of A=0(deg), display of the virtual object is the front view display as in a case of the angle A=A1 shown in FIG. 3. If the in formation processing apparatus 100 is gradually tilted with respect to the real object obj_r from the state and the angle A exceeds a threshold value Tl, the display of the virtual object is changed to the oblique view display as in a case of the angle A=A2 shown in FIG. 4. On the other hand, if the information processing apparatus 100 gradually comes close to the front surface of the real object obj_r from the state where the display of the virtual object is the oblique view display and the angle A becomes smaller than a threshold value T2, then the display of the virtual object is changed to the front view display. [0046] As such, in the present embodiment, the kind of virtual object which becomes a display target object is selected using a threshold value set as an index value (the angle A) regarding a positional relationship between the information processing apparatus 100 and the real object obj_r. In a case where the image pickup unit 102 captures moving images and the kind of virtual object is selected for each of images forming consecutive frames, a different threshold value may be used depending on a virtual object which has been displayed until then, that is, the kind of virtual object selected in an image of the previous frame, such as the above-described threshold values Tl and T2. As such, by giving hysteresis to the selection of a virtual object, it is possible to prevent reduction in visibility occurring since display of the virtual object is frequently changed due to vibration of the angle A around a threshold value caused by camera shake, etc. [0047] 1-4. Example of Process Flow Next, with reference to FIGS. 6 and 7, a description will be made of an example of the process flow performed by the information processing apparatus according to the present embodiment. FIG. 6 is a flowchart illustrating an example of the process flow of image display process in the information processing apparatus according to the first embodiment of the present disclosure. FIG. 7 is a flowchart illustrating an example of the process flow of display target setting process in the information processing apparatus according to the first embodiment of the present disclosure. [0048] FIG. 6 is a flowchart illustrating an image display process according to the present embodiment. The image display process described here is a series of processes performed until a virtual object is superimposed on the image so as to be displayed after the information processing apparatus 100 acquires an image for a real space. In the shown example, the image pickup unit 102 captures moving images, and thus the image display process is repeatedly performed for the respective images forming the consecutive frames. [0049] First, in step S101, the image pickup unit 102 acquires an image. Here, the acquired image is an image which is obtained by capturing a real space and is reflecting a real object obj_r therein. [0050] Next, in step S103, the image recognition unit 104 performs object recognition for the acquired image. Here, the image recognition unit 104 recognizes the real object obj_r reflected in the image by the use of the model data stored in the model DB 106. [0051] Next, in step S105, the positional relationship detection unit 108 detects a positional relationship between the information processing apparatus 100 and the real object obj_r. Here, the positional relationship detection unit 108 detects an angle A of the real object obj_r relative to the information processing apparatus 100. [0052] Next, in step SI07, the selection unit 110 determines whether or not the positional re lationship between the information processing apparatus 100 and the real object obj_r is varied as compared with an image of the previous frame. The positional relationship is indicated by the angle A. If the positional relationship is varied, then the selection unit 110, in step S109, selects a display target object on the basis of the positional rela tionship after being varied. On the other hand, if the positional relationship is not varied, since the kind of virtual object selected as a display target object for the image of the previous frame is continuously used, the selection unit 110 skips step S109. [0053] In addition, a display target selection process in step S109 will be described later with reference to FIG. 7. [0054] Next, in step Sill, the display target information output unit 114 outputs information related to the display target object selected by the selection unit 110 to the display control unit 118. [0055] Next, in step SI 13, the display control unit 118 superimposes the virtual object on the image so as to be displayed on the display unit 120 according to the information of the display target object outputted from the display target information output unit 114. Thereby, the image on which the virtual object appropriately selected by the selection unit 110 is superimposed is presented to a user as an AR application image. [0056] FIG. 7 is a flowchart illustrating a display target setting process according to the present embodiment. The display target setting process described here is a process performed in step S109 of the image display process as described above. In the shown example, the image pickup unit 102 captures moving images, and thus the display target setting process may be also performed for the respective images forming the consecutive frames. [0057] First, in step S201, the selection unit 110 determines whether or not the display of virtual object in the previous frame is the front view display. As described above, the front view display is a display of the virtual object obj_vl which looks as if it exists in an inner space of the real object obj_r when the real object obj_r is reflected in the image in a state close to front view. [0058] Here, if the display of the virtual object in the previous frame is the front view display, then the selection unit 110, in step S203, sets a threshold value Tl as a threshold value of the angle A used to determine a continuous display target. On the other hand, if the display of the virtual object in the previous frame is not the front view display, that is, the display is the oblique view display, the selection unit 110, in step S205, sets a threshold value T2 as the threshold value. As described with reference to FIG. 5, the threshold values Tl and T2 of the angle A in the present embodiment has a relationship of T2 FIG. 17 is a block diagram illustrating another example of the functional con figuration of an information processing apparatus according to an embodiment of the present disclosure. Referring to FIG. 17, an information processing apparatus 200 includes a sensor unit 222 as well as an image pickup unit 102, an image recognition unit 104, a model DB 106, a positional relationship detection unit 108, a selection unit 110, an object DB 112, a display target information output unit 114, a message in formation output unit 116, a display control unit 118, and a display unit 120. [0106] The sensor unit 222 includes a motion sensor group which measures a motion of the image pickup unit 102. The motion sensor may be, for example, an acceleration sensor which measures acceleration of the image pickup unit 102, a gyro sensor which measures a tilt angle, a geomagnetic sensor which measures the azimuth to which the image pickup unit 102 is oriented, or the like. In addition, the sensor unit 222 may include a GPS (Global Positioning System) sensor which receives a GPS signal and measures latitude, longitude and altitude of the apparatus. [0107] In the shown example, the positional relationship detection unit 108 detects a p o sitional relationship between a real object and the information processing apparatus 200 (more specifically, the image pickup unit 102) on the basis of the motion of the image pickup unit 102 acquired by the sensor unit 222. For example, the positional r e lationship detection unit 108 detects a posture of the information processing apparatus 200 on the basis of information of acceleration or tilt angle of the image pickup unit 102. If there is information of a position of a real object, whether or not the real object is on a horizontal plane such as the ground, or whether or not the real object is on a vertical plane such as a wall, it is possible to obtain a positional relationship with the real object by detecting a posture of the information processing apparatus 200. In addition, the positional relationship detection unit 108, as shown in the figure, may detect a positional relationship using information from the sensor unit 222, and may detect a positional relationship using information from the image recognition unit 104 together. [0108] FIG. 18 is a block diagram illustrating still another example of the functional con figuration of an information processing apparatus according to an embodiment of the present disclosure. Referring to FIG. 18, an information processing apparatus 300 includes an image recognition unit 104, a model DB 106, a positional relationship detection unit 108, a selection unit 110, an object DB 112, a display target information output unit 114, a message information output unit 116, and a communication unit 324. [0109] In the shown example, the information processing apparatus 300 does not include the image pickup unit 102, the display control unit 118, and the display unit 120. The in formation processing apparatus 300 is, for example, a server installed on a network, and receives data of an image captured by the image pickup unit of an apparatus which is a client as an input image via the communication unit 324. In addition, the in formation processing apparatus 300 transmits information of a display target object output from the display target information output unit 114 and further information of a message output from the message information output unit 116, to the client via the communication unit 324. An image on which a virtual object is superimposed is generated, and the image is displayed in the display control unit of the terminal apparatus using the transmitted information. [0110] As such, the information processing apparatus according to the embodiments of the present disclosure may not necessarily include the image pickup unit 102 or the display unit 120, and has various configurations. For example, in the above-described in formation processing apparatus 300, the display control unit 118 may be provided, and an image on which a virtual object is superimposed may be generated and transmitted to the client via the communication unit 324. Further, the information processing apparatus may not include the image pickup unit 102 but include the display unit 120, and superimpose a virtual object on an image captured by an external device so as to be displayed. Furthermore, the information processing apparatus may not include the image pickup unit 102 but include the display unit 120, and transmit an image where a virtual object is superposed on a captured image to an external device. [0111] 5. Supplement Finally, with reference to FIG. 19, a description will be made of a hardware con figuration of the information processing apparatus 900 capable of realizing the information processing apparatus according to the embodiments of the present disclosure. FIG. 19 is a block diagram illustrating a hardware configuration of the in formation processing apparatus. [01 12] The information processing device 900 includes a CPU (Central Processing Unit) 901, ROM (Read Only Memory) 903, and RAM (Random Access Memory) 905. Further, the information processing device 900 may include a host bus 907, a bridge 909, an external bus 9 11, an interface 913, an input device 915, an output device 917, a storage device 919, a drive 921, a connection port 923, and a communication device 925. The information processing device 900 may include a processing circuit such as DSP (Digital Signal Processor) in addition to or instead of the CPU 901. [0113] The CPU 901 functions as an arithmetic processing unit and a control unit, and controls the entire operation within the information processing device 900 or a part thereof in accordance with various programs recorded on the ROM 903, the RAM 905, the storage 919, or the removable recording medium 927. The ROM 903 stores programs, operation parameters, and the like used by the CPU 901. The RAM 905 temporarily stores programs used in the execution of the CPU 901, parameters that change as appropriate during the execution, and the like. The CPU 901, the ROM 903, and the RAM 905 are mutually connected by a host bus 907 constructed from an internal bus such as a CPU bus. Further, the host bus 907 is connected to the external bus 911 such as a PCI (Peripheral Component Interconnect/Interface) via the bridge 909. [01 14] The input device 915 is a device used by a user such as, for example, a mouse, a keyboard, a touch panel, a button, a switch, or a lever. The input device 915 may be, for example, a remote control device that uses infrared rays or other radio waves, or an external connection device 929 such as a portable phone corresponding to the operation of the information processing device 900. The input device 915 includes an input control circuit that generates an input signal based on information input by a user and outputs the input signal to the CPU 901. The user can, by operating the input device 915, input various data to the information processing device 900 or instruct the information processing device 900 to perform a processing operation. [0115] The output device 917 includes a device that can visually or audibly inform a user of the acquired information. The output device 917 can be, for example, a display device such as an LCD (liquid crystal display), a PDP (Plasma Display Panel,) an organic EL (Electro-Luminescence) display; an audio output device such as a speaker or headphones; or a printer device. The output device 917 outputs the result obtained through the processing of the information processing device 900 as text or video such as an image or as sound such as voice or audio. [0116] The storage device 919 is a device for storing data, constructed as an example of a storage unit of the information processing device 900. The storage device 919 includes, for example, a magnetic storage device such as HDD (Hard Disk Drive), a semi conductor storage device, an optical storage device, or a magneto-optical storage device. This storage device 929 includes, for example, programs or various data executed by the CPU 901 or various data acquired from the outside. [0117] The drive 921 is a reader/writer for a removable recording medium 927 such as a magnetic disk, an optical disc, a magneto-optical disk, or semiconductor memory, and is incorporated in or externally attached to the information processing device 900. The drive 921 reads information recorded on a removable recording medium 927 that is mounted, and outputs the information to the RAM 905. The drive 921 also writes in formation to the removable recording medium 927 that is mounted. [0118] The connection port 923 is a port for directly connecting a device to the information processing device 900. The connection port 923 can be, for example, a USB (Universal Serial Bus) port, an IEEE 1394 port, or a SCSI (Small Computer System Interface) port. In addition, the connection port 923 may be an RS-232 port, an optical audio terminal, or a HDMI (High-Definition Multimedia Interface) port. When the external connection device 929 is connected to the connection port 923, the information processing device 900 and the external connection device 929 can exchange various data. [01 19] The communication device 925 is, for example, a communication interface including a communication device or the like for connection to a communications network 931. The communication device 925 can be, for example, a wired or wireless LAN (Local Area Network) or a communication card for Bluetooth (registered trademark) or WUSB (Wireless USB). Alternatively, the communication device 925 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various communication. The communication device 925 transmits or receives signals or the like via the Internet or to/from other communication devices, for example, using a predetermined protocol such as TCP/IP. In addition, the commu nications network 931 connected to the communication device 925 is a network connected by wire or wirelessly, and is, for example, the Internet, a home LAN, infrared communication, radio wave communication, or satellite communication. [0120] The image pickup device 933 is, for example, an apparatus which captures a real world and generates a captured image by using image sensor such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) and various components such as lens for picking up a subject image to the image sensor. The image device 933 may be configured to pick up still images or moving images. [0121] The sensor 935 may be various types of sensors such as an acceleration sensor, a gyro sensor, a geomagnetic sensor, an optical sensor, and an acoustic sensor. The sensor 935 acquires information related to the state of an information processing apparatus 900 such as the shape of housing of the information processing apparatus 900 and information related to surrounding environment of the information processing apparatus 900 such as brightness or noise in surroundings of the information processing apparatus 900. Moreover, the sensor 935 may include a GPS (Global Po sitioning System) sensor which receives a GPS signal and measures latitude, longitude and altitude of the apparatus. [0122] An example of the hardware configuration of the information processing apparatus 900 has been described. The respective components described above may be configured using general purpose elements, and may be configured by hardware spe cialized to the function of the respective components. Such configurations can be ap propriately changed according to the technical level at the time of implementing the present embodiments. [0123] Although preferred embodiments of the present disclosure are described in detail above with reference to the appended drawings, the disclosure is not limited thereto. It should be understood by those skilled in the art that various modifications, com binations, sub-combinations and alterations may occur depending on design re quirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof. [0124] Additionally, the following configurations are also within the technical scope of the present disclosure. (1) An apparatus including: an image processor configured to receive a video including an object, determine a positional relationship between the apparatus and the object, change a positional relationship between an image superimposed on the video and the object when the positional relationship between the apparatus and the object changes. (2) The apparatus according to (1), wherein the image processor determines an angle between a direction of the object and a direction of the apparatus and changes the p o sitional relationship between the image superimposed on the video and the object based on the angle. (3) The apparatus according to (2), wherein the image processor determines that the positional relationship between the image superimposed on the video and the object is a front view relationship when the angle is below a first threshold angle. (4) The apparatus according to (3), wherein the image processor changes the p o sitional relationship between the image superimposed on the video and the object from the front view relationship to an oblique view relationship when the angle exceeds the first threshold angle. (5) The apparatus according to (4), wherein the image processor changes the positional relationship between the image superimposed on the video and the object from the oblique relationship to the front view relationship when the angle drops below a second threshold angle. (6) The apparatus according to (5), wherein the second threshold angle is lower than the first threshold angle. (7) The apparatus according to (4), wherein the image processor superimposes the image on the video in a plane of the object for the front view relationship and su perimposes the image on the video above the object for the oblique view relationship. (8) The apparatus according to (1) to (7), wherein the image processor superimposes a text message on the video with the image. (9) The apparatus according to (8), wherein the image processor superimposes a text message on the video with the image when the image is modified to fit on a display screen. (10) The apparatus according to (9), wherein the image processor superimposes a text message providing instructions to eliminate modification of the image to fit on the display screen. (11) The apparatus according to (1), wherein the image processor determines a distance between the object and the apparatus and changes the positional relationship between the image superimposed on the video and the object based on the distance. (12) The apparatus according to ( 11), wherein the image processor changes the image superimposed on the video based on the distance. (13) The apparatus according to (12), wherein the image processor changes the image superimposed on the video based on the distance such that additional detail is displayed when the distance is less than a first threshold distance. (14) The apparatus according to (13), wherein the image processor changes the image superimposed on the video based on the distance such that additional detail is removed when the distance exceeds a second threshold distance. (15) The apparatus according to (14), wherein the second threshold distance is shorter than the first threshold distance. (16) The apparatus according to (1) to (15), further comprising: a receiver configured to receive the image from an external device. (17) The apparatus according to (1) to (16), further comprising: a display configured to display the image superimposed on the video. (18) The apparatus according to (1) to (17), further comprising: a sensor configured measure positional information of the apparatus. (19) A method including: receiving a video including an object, determining a positional relationship between the apparatus and the object, changing a positional relationship between an image superimposed on the video and the object when the positional relationship between the apparatus and the object changes. (20) A non-transitory computer readable medium encoded with a program that, when loaded on a processor, causes the processor to perform a method including: receiving a video including an object, determining a positional relationship between the apparatus and the object, changing a positional relationship between an image superimposed on the video and the object when the positional relationship between the apparatus and the object changes. Reference Signs List 100, 200, 300 Information processing apparatus 102 Image pickup unit 104 Image recognition unit 108 Positional relationship detection unit 110 Selection unit 114 Display target information output unit 116 Message information output unit 118 Display control unit 120 Display unit 222 Sensor unit 324 Communication unit obj_r Real object obj_v Virtual object PCT7JP2012/005904 Claims [Claims 1] An apparatus comprising: an image processor configured to receive a video including an object, determine a positional relationship between the apparatus and the object, change a positional relationship between an image superimposed on the video and the object when the positional relationship between the apparatus and the object changes. [Claims 2] The apparatus according to claim 1, wherein the image processor de termines an angle between a direction of the object and a direction of the apparatus and changes the positional relationship between the image superimposed on the video and the object based on the angle. [Claims 3] The apparatus according to claim 2, wherein the image processor de termines that the positional relationship between the image su perimposed on the video and the object is a front view relationship when the angle is below a first threshold angle. [Claims 4] The apparatus according to claim 3, wherein the image processor changes the positional relationship between the image superimposed on the video and the object from the front view relationship to an oblique view relationship when the angle exceeds the first threshold angle. [Claims 5] The apparatus according to claim 4, wherein the image processor changes the positional relationship between the image superimposed on the video and the object from the oblique relationship to the front view relationship when the angle drops below a second threshold angle. [Claims 6] The apparatus according to claim 5, wherein the second threshold angle is lower than the first threshold angle. [Claims 7] The apparatus according to claim 4, wherein the image processor su perimposes the image on the video in a plane of the object for the front view relationship and superimposes the image on the video above the object for the oblique view relationship. [Claims 8] The apparatus according to claim 1, wherein the image processor su perimposes a text message on the video with the image. [Claims 9] The apparatus according to claim 8, wherein the image processor su perimposes a text message on the video with the image when the image is modified to fit on a display screen. [Claims 10] The apparatus according to claim 9, wherein the image processor superimposes a text message providing instructions to eliminate modi fication of the image to fit on the display screen. [Claims 11] The apparatus according to claim 1, wherein the image processor de termines a distance between the object and the apparatus and changes the positional relationship between the image superimposed on the video and the object based on the distance. [Claims 12] The apparatus according to claim 11, wherein the image processor changes the image superimposed on the video based on the distance. [Claims 13] The apparatus according to claim 12, wherein the image processor changes the image superimposed on the video based on the distance such that additional detail is displayed when the distance is less than a first threshold distance. [Claims 14] The apparatus according to claim 13, wherein the image processor changes the image superimposed on the video based on the distance such that additional detail is removed when the distance exceeds a second threshold distance. [Claims 15] The apparatus according to claim 14, wherein the second threshold distance is shorter than the first threshold distance. [Claims 16] The apparatus according to claim 1, further comprising: a receiver configured to receive the image from an external device. [Claims 17] The apparatus according to claim 1, further comprising: a display configured to display the image superimposed on the video. [Claims 18] The apparatus according to claim 1, further comprising: a sensor configured measure positional information of the apparatus. [Claims 19] A method comprising: receiving a video including an object, determining a positional relationship between the apparatus and the object, changing a positional relationship between an image superimposed on the video and the object when the positional relationship between the apparatus and the object changes. [Claims 20] A non-transitory computer readable medium encoded with a program that, when loaded on a processor, causes the processor to perform a method comprising: receiving a video including an object, determining a positional relationship between the apparatus and the object, changing a positional relationship between an image superimposed on PCT/JP2012/005904 the video and the object when the positional relationship between the apparatus and the object changes.