Patent Publication Number: US-9407898-B2

Title: Display control device, display control method, and program

Description:
BACKGROUND 
     The present disclosure relates to a display control device, a display control method, and a program. 
     A display control device for stereoscopically displaying an object has been known for a while. The display control device first calculates display positions, on a display screen, of an object image for a right eye to be viewed only by a right eye of a viewer and an object image for a left eye to be viewed only by a left eye of the viewer by performing perspective transformation as described in JP H6-4683A on three-dimensional coordinates set for an object. Then, the display control device corrects the calculated display positions and a scale set for the object (width and height of the object). Then, the display control device displays the object image for a right eye and the object image for a left eye at the corrected display positions at a corrected scale. The display control device thereby stereoscopically displays the object. 
     SUMMARY 
     In this manner, the display control device has to perform may processes to stereoscopically display an object. Accordingly, technologies of the past had an issue that stereoscopic display of an object was possibly delayed in a case the display control device did not possess hardware dedicated to stereoscopic display of an object. As a case the display control device does not possess hardware dedicated to stereoscopic display of an object, a case where the display control device is a small device, such as a mobile phone, is conceivable, for example. 
     In light of the foregoing, it is desirable to provide a display control device, a display control method and a program which are novel and improved, and which are capable of stereoscopically displaying an object more swiftly than in the past even when hardware dedicated to stereoscopic display of an object is not included. 
     According to an embodiment of the present disclosure, there is provided a display control device which includes an information acquisition unit for acquiring information related to an object image for a right eye to be observed by a right eye of a viewer and an object image for a left eye to be observed by a left eye of the viewer, a determination unit for determining whether scale correction of the information acquired by the information acquisition unit can be omitted, and a display control unit for performing control of stereoscopically displaying an object based on the information acquired by the information acquisition unit, in a case it is determined that the scale correction can be omitted. 
     The determination unit may determine that the scale correction can be omitted, in a case a value obtained by dividing an amount of change that is an amount by which a scale after the scale correction had changed relative to the scale before the scale correction by the scale before the scale correction is within an allowable range. 
     The determination unit may determine that the scale correction can be omitted, in a case a following formula (1) is satisfied. 
     
       
         
           
             
               
                 
                   
                     
                       - 
                       
                         e 
                         
                           1 
                           - 
                           e 
                         
                       
                     
                     ⁢ 
                     
                       f 
                       d 
                     
                   
                   &lt; 
                   
                     Δ 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     z 
                   
                   &lt; 
                   
                     
                       e 
                       
                         1 
                         + 
                         e 
                       
                     
                     ⁢ 
                     
                       f 
                       d 
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     The Δz is a relative display position of a stereoscopically displayed objet image to a display screen on which the object image for a right eye and the object image for a left eye are displayed, the e is a boundary value of the allowable range, and the f d  is a distance to the display screen from the right eye or the left eye of the viewer. 
     According to another embodiment of the present disclosure, there is provided a display control device which includes an information acquisition unit for acquiring information related to an object image for a right eye to be observed by a right eye of a viewer and an object image for a left eye to be observed by a left eye of the viewer, an information adjustment unit for adjusting the information acquired by the information acquisition unit to information for which scale correction can be omitted, and a display control unit for performing control of stereoscopically displaying an object, based on the information adjusted by the information adjustment unit. 
     The information adjustment unit may adjust the information acquired by the information acquisition unit in such a way that a value obtained by dividing an amount of change that is an amount by which a scale after the scale correction had changed relative to the scale before the scale correction by the scale before the scale correction falls within an allowable range. 
     The information adjustment unit may adjust the information acquired by the information acquisition unit in such a way that a following formula (1) is satisfied. 
     
       
         
           
             
               
                 
                   
                     
                       - 
                       
                         e 
                         
                           1 
                           - 
                           e 
                         
                       
                     
                     ⁢ 
                     
                       f 
                       d 
                     
                   
                   &lt; 
                   
                     Δ 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     z 
                   
                   &lt; 
                   
                     
                       e 
                       
                         1 
                         + 
                         e 
                       
                     
                     ⁢ 
                     
                       f 
                       d 
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     The Δz is a relative display position of a stereoscopically displayed objet image to a display screen on which the object image for a right eye and the object image for a left eye are displayed, the e is a boundary value of the allowable range, and the f d  is a distance to the display screen from the right eye or the left eye of the viewer. 
     According to another embodiment of the present disclosure, there is provided a display control method which includes acquiring information related to an object image for a right eye to be observed by a right eye of a viewer and an object image for a left eye to be observed by a left eye of the viewer, determining whether scale correction of the acquired information can be omitted, and performing control of stereoscopically displaying an object based on the acquired information, in a case it is determined that the scale correction can be omitted. 
     According to another embodiment of the present disclosure, there is provided a display control method which includes acquiring information related to an object image for a right eye to be observed by a right eye of a viewer and an object image for a left eye to be observed by a left eye of the viewer, adjusting the acquired information to information for which scale correction can be omitted, and performing control of stereoscopically displaying an object, based on the adjusted information. 
     According to another embodiment of the present disclosure, there is provided a program for causing a computer to realize an information acquisition function of acquiring information related to an object image for a right eye to be observed by a right eye of a viewer and an object image for a left eye to be observed by a left eye of the viewer, a determination function of determining whether scale correction of the information acquired by the information acquisition function can be omitted, and a display control function of performing control of stereoscopically displaying an object based on the information acquired by the information acquisition function, in a case it is determined that the scale correction can be omitted. 
     According to another embodiment of the present disclosure, there is provided a program for causing a computer to realize an information acquisition function of acquiring information related to an object image for a right eye to be observed by a right eye of a viewer and an object image for a left eye to be observed by a left eye of the viewer, an information adjustment function of adjusting the information acquired by the information acquisition function to information for which scale correction can be omitted, and a display control function of performing control of stereoscopically displaying an object, based on the information adjusted by the information adjustment function. 
     According to the embodiments of the present disclosure described above, it is possible to stereoscopically display an object more swiftly than in the past even when hardware dedicated to stereoscopic display of an object is not included. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a configuration of a display control device according to a first embodiment of the present disclosure; 
         FIG. 2  is an explanatory diagram for describing each parameter of a perspective transformation matrix; 
         FIG. 3  is a flow chart showing steps of a process of the display control device according to the first embodiment; 
         FIG. 4  is a block diagram showing a configuration of a display control device according to a second embodiment of the present disclosure; 
         FIG. 5  is a block diagram showing a configuration of a display control device according to a third embodiment of the present disclosure; 
         FIG. 6  is an explanatory diagram showing a state where information is being adjusted; 
         FIG. 7  is a flow chart showing steps of a process of the display control device according to the third embodiment of the present disclosure; 
         FIG. 8  is a block diagram showing a configuration of a display control device according to a fourth embodiment of the present disclosure; and 
         FIG. 9  is a block diagram showing an example of a hardware configuration of a display control device. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     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 configuration are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. 
     Additionally, an explanation wilt be given in the following order. 
     1. First Embodiment (Example of Using Information Related to Object Image for Right Eye and Object Image for Left Eye Without Correcting the Information in a Case Correction of the Information is Unnecessary) 
     2. Second Embodiment (Example of Acquiring, in First Embodiment, Information Related to Object Image for Right Eye and Object Image for Left Eye from Outside Display Control Device) 
     3. Third Embodiment (Example of Adjusting Information Related to Object Image for Right Eye and Object Image for Left Eye to Information for which Correction can be Omitted) 
     4. Fourth Embodiment (Example of Acquiring, in Third Embodiment, Information Related to Object Image for Right Eye and Object Image for Left Eye from Outside Display Control Device) 
     5. Hardware Configuration 
     Additionally, in the present disclosure, “stereoscopic display” means display that allows stereoscopic viewing by a viewer. 
     1. First Embodiment 
     [Configuration of Display Control Device  10 ] 
     First, a configuration of a display control device  10  will be described based on  FIGS. 1 and 2 . The display control device  10  includes a storage unit  11 , a display position calculation unit  12 , an operation unit  13 , a determination unit  14 , a display control unit  15 , a display unit  17 , and an information acquisition unit  18 . The display control unit  15  includes a normal display control unit  15 A, and a simple display control unit  15 B. 
     The storage unit  11  stores image information including three-dimensional coordinates and scales (widths and heights) of various objects, positions of points of view (right eye and left eye) of a viewer, a position of a display screen  19  of the display unit  17  (see  FIG. 2 ), and the like. The three-dimensional coordinates indicate a position at which an object is to be stereoscopically displayed. For example, a z-axis is an axis perpendicular to the display screen  19 , and indicates depth. The positive direction of the z-axis is a direction from the display screen  19  towards a viewer. An x-axis is an axis parallel to a long side of the display screen  19 , and a y-axis is an axis parallel to a short side of the display screen  19 . The position of an origin is arbitrary, but is at a centre point C of the display screen  19 , for example. The width of an object is the length in the x-axis direction, and the height of the object is the length in the y-axis direction. The three-dimensional coordinates of the object is given for each vertex of the object. For example, in a case the object is a rectangle, the three-dimensional coordinates are given for each of the four vertices of the rectangle. 
     The display position calculation unit  12  (information acquisition unit) acquires the image information from the storage unit  11 , and, based on the acquired information, generates an object image for a right eye and an object image for a left eye and, also, calculates display positions of the object image for a right eye and the object image for a left eye on the display screen  19 . Additionally, the object image for a right eye is an image to be observed only by a right eye of the viewer, and the object image for a left eye is an image to be observed only by a left eye of the viewer. 
     Specifically, the display position calculation unit  12  multiplies four-dimensional coordinates (x, y, z, 1), which is obtained by adding a dimension to the three-dimensional coordinates of the object, by a perspective transformation matrix expressed by the following formula (2), and takes the obtained x-coordinate and y-coordinate as the display position of the object image for a right eye on the display screen  19 . In a case there are multiple vertices in the object, the display position calculation unit  12  calculates the display position for each vertex. The display position of each vertex of the object image for a right eye is calculated in this manner. The display position calculation unit  12  calculates the display position of the object image for a left eye on the display screen  19  by the same process (that is, based on the four-dimensional coordinates (x, y, z, 1), which is obtained by adding a dimension to the three-dimensional coordinates of the object, and the following formula (2)). 
     
       
         
           
             
               
                 
                   
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                               H 
                             
                           
                         
                         
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                           0 
                         
                         
                           
                             
                               - 
                               
                                 ( 
                                 
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                                   + 
                                   n 
                                 
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                               ( 
                               
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                               2 
                             
                             ⁢ 
                             
                               fn 
                               / 
                               
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                     ) 
                   
                     
                 
               
               
                 
                   ( 
                   2 
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     Here, each parameter used for the perspective transformation matrix will be described based on  FIG. 2 .  FIG. 2  shows a state where a right eye RE and a left eye LE of a viewer are observing the display screen  19 . A field of view R 1  of the right eye RE and a field of view L 1  of the left eye LE reach over the entire display screen  19 . An object is displayed between a near plane  200  and a far plane  300 . As shown in  FIG. 2 , f d  is the distance to the display screen  19  from the right eye RE or the left eye LE, and W is the width of the display screen  19 . H is the height of the display screen  19 , and p d  is the distance from the right eye RE to the left eye LE. f is the distance to the far plane  300  from the right eye RE or the left eye LE, and n is the distance to the near plane  200  from the right eye RE of the left eye LE. 
     The display position calculation unit  12  outputs to the information acquisition unit  18  information including the generated object image for a right eye and object image for a left eye, their calculated display positions, and the image information acquired from the storage unit  11 . The information acquisition unit  18  outputs the acquired information to the determination unit  14 . 
     The operation unit  13  allows input operation by a viewer, and, according to the input operation, generates information for specifying contents of control and outputs the same to the determination unit  14 . 
     The determination unit  14  determines, base on the information provided by the display position calculation unit  12 , whether correction of the information (scale correction) can be omitted. That is, the determination unit  14  determines whether correction of the display positions of the object image for a right eye and the object image for a left eye on the display screen  19  and the scale of the object, that is, the scale of the object image for a right eye and the object image for a left eye, can be omitted. Additionally, in the case there are multiple vertices in the object, the determination unit  14  may perform the determination for all the vertices, or may extract a vertex or multiple vertices as representative points and perform the determination for the representative points. Also, correction of the display positions and the scale means multiplication of each of x-coordinates, y-coordinates, heights and widths of the object image for a right eye and the object image for a left eye by a value expressed by the following formula (3). 
     
       
         
           
             
               
                 
                   
                     f 
                     d 
                   
                   
                     
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                       d 
                     
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                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       z 
                     
                   
                 
               
               
                 
                   ( 
                   3 
                   ) 
                 
               
             
           
         
       
     
     More particularly, the determination unit  14  takes the larger of the scale, that is, the height or the width, of the object as the representative scale. Then, the determination unit  14  determines that correction can be omitted in a case the value obtained by dividing the amount of change, which is the amount by which the representative scale after correction had changed relative to the representative scale before correction, by the representative scale before correction is within an allowable range. 
     More particularly, the determination unit  14  determines that correction can be omitted in a case the following formula (4) is satisfied (in a case where f d &gt;&gt;Δz). 
     
       
         
           
             
               
                 
                   
                     
                       - 
                       
                         e 
                         
                           1 
                           - 
                           e 
                         
                       
                     
                     ⁢ 
                     
                       f 
                       d 
                     
                   
                   &lt; 
                   
                     Δ 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     z 
                   
                   &lt; 
                   
                     
                       e 
                       
                         1 
                         + 
                         e 
                       
                     
                     ⁢ 
                     
                       f 
                       d 
                     
                   
                 
               
               
                 
                   ( 
                   4 
                   ) 
                 
               
             
           
         
       
     
     Δz is the z-coordinate of the object that is stereoscopically displayed (that is, it is a relative display position of the stereoscopically displayed object image to the display screen  19 ). e is a value indicating the upper limit of the allowable range mentioned above, and f d  is the distance to the display screen  19  from the right eye RE or the left eye LE of the viewer. 
     A derivation process of the above formula (4) will be described here. 
     When taking the representative scale before correction as L and the representative scale after correction as L′, the representative scale after correction L′ is expressed by the following formula (4-1). 
     
       
         
           
             
               
                 
                   
                     L 
                     ′ 
                   
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                           ⁢ 
                           
                               
                           
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                     L 
                   
                 
               
               
                 
                   ( 
                   
                     4 
                     ⁢ 
                     
                       - 
                     
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                     1 
                   
                   ) 
                 
               
             
           
         
       
     
     Accordingly, the value obtained by dividing the amount of change by the representative scale before correction L will be expressed by the following formula (5). 
     
       
         
           
             
               
                 
                   
                     
                        
                       
                         
                           L 
                           ′ 
                         
                         - 
                         L 
                       
                        
                     
                     L 
                   
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                   ( 
                   5 
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     For this value to be within the allowable range, the following formula (6) has to be satisfied. 
     
       
         
           
             
               
                 
                   
                      
                     
                       
                         Δ 
                         ⁢ 
                         
                             
                         
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                         z 
                       
                       
                         
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     Here, since f d  is the distance to the display screen  19  from the right eye RE or the left eye LE of the viewer, f d &gt;Δz is established. Therefore, formula (6) is developed as follows. 
     
       
         
           
             
               
                 
                   
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     Accordingly, formula (4) is derived from that “the value obtained by dividing the amount of change, which is the amount by which the representative scale after correction had changed relative to the representative scale before correction, by the representative scale before correction is within the allowable range.” 
     Here, since the difference between the scale of an object that is stereoscopically displayed in a case correction is omitted and the scale of an object that is stereoscopically displayed in a case correction is performed will be smaller as the upper limit value (boundary value) e of the allowable range is lower, it is preferable, from the standpoint of reducing an odd feeling experienced by a viewer, that the upper limit value is small. This is because one purpose of performing correction is to reduce the difference between the scale of a stereoscopically displayed object and the actual scale of the object. However, if the upper limit value e is too small, the amount of information for which correction is omitted becomes small, and the process of stereoscopic display will be delayed. Thus, the upper limit value e of the allowable range is determined in view of such circumstances and will be, for example, 0.05 (=5%). 
     For example, a viewer is assumed to view a display screen  19  whose pixel density is 50 ppi (pixel per inch) and resolution in the x-axis direction is 1920 pixels from a distance of 120 inches (about 3 m). 
     In this case, f d  will be 120 inches×50 ppi=6000 pixels. Accordingly, when e=0.05, formula (4) will be −315 pixels&lt;Δz&lt;285 pixels, and, thus, correction can be omitted if the popping out (forward stereoscopic display) or going in (backward stereoscopic display) is within the range of about 5.7 inches (about 15 cm). 
     In the case it is determined that correction can be omitted, the determination unit  14  outputs the information provided by the display position calculation unit  12  to the simple display control unit  15 B. On the other hand, in the case it is not determined that correction can be omitted, the determination unit  14  outputs the information provided by the display position calculation unit  12  to the normal display control unit  15 A. 
     Additionally, in the case determination is performed for multiple vertices, the determination unit  14  may output the information provided by the display position calculation unit  12  to the simple display control unit  15 B if formula (4) is satisfied for all the vertices for which determination has been performed, and, if otherwise, may output the information provided by the display position calculation unit  12  to the normal display control unit  15 A. Also, the determination unit  14  may take one or more vertices, among the vertices for which determination has been performed, as representative points, and may output the information provided by the display position calculation unit  12  to the simple display control unit  15 B if formula (4) is satisfied for all the representative points, and, if otherwise, may output the information provided by the display position calculation unit  12  to the normal display control unit  15 A. 
     Also, in the case information specifying simple display control is provided by the operation unit  13 , the determination unit  14  outputs the information provided by the display position calculation unit  12  to the simple display control unit  15 B. On the other hand, in the case information specifying normal display control is provided by the operation unit  13 , the determination unit  14  outputs the information provided by the display position calculation unit  12  to the normal display control unit  15 A. 
     The normal display control unit  15 A performs control of correcting the information provided by the determination unit  14 , and of causing, based on the information after correction, the object image for a right eye to be observed only by the right eye RE of the viewer and the object image for a left eye to be observed only by the left eye LE of the viewer. The normal display control unit  15 A thereby performs the control of stereoscopically displaying the object. 
     More particularly, the normal display control unit  15 A corrects the display position of the object image for a right eye by multiplying the x-coordinate and the y-coordinate of each vertex of the object image for a right eye by the above formula (3). Furthermore, the normal display control unit  15 A takes the height and width of the object as the height and width of the object image for a right eye, and corrects the scale of the object image for a right eye by multiplying each of the height and width by the value of the above formula (3). Then, the normal display control unit  15 A performs control of displaying the object image for a right eye at the display position after correction and at the scale after correction. The normal display control unit  15 A performs the same process also for the object image for a left eye. Additionally, the method of stereoscopically displaying the object may be any method such as an active shutter method, a patterning method, a parallax barrier method, a lenticular method, or the like. 
     The simple display control unit  15 B (display control unit) performs the control of causing the object image for a right eye to be observed only by the right eye RE of the viewer and the object image for a left eye to be observed only by the left eye LE of the viewer, based on the information provided by the determination unit  14 . The normal display control unit  15 A thereby performs the control of stereoscopically displaying the object. That is, the simple display control unit  15 B performs control of stereoscopically displaying the object by using the information provided by the determination unit  14  as it is without correcting the same. 
     More particularly, the simple display control unit  15 B takes the scale of the object as the scale of the object image for a right eye. Then, the simple display control unit  15 B performs control of displaying the object image for a right eye at the display position calculated by the display position calculation unit  12  and at the scale described above. The simple display control unit  15 B performs the same process also for the object image for a left eye. Additionally, the method of stereoscopically displaying the object may be any method such as an active shutter method, a patterning method, a parallax barrier method, a lenticular method, or the like. 
     The display unit  17  displays the object image for a left eye and the object image for a right eye on the display screen  19  by the control by the normal display control unit  15 A or the simple display control unit  15 B. 
     [Steps of Process of Display Control Device] 
     Next, steps of a process of the display control device  10  will be described along the flow chart shown in  FIG. 3 . 
     In step S 1 , the display position calculation unit  12  acquires image information from the storage unit  11 , and, based on the acquired information, generates an object image for a right eye and an object image for a left eye and, also, calculates the display positions of the object image for a right eye and the object image for a left eye on the display screen  19 . The display position calculation unit  12  outputs, to the information acquisition unit  18 , information including the generated object image for a right eye and object image for a left eye, their calculated display positions, and the image information acquired from the storage unit  11 . The information acquisition unit  18  outputs the acquired information to the determination unit  14 . 
     In step S 2 , the determination unit  14  determines whether a condition that information specifying normal display control is provided by the operation unit  13  is satisfied, and, in the case it is determined that this condition is satisfied, outputs the information provided by the display position calculation unit  12  to the normal display control unit  15 A and proceeds to step S 6 . On the other hand, in the case it is not determined that this condition is satisfied, the determination unit  14  proceeds to step S 3 . 
     In step S 3 , the determination unit  14  determines whether a condition that information specifying simple display control is provided by the operation unit  13  is satisfied, and, in the case it is determined that this condition is satisfied, outputs the information provided by the display position calculation unit  12  to the simple display control unit  15 B and proceeds to step S 5 . On the other hand, in the case it is not determined that this condition is satisfied, the determination unit  14  proceeds to step S 4 . 
     In step S 4 , the determination unit  14  determines, based on the information provided by the display position calculation unit  12 , whether correction of the information can be omitted, i.e. whether the above formula (4) is satisfied. The determination unit  14  proceeds to step S 5  in the case it is determined that the above formula (4) is satisfied, and proceeds to step S 6  in the case it is not determined that formula (4) is satisfied. 
     In step S 5 , the simple display control unit  15 B performs control of causing the object image for a right eye to be observed only by the right eye RE of the viewer and the object image for a left eye to be observed only by the left eye LE of the viewer, based on the information provided by the determination unit  14 . The simple display control unit  15 B thereby performs the control of stereoscopically displaying the object. That is, the simple display control unit  15 B performs control of stereoscopically displaying the object by using the information provided by the determination unit  14  as it is without correcting the same. 
     In step S 6 , the normal display control unit  15 A corrects the information provided by the determination unit  14 , and, based on the corrected information, performs control of causing the object image for a right eye to be observed by only the right eye RE of the viewer and the object image for a left eye to be observed by only the left eye LE of the viewer. The normal display control unit  15 A thereby performs the control of stereoscopically displaying the object. 
     According to the first embodiment, the display control device  10  simplifies, in the above manner, the process necessary to stereoscopically display an object by omitting the correction process in a case a predetermined condition is satisfied. This enables the display control device  10  to perform stereoscopic display of an object more swiftly than in the past even when hardware dedicated to stereoscopic display of an object is not included. 
     Also, in the past, the scale of the object image for a right eye and the object image for a left eye was corrected even in a case where correction could be omitted, that is, even if the change in the display position and the scale caused by correction was small. Accordingly, it was possible that image quality was degraded due to the correction. The display control device  10 , however, can prevent such degradation in image quality by omitting the correction. 
     2. Second Embodiment 
     Next, a second embodiment will be described. Only the parts different from the first embodiment will be described for the second embodiment and each embodiment described later. 
     [Configuration of Display Control Device  20 ] 
       FIG. 4  is a block diagram showing a configuration of a display control device  20  according to a second embodiment. The display control device  20  is the display control device  10  without the display position calculation unit  12  and the storage unit  11 . Additionally, the information acquisition unit  18  is wire-connected or wirelessly connected to an external storage device  100 . 
     The storage device  100  stores the object image for a right eye and the object image for a left eye, their display positions and scale before correction, and the image information stored in the storage unit  11  of the first embodiment. 
     The information acquisition unit  18  acquires the information described above from the storage device  100 , and outputs the same to the determination unit  14 . The following processing is the same as that of the first embodiment. 
     In the second embodiment, the display control device  20  does not have to calculate the display positions of the object image for a right eye and the object image for a left eye, and, thus, the process necessary for stereoscopic display of an object is more simplified than the first embodiment. Additionally, the second embodiment assumes a case where the display control device  20  is a small device and a small storage device  100  is inserted in this device, for example. This also applies to a fourth embodiment below. 
     3. Third Embodiment 
     Next, a third embodiment will be described.  FIG. 5  is a block diagram showing a configuration of a display control device  30  according to the third embodiment. The display control device  30  includes a storage unit  21 , a display position calculation unit  22 , a determination unit  23 , an information adjustment unit  24 , a display control unit  25 , a display unit  26 , and an information acquisition unit  28 . 
     The storage unit  21  stores the same information as the storage unit  11 . The display position calculation unit  22  performs the same process as the display position calculation unit  12 , and outputs information acquired by the process to the information acquisition unit  28 . The information acquisition unit  28  outputs the acquired information to the determination unit  23 . 
     The determination unit  23  determines whether the above formula (4) is satisfied, based on the information provided by the display position calculation unit  22 , and, outputs the information provided by the display position calculation unit  22  to the display control unit  25  in the case it is determined that the formula is satisfied, and outputs the information provided by the display position calculation unit  22  to the information adjustment unit  24  in the case it is not determined that the formula is satisfied. Additionally, in the case there are multiple vertices, the determination unit  23  determines whether formula (4) is satisfied for all the vertices, and, in the case it is determined that the formula is satisfied, the determination unit  23  may output the information provided by the display position calculation unit  22  to the display control unit  25 , and, if otherwise, it may output the information provided by the display position calculation unit  22  to the information adjustment unit  24 . Also, in the case there are multiple vertices, the determination unit  23  may select one or more vertices as representative points. Then, the determination unit  23  determines whether formula (4) is satisfied for all the representative points, and, in the case it is determined that the formula is satisfied, the determination unit  23  may output the information provided by the display position calculation unit  22  to the display control unit  25 , and, if otherwise, it may output the information provided by the display position calculation unit  22  to the information adjustment unit  24 . 
     The information adjustment unit  24  adjusts the information provided by the determination unit  23  to information for which correction (scale correction) can be omitted. More particularly, the information adjustment unit  24  takes the larger of the scale of the object, that is, the height or the width, as a representative scale. Then, the information adjustment unit  24  adjusts the information provided by the determination unit  23  such that the value obtained by dividing the amount of change, which is the amount by which the representative scale after correction had changed relative to the representative scale before correction, by the representative scale before correction falls within an allowable range. 
     More particularly, the information adjustment unit  24  adjusts the z-coordinate of the object, that is, the display positions of the object image for a right eye and the object image for a left eye, in such a way that the above formula (4) is satisfied. That is, in the case the z-coordinate of the object is a positive value, the information adjustment unit  24  multiplies the z-coordinate of the object by a first coefficient, that is, a value obtained by dividing the right-hand side value of formula (4) by the z-coordinate of the near plane  200 . On the other hand, in the case the z-coordinate of the object is a negative value, the information adjustment unit  24  multiplies the z-coordinate of the object by a second coefficient, that is, a value obtained by dividing the left-hand side value of formula (4) by the z-coordinate of the far plane  300 . 
     Because adjustment is performed by the information adjustment unit  24 , the object is stereoscopically displayed at a position closer to a display screen  27  of the display unit  26 . This is shown in  FIG. 6 . As shown in  FIG. 6 , because adjustment is performed by the information adjustment unit  24 , objects  400  and  401  are stereoscopically displayed at positions nearer to the display screen  27 . That is, because adjustment is performed by the information adjustment unit  24 , the objects  400  and  401  are stereoscopically displayed within the ranges of point A and point B. Additionally, the point A is a point on the z-axis that takes the right-hand side value of formula (4) as the z-coordinate value, and the point B is a point on the z-axis that takes the left-hand side value of formula (4) as the z-coordinate value. In the case there are multiple vertices, the information adjustment unit  24  performs the adjustment for all the vertices. The information adjustment unit  24  outputs the information after adjustment to the display control unit  25 . 
     The display control unit  25  performs control of causing the object image for a right eye to be observed only by the right eye RE of the viewer and the object image for a left eye to be observed only by the left eye LE of the viewer, based on the information provided by the determination unit  23  or the information adjustment unit  24 . The display control unit  25  thereby performs control of stereoscopically displaying the object. 
     Particularly, the display control unit  25  performs control of displaying the object image for a right eye at the display position indicated by the information provided by the determination unit  23  or the information adjustment unit  24  at the scale indicated by the information provided by the determination unit  23  or the information adjustment unit  24 . The display control unit  25  performs the same process also for the object image for a left eye. Additionally, the method of stereoscopically displaying the object may be any method such as an active shutter method, a patterning method, a parallax barrier method, a lenticular method, or the like. 
     The display unit  26  displays the object image for a left eye and the object image for a right eye on the display screen  27  by the control by the display control unit  25 . 
     [Steps of Process of Display Control Device] 
     Next, steps of a process of the display control device  30  will be described along the flow chart shown in  FIG. 7 . 
     In step S 10 , the display position calculation unit  22  performs the same process as the display position calculation unit  12 , and outputs information acquired by the process to the information acquisition unit  28 . The information acquisition unit  28  outputs the acquired information to the determination unit  23 . 
     In step S 11 , the determination unit  23  determines whether adjustment of information is necessary. Specifically, the determination unit  23  determines whether the above formula (4) is satisfied, based on the information provided by the display position calculation unit  22 , and in the case it is determined that the formula is satisfied (in the case it is determined that adjustment is unnecessary), the determination unit  23  outputs the information provided by the display position calculation unit  22  to the display control unit  25  and proceeds to step S 13 , and in the case it is not determined that the formula is satisfied (in the case it is determined that adjustment is necessary), it outputs the information provided by the display position calculation unit  22  to the information adjustment unit  24 . 
     In step S 12 , the information adjustment unit  24  adjusts the information provided by the determination unit  23  to information for which correction can be omitted. Then, the information adjustment unit  24  outputs the information after adjustment to the display control unit  25 . 
     In step S 13 , the display control unit  25  performs control of causing the object image for a right eye to be observed only by the right eye RE of the viewer and the object image for a left eye to be observed only by the left eye LE of the viewer, based on the information provided by the determination unit  23  or the information adjustment unit  24 . The display control unit  25  thereby performs control of stereoscopically displaying the object. 
     According to the third embodiment, the display control device  30  adjusts, in the above manner, the information calculated by the display position calculation unit  22  to information for which correction can be omitted and stereoscopically displays an object based on this information, and, thus, the display control device  30  can simplify the process necessary to stereoscopically display an object. This enables the display control device  30  to perform stereoscopic display of an object more swiftly than in the past even when hardware dedicated to stereoscopic display of an object is not included. 
     4. Fourth Embodiment 
       FIG. 8  is a block diagram showing a configuration of a display control device  40  according to a fourth embodiment. The display control device  40  is the display control device  30  according to the third embodiment without the display position calculation unit  22  and the storage unit  21 . The information acquisition unit  28  is wire-connected or wirelessly connected to an external storage device  100 . 
     The storage device  100  stores the object image for a right eye and the object image for a left eye, their display positions and scale before correction, and the image information stored in the storage unit  11  of the first embodiment. 
     The information acquisition unit  28  acquires the information described above from the storage device  100 , and outputs the same to the determination unit  23 . The following processing is the same as that of the third embodiment. 
     According to the fourth embodiment, the display control device  40  does not have to calculate the display positions of the object image for a right eye and the object image of a left eye, and, thus, stereoscopic display of an object can be performed more swiftly than the third embodiment. 
     5. Hardware Configuration 
     Next, a hardware configuration of the display control devices  10  to  40  according to the embodiments of the present disclosure will be described in detail with reference to  FIG. 9 .  FIG. 9  is a block diagram for describing a hardware configuration of the display control devices  10  to  40  according to the embodiments of the present disclosure. 
     The display control devices  10  to  40  each mainly include a CPU  901 , a ROM  903 , and a RAM  905 . Furthermore, the display control devices  10  to  40  also include a host bus  907 , a bridge  909 , an external bus  911 , an interface  913 , an input unit  915 , an output unit  917 , a storage unit  919 , a drive  921 , a connection port  923 , and a communication unit  925 . 
     The CPU  901  functions as an arithmetic processing unit and a control unit, and controls entire operation or a part of the operation of the display control devices  10  to  40  according to various programs recorded on the ROM  903 , the RAM  905 , the storage unit  919 , or a removable recording medium  927 . The ROM  903  stores a program to be loaded on the CPU  901 , arithmetic parameters, or the like. The RAM  905  primarily stores a program to be loaded on the CPU  901 , parameters arbitrarily changed in execution of the program, or the like. These are connected to each other by the host bus  907  configured from an internal bus such as a CPU bus. 
     The host bus  907  is connected through the bridge  909  to the external bus  911  such as a PCI (Peripheral Component Interconnect/Interface) bus. 
     The input unit  915  is operation means operated by a user, such as a mouse, a keyboard, a touch panel, a button, a switch, or a lever, for example. Also, the input unit  915  may be remote control means that uses an infrared ray or other radio waves, or it may be an externally connected device  929  such as a mobile phone, a PDA or the like compatible with operation of the display control devices  10  to  40 , for example. Furthermore, the input unit  915  is configured from an input control circuit or the like that generates an input signal based on information input by a user using the operation means described above and that outputs the same to the CPU  901 . Users of the display control devices  10  to  40  can input various types of data to the display control devices  10  to  40  or issue a processing operation by operating this input unit  915 . 
     The output unit  917  is configured from a device capable of visually or auditorily notifying a user of acquired information. Such a device may be a display device such as a CRT display device, a liquid crystal display device, a plasma display device, an EL display device or a lamp, an audio output device such as speakers or headphones, a printer device, a mobile phone, a facsimile, or the like. The output device  917  outputs results obtained by various processes performed by the display control devices  10  to  40 , for example. Specifically, the display device displays, as text or image, results obtained by various processes performed by the display control devices  10  to  40 . For its part, the audio output device converts an audio signal formed from audio data, acoustic data or the like which has been reproduced into an analog signal and outputs the same. 
     The storage unit  919  is a device for storing data configured as an example of a storage unit of the display control devices  10  to  40 . The storage device  919  is configured from a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like, for example. This storage unit  919  stores a program to be loaded on the CPU  901 , various types of data, and acoustic signal data, image signal data or the like that is externally acquired. 
     The drive  921  is a reader/writer for a recording medium, and is embedded or externally attached to the display control devices  10  to  40 . The drive  921  reads information recorded on the attached removable recording medium  927  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and outputs the same to the RAM  905 . The drive  921  can also write a record on the attached removable recording medium  927  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. The removable recording medium  927  is a DVD medium, an HD-DVD medium, a Blu-ray medium, or the like, for example. The removable recording medium  927  may also be a CompactFlash (CF; registered trademark), a flash memory, a Secure Digital (SD) memory card, or the like. The removable recording medium  927  may also be an electronic appliance or an integrated circuit (IC) card on which a non-contact IC chip is mounted, or the like. 
     The connection port  923  is a port for directly connecting an appliance to the display control devices  10  to  40 . Examples of the connection port  923  include a Universal Serial Bus (USB) port, an IEEE1394 port, a Small Computer System Interface (SCSI) port, and the like. Other examples of the connection port  923  include an RS-232C port, an optical audio terminal, a High-Definition Multimedia Interface (HDMI) port, and the like. By connecting the externally connected device  929  to this connection port  923 , the display control devices  10  to  40  acquire acoustic signal data or image signal data directly from the externally connected device  929  or provide acoustic signal data or image signal data to the externally connected device  929 . 
     The communication unit  925  is a communication interface configured from a communication device or the like for connecting to a communication network  931 , for example. The communication unit  925  is a communication card for a wired or wireless Local Area Network (LAN), Bluetooth (registered trademark), a wireless USB (WUSB), or the like, for example. The communication unit  925  may also be an optical communication router, an Asymmetric Digital Subscriber Line (ADSL) router, a modem for various types of communication, or the like. This communication unit  925  can exchange signals or the like with the Internet or other communication appliances, for example, according to a predetermined protocol such as TCP/IP or the like. Also, the communication network  931  connected to the communication unit  925  is configured from a wire-connected or wirelessly connected network, or the like, and it may be the Internet, a home-use LAN, infrared communication, radio wave communication, satellite communication, or the like, for example. 
     In the foregoing, an example of the hardware configuration capable of realizing the functions of the display control devices  10  to  40  according to the embodiments of the present disclosure has been described. Each structural element described above may be configured from a general-purpose material or may be configured from hardware dedicated to the function of each structural element. Accordingly, hardware configuration to be used may be changed as appropriate according to the level of technology at the time of carrying out the embodiment. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof. 
     For example, in the second and fourth embodiments, the storage device  100  is assumed to be an external structure, but it may also be an internal structure. Furthermore, the simple display control unit  15 B may correct a part of the information provided by the determination unit  14 . For example, the simple display control unit  15 B may correct only the scale among the display positions and scale of the object image for a right eye and the object image for a left eye. Also in this case, the display control device  10  can perform stereoscopic display of the object more swiftly than in the past. 
     The present disclosure is applicable to a device for stereoscopically displaying an object. 
     The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2010-200153 filed in the Japan Patent Office on Sep. 7, 2010, the entire content of which is hereby incorporated by reference.