Computation time reduction for the three-dimensional displays

Abstract

A reconfigurable, three-dimensional display ( 1 ) wherein knowledge of the viewer's ( 4 ) eyes is used to enable the effective exit pupil(s) of the display system to be optimised. The system utilises this knowledge to identify contributing regions ( 5 ) within the display ( 1 ) that contribute light to the viewer ( 4 ). Priority is given to calculating and displaying the part of the display corresponding to the contributing region ( 5 ), thereby allowing the system computation requirements to be minimised. Further computation savings are achievable by recognising that only light travelling in a limited range of angles need to be considered.

The invention claimed is: 
     
       1. Apparatus for producing a three-dimensional image, said apparatus An apparatus comprising;: 
 a display means for producing a three dimensional image, said image capable of being configured to be viewed from a range of viewing positions, wherein said the display means having has an exit pupil of a size determined by values assigned to pixels in a plurality of sub-regions of the display means; 
 a monitoring means for determining a viewing position of at least one an observer,; and 
 control means, responsive to the monitoring means, for controlling the display means, wherein the control means provides computational priority to the determined viewing position by computing pixel values in the sub-regions such that a complete image is first provided for said the determined viewing position and, as a consequence, reducing the size of the exit pupil. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the viewing positions of two or more observers are determined and wherein priority is given to producing a complete image for each of the determined viewing positions. 
     
     
       3. The apparatus according to  claim 1  or  2 , wherein the control means identifies at least one a contributing region, comprising addressable sub-regions of the display means, that contributes to the image formed for the at least one viewing position and wherein priority is given to calculating pixel values of the display means for said at least one the contributing region. 
     
     
       4. The apparatus according to  claim 3 , wherein the control means gives priority to calculating pixel values for each of the sub-regions of the display means that comprise substantially the centre center of the at least one said contributing region. 
     
     
       5. The apparatus according to  claim 3  and, further comprising means for determining the position of ocular fixation within the display means of the at least one observer and, wherein the control means gives priority to calculating pixel values for each of the sub-regions of the display means that contribute substantially to the image at the position of ocular fixation of the at least one observer. 
     
     
       6. The apparatus according to any of the preceding claims claim 1, wherein the control means gives priority to calculating pixel values for each of the sub-regions of the display means that correspond substantially to parts of the image that are changing. 
     
     
       7. The apparatus according to  claim 1 , wherein the control means determines the a range of angles that sub-regions of the display means must direct light into to contribute to the image formed for the at least one viewing position, and wherein priority is given to calculating pixel values of the display means such that light is substantially directed into said the range of angles. 
     
     
       8. The apparatus according to  claim 1 , wherein the control means controls the display means such that the effective exit pupil of the apparatus is optimised optimized for the at least one viewer observer. 
     
     
       9. The apparatus according to  claim 1 , wherein the effective exit pupil over which the complete image is viewable is enlarged during periods when the image is substantially unchanging. 
     
     
       10. The apparatus according to  claim 1 , wherein the display means comprises a spatial light modulator (SLM) means. 
     
     
       11. The apparatus according to  claim 10 , wherein the control means calculates the modulation required in the sub-regions of the spatial light modulator means. 
     
     
       12. The apparatus according to  claim 1 , wherein the monitoring means collects information relating to the eyes of the at least one observer, and wherein said the information is used by the control means to adapt the effective exit pupil of the apparatus to match the eyes of the at least one observer. 
     
     
       13. The apparatus according to claim  1  3, wherein the addressable sub-regions of the display means display a computer generated hologram. 
     
     
       14. A method of, comprising: 
 reducing the a time required to display a reconfigurable three-dimensional image using a display means comprising a plurality of addressable sub-regions, capable of producing a configured to produce the three dimensional image which is capable of being viewed so as to be viewable from a range of viewing positions, a monitoring means for determining the viewing position of at least one observer, and control means responsive to the monitoring means for controlling the display means ( 1 ), wherein said method is comprised by the steps of:;  
 determining the a viewing position of the at least one an observer using a monitoring means; and 
 prioritising theresponsive to determining the viewing position of the observer, prioritizing control of the addressable sub-regions within the display means to first produce a complete image for the determined viewing position, thereby reducing the an initial computation of pixel values. 
 
     
     
       15. The method according to  claim 14 , wherein the viewing positions of two or more observers are determined, and wherein the control of the addressable sub-regions within the display means is prioritised prioritized to produce a the complete image for the two or more determined viewing positions of the two or more observers. 
     
     
       16. The method according to claims claim  14  or  15  and, further comprising the steps of: 
 identifying at least one a contributing region, comprising the addressable sub-regions of the display means, that contributes to the image formed for the at least one viewing position; and 
 giving priority to calculating pixel values for the sub-regions within the display means that comprise substantially the at least one said contributing region. 
 
     
     
       17. The method according to  claim 16 , wherein priority is given to calculating pixel values for each of the sub-regions of the display means that comprise substantially the centre center of the at least one said contributing region. 
     
     
       18. The method according to  claim 16 , further comprising the steps of: 
 determining the a position of ocular fixation of the observer within the display means of the at least one observer; and 
 giving priority to calculating pixel values for each of the sub-regions of the display means that contribute substantially to the image at the position of ocular fixation of the at least one observer. 
 
     
     
       19. The method according to  claim 14 , wherein priority is given to calculating pixel values for each of the sub-regions of the display means that correspond substantially to parts of the image that are changing. 
     
     
       20. The method according to  claim 14 , further comprising the steps of: 
 determining the a range of angles that sub-regions of the display means must direct light into to contribute substantially to the image formed for the at least one viewing position; and 
 calculating the pixel values of the display means such that priority is given to directing light into substantially said the range of angles. 
 
     
     
       21. The method according to  claim 14 , further comprising the step of controlling the display means such that the an effective exit pupil of the apparatus is optimised optimized for the at least one viewer observer. 
     
     
       22. The method according to  claim 14 , further comprising the step of enlarging the an effective exit pupil over which the complete image is viewable during periods when the image is substantially unchanging. 
     
     
       23. The method according to  claim 14 , wherein the display means comprises a spatial light modulator (SLM) means. 
     
     
       24. The method according to  claim 23 , wherein the control means calculates the an amount of modulation required in the sub-regions of the spatial light modulator means. 
     
     
       25. The method according to  claim 14 , wherein the monitoring means collects information relating to the eyes of the at least one observer, and wherein said the information is used by the control means to adapt the an effective exit pupil of the apparatus to match the one or more eyes of the at least one observer. 
     
     
       26. The method according to  claim 14 , wherein the addressable sub-regions of the display means display a computer generated hologram. 
     
     
       27. A system, comprising:
 a display configured to generate a three-dimensional image, wherein the display is comprised of a plurality of sub-regions;   a gaze tracking device configured to monitor an ocular fixation of an observer; and   a controller configured to calculate pixel values for the plurality of sub-regions to determine a viewing angle corresponding to the ocular fixation of the observer, wherein the calculation of the pixel values is prioritized according to which of the plurality of sub-regions include pixels that are visible from within the viewing angle.    
     
     
       28. The system according to claim 27, wherein the calculation of the pixel values is further prioritized according to which of the plurality of sub-regions are located at an approximate center point of the ocular fixation.  
     
     
       29. The system according to claim 27, wherein the gaze tracking device is further configured to monitor a second ocular fixation of a second observer.  
     
     
       30. The system according to claim 29, wherein the viewing angle corresponds to both the first and second ocular fixations.  
     
     
       31. The system according to claim 27, wherein the pixels contribute to the generation of the three-dimensional image.  
     
     
       32. The system according to claim 27, wherein pixel values associated with pixels that are not visible from within the viewing angle are calculated after pixels values that are associated with pixels that are visible from within the viewing angle.  
     
     
       33. A method, comprising:
 monitoring an ocular point of fixation of an observer viewing a three-dimensional image;   determining a viewing angle corresponding to the ocular point of fixation;   identifying sub-regions of a display configured to produce the three-dimensional image in the viewing angle; and   calculating pixel values for the sub-regions, wherein the calculation of the pixel values is prioritized according to the identification of the sub-regions which produce the three-dimensional image.    
     
     
       34. The method according to claim 33, further comprising:
 monitoring a change in the ocular point of fixation of the observer to determine a new viewing angle; and   recalculating the pixel values to update the three-dimensional image in the new viewing angle.    
     
     
       35. The method according to claim 34, further comprising:
 identifying a plurality of sub-regions of the display configured to produce the updated three-dimensional image in the new viewing angle, wherein the plurality of sub-regions includes at least one sub-region that is different than the sub-regions of the display which are configured to produce the three-dimensional image.    
     
     
       36. The method according to claim 33, further comprising:
 identifying a change in the pixel values; and   recalculating the pixel values to update the three-dimensional image, wherein the pixel values that change receive a higher priority for calculation.    
     
     
       37. The method according to claim 33, further comprising:
 identifying an ocular point of fixation of a second observer viewing the three-dimensional image; and   determining a new viewing angle corresponding to the ocular points of fixation for both the observer and the second observer.    
     
     
       38. The method according to claim 37, wherein the new viewing angle is larger than the viewing angle.  
     
     
       39. The method according to claim 33, wherein the ocular point of fixation is monitored by detecting a position of a fovea of the observer.  
     
     
       40. The method according to claim 33, wherein the ocular point of fixation is positioned at an approximate ocular center point of the observer.  
     
     
       41. The method according to claim 33, wherein the calculation of the pixel values is prioritized according to which sub-regions include pixels that are visible from within the viewing angle.