Stereoscopic imaging

Abstract

The invention represents a new form of stereoscopically-rendered three-dimensional model and various methods for constructing, manipulating, and displaying these models. The model consists of one or more stereograms applied to a substrate, where the shape of the substrate has been derived from the imagery or from the object itself, and the stereograms are applied to the substrate in a specific way that eliminates parallax for some points and reduces it in others. The methods offered can be (conservatively) 400 times more efficient at representing complex surfaces than conventional modelling techniques, and also provide for independent control of micro and macro parallaxes in a stereoscopically-viewed scene, whether presented in a VR environment or in stereo film or television.

1 . A method for forming a stereoscopic representation of a three-dimensional object, comprising the steps of:
 (a) providing a stereogram comprising first and second views of the object;   (b) selecting from the first and second views a plurality of pairs of corresponding image points relating to three-dimensional features which represent a basic shape of the object, and determining image coordinates for each selected point with reference to an image coordinate system of its respective view;   (c) determining a location of a natural convergence point or forced convergence point related thereto in three-dimensional space for each selected pair of corresponding image points;   (d) providing a substrate having a surface defined by a set of coordinates in three-dimensional space, the set of coordinates corresponding to locations of the natural convergence points or forced convergence points; and   (e) providing a data structure embodied on at least one of a record medium, a computer memory, a read-only memory, or an electrical carrier signal, containing a set of instructions for applying the first and second views to the substrate with each pair of corresponding image points applied to their respective coordinates on the surface of the substrate such that surface parallax is substantially eliminated for each selected pair of corresponding image points, and residual surface parallax occurs for at least some nonselected pairs of corresponding image points.   
     
     
         2 . A method according to  claim 1 , wherein the substrate is a three-dimensional representation of surface features of the basic shape of the object. 
     
     
         3 . A method according to  claim 1 , wherein the substrate comprises a plurality of discrete surface elements. 
     
     
         4 . A method according to  claim 3 , wherein the discrete surface elements are polygons. 
     
     
         5 . A method according to  claim 3 , wherein each selected pair of corresponding image points is applied to a corresponding vertex of a discrete surface element. 
     
     
         6 . A method according to  claim 2 , wherein the substrate is created using data derived from the stereogram. 
     
     
         7 . A method according to  claim 6 , wherein the substrate is created by:
 (f) determining a set of points in three-dimensional space at which pairs of mathematically projected rays passing respectively from each pair of corresponding image points, and through their respective perspective centers, intersect in three-dimensional space; and   (g) using the determined set of points in three-dimensional space to create the surface of the substrate, whereby the determined set of points on the surface correspond to the set of coordinates.   
     
     
         8 . A method according to  claim 2 , wherein the substrate is created using data derived directly from the object. 
     
     
         9 . A method according to  claim 8 , wherein the step of selecting a plurality of pairs of corresponding image points comprises:
 (f) determining the position and orientation of the substrate with respect to the perspective center of each of the first and second views; and   (g) selecting the plurality of pairs of corresponding image points by mathematically projecting rays from each of the coordinates defined by the surface of the substrate and through the respective perspective centers of the first and second views.   
     
     
         10 . A method according to  claim 1 , wherein the object is a virtual object (e.g. digital entity), and the stereogram is created by rendering of left and right views of the object. 
     
     
         11 . A method according to  claim 1 , wherein the substrate is a tangible entity existing in physical space. 
     
     
         12 . A method according to  claim 11 , wherein the substrate is configured of a material presenting a stereoscopic representation of the object to a user without using stereoscopic eyewear. 
     
     
         13 . A method according to  claim 12 , wherein the substrate comprises a lenticular screen. 
     
     
         14 . A method according to  claim 1 , wherein the substrate is a virtual substrate (e.g. digital entity). 
     
     
         15 . A method according to  claim 14 , further comprising the step of providing a set of user controls allowing a viewer to adjust the base separation between the rendered left and right views. 
     
     
         16 . A method according to  claim 1 , wherein the stereogram is one of a plurality of stereograms of a given view of the object, each stereogram of the plurality having a different base separation; and further providing a set of image coordinates for applying each stereogram of the plurality to the substrate. 
     
     
         17 . A method according to  claim 16 , further comprising the step of providing a set of user controls allowing a viewer to select which of the available stereograms should be applied to the substrate. 
     
     
         18 . A method according to  claim 1 , wherein the stereogram is provided with a first base separation which exceeds a range of parallax normally considered comfortable for human viewing; and further comprising the steps of:
 (f) digitally rendering the stereoscopic representation of the object using first and second virtual cameras having a second base separation which produces a range of parallax considered comfortable for human viewing; and   (g) recording and storing the digitally rendered stereoscopic representation of the object as a new stereogram.   
     
     
         19 . A method according to  claim 1 , further comprising displaying the stereoscopic representation using a system allowing selection of at least one additional pair of corresponding image points. 
     
     
         20 . A method according to  claim 19 , further comprising using the additionally selected pair of corresponding image points to create a new set of coordinates on the surface of the substrate to further define the surface of the substrate. 
     
     
         21 . A method according to  claim 19 , further comprising using at least one additionally selected pair of corresponding image points to derive measurements from points on the substrate corresponding to surface features of the object. 
     
     
         22 . A method according to  claim 1 , further comprising displaying the stereoscopic representation using a system allowing at least one of manipulation and annotation of the stereoscopic representation in three dimensions. 
     
     
         23 . A method according to  claim 1 , further comprising the steps of:
 (f) providing a first set of image coordinates for applying the first view of the stereogram onto the substrate; and   (g) providing a second set of image coordinates for applying the second view onto the substrate.   
     
     
         24 . A method according to  claim 23 , wherein the stereoscopic representation is rendered such that the first set of coordinates is used to apply the first view to the substrate when the first view is displayed, and the second set of coordinates is used to apply the second view to the substrate when the second view is displayed. 
     
     
         25 . A method according to  23 , wherein the substrate comprises first and second substrate components, each substrate component representing a basic shape of the object and having a surface defining a set of coordinates in three-dimensional space, and wherein the step of applying the first and second views of the stereogram to the substrate comprises using the first set of image coordinates to apply the first view to the first substrate component and using the second set of image coordinates to apply the second view to the second substrate component. 
     
     
         26 . A method according to  claim 1 , wherein:
 (f) the second view is warped such that each selected image point is made to coincide positionally with its corresponding image point in the first view;   (g) a set of image coordinates is provided for applying the first view of the stereogram onto the substrate; and   (h) the stereoscopic representation is rendered such that both the first view and the warped second view are applied to the substrate using the image coordinates of the first view.   
     
     
         27 . A method according to  claim 23 , further comprising repeating as necessary for real-time rendering using a simulation loop. 
     
     
         28 . A method according to  claim 1 , wherein the provided substrate is of an arbitrary shape. 
     
     
         29 . A method according to  claim 1 , where the substrate is subjected to a spatial transformation to provide a new shape. 
     
     
         30 . A method for forming a series of temporally sequenced stereoscopic representations of an object, comprising the steps of:
 (a) providing a plurality of stereoscopic representations each formed in accordance with the method of  claim 1 ; and   (b) arranging the plurality of stereoscopic representations in a sequence for viewing at a specified frame rate.   
     
     
         31 . A method according to  claim 30 , wherein a single substrate is used for forming a plurality of representations. 
     
     
         32 . A method according to  claim 11 , further comprising physically printing the stereogram onto the substrate. 
     
     
         33 . A computer-readable medium having stored thereon a data structure operable with a computer to allow the computer to form from data in the data structure stereoscopic representation of an object made in accordance with the method of  claim 1 . 
     
     
         34 . A computer-readable medium having stored thereon a computer program comprising program instructions for causing a computer to perform the process of  claim 1 . 
     
     
         35 . A computer-readable medium according to  claim 34 , wherein the computer-readable medium is a record medium. 
     
     
         36 . A computer-readable medium according to  claim 34 , wherein the computer-readable medium is a computer memory. 
     
     
         37 . A computer-readable medium according to  claim 34 , wherein the computer-readable medium is a read-only memory. 
     
     
         38 . Apparatus for forming a stereoscopic representation of an object, comprising a programmed computer with a program that when executed by the computer provides the following elements:
 (a) a stereogram generator for generating a stereogram comprising first and second views of the object;   (b) a selector module for selecting from the first and second views a plurality of pairs of corresponding image points relating to three-dimensional features which represent a basic shape of the object, and for determining image coordinates for each selected point with reference to an image coordinate system of its respective view;   (c) a locator module for determining a location of a natural convergence point or a forced convergence point related thereto in three-dimensional space for each selected pair of corresponding image points;   (d) a substrate generator for generating a substrate having a surface defined by a set of coordinates in three-dimensional space, the set of coordinates corresponding to locations of the natural convergence points or forced convergence points; and   (e) an applicator module for applying the first and second views to the generated substrate with each pair of corresponding image points applied to their respective coordinates on the surface of the substrate such that surface parallax is substantially eliminated for each selected pair of corresponding image points, and residual surface parallax occurs for at least some nonselected pairs of corresponding image points.   
     
     
         39 . An apparatus according to  claim 38 , wherein the substrate generator is configured to generate a substrate which is a three-dimensional representation of surface features of the basic shape of the object. 
     
     
         40 . An apparatus for forming a stereoscopic representation of an object, comprising an item comprising at least one of a record medium, a computer memory, a read-only memory, or an electrical carrier signal, the item having the following two elements stored therein:
 (a) a stereogram comprising first and second views of the object;   (b) a substrate having a surface defined by a set of coordinates in three-dimensional space, the set of coordinates corresponding to the location of at least one of natural convergence points and forced convergence points for each of a plurality of pre-selected pairs of corresponding image points relating to three-dimensional features which represent a basic shape of the object; and   (c) a computer programmed to provide an applicator device for applying the first and second views to the substrate with each pair of corresponding image points applied to their respective coordinates on the surface of the substrate such that surface parallax is substantially eliminated for the pre-selected pairs of corresponding image points and residual surface parallax occurs for at least some other pairs of corresponding image points.   
     
     
         41 . An apparatus according to  claim 40 , wherein the substrate is a three-dimensional representation of surface features of the basic shape of the object.