Method of constructing three-dimensional image according to central projection method and apparatus for same

A method of constructing a three-dimensional image according to a central projection method, comprising the steps of:

• (a) determining first and second view points slightly shifted left and right and a first projection plane in an arithmetic unit so that a projection subject image read from a first memory is located between said first and second view points and said projection plane;
• (b) obtaining the first positional relation between a projection subject point on said projection subject image and a first projection point on said first projection plane;
• (c) obtaining the first distance between said first view point and said projection subject point;
• (d) determining the first pixel value of said first projection point on the basis of said first distance;
• (e) writing a value corresponding to said first pixel value into a second memory corresponding to said first projection plane;
• (f) obtaining the second positional relation between said projection subject point on said projection subject image and a second projection point on said first projection plane;
• (g) obtaining the second distance between said second view point and said projection subject point;
• (h) determining the second pixel value of said second projection point on the basis of said second distance;
• (i) writing a value corresponding to said second pixel value into a third memory corresponding to said first projection plane;
• (j) reading data from said second and third memories in accordance with a display area to construct two-in-a-set three-dimensional images which can be observed stereoscopically as a three-dimensional image;
• and
• (k) displaying said three-dimensional images.

An apparatus for constructing a three-dimensional image according to a central projection method, comprising:

• a storage means for storing a projection subject image;
• an arithmetic processing means including
• means for reading said projection subject image from said storage means and determining the position of a first view point and a first projection plane so that said projection subject image is located between the view point and the projection plane,
• means for obtaining the positional relation between a projection subject point on said projection subject image and a projection point on said first projection plane,
• means for obtaining the distance between said first view point and said projection subject point, and
• means for determining the pixel value of said projection point on the basis of said distance;
• a display memory means corresponding to said projection plane;
• means for writing a value corresponding to said pixel value into said display memory means;
• means for reading data from said display memory means in accordance with a display area to construct a three-dimensional image;
• and
• means for displaying said three-dimensional image.

A method of constructing a three-dimensional image according to a central projection method, comprising the steps of:

• (a) determining a position of a view point and a projection plane in an arithmetic unit so that an image to be projected read from a first memory is located between said view point and said projection plane;
• (b) assuming that an imaginary light source is located at said view point and projection lines are radially emitted from said view point and pass through said image to be projected, and determining a point to be projected on a projection line;
• (c) determining a quantity of light of said point to be projected on said projection plane;
• (d) determining a pixel value of a projected point projected on said projection plane on the basis of said quantity of light;
• (e) writing a value corresponding to said pixel value into a second memory corresponding to said projection plane;
• (f) performing said steps (b) through (e) for each point to be projected of said image to be projected;
• (g) reading data from said second memory in accordance with a display area to construct a three-dimensional image;
• and
• (h) displaying said three-dimensional image.

A central projection method comprising the steps of:

• (a) determining a position of a view point and a projection plane in an arithmetic unit so that an image to be projected read from a first memory is located between said view point and said projection plane;
• (b) setting a curved surface touching said projection plane at an origin of a rectangular three-dimensional coordinate system containing said projection plane as an X-Y plane so that said view point is located on a line connecting a center of said curved surface and said origin, and said image to be projected is located between said view point and said curved surface;
• (c) projecting a point to be projected onto said curved surface to obtain a first projected point Q on said curved surface;
• (d) obtaining a length L along said curved surface between said first projected point Q and said origin;
• and
• (e) projecting said projected point Q onto said projection plane with said length L to obtain a second projected point on said projection plane.

A method of constructing a three-dimensional image according to a central projection method, comprising the steps of:

• setting a view point, one or more images to be projected, and a projection plane in a memory space so that the one or more images to be projected are located between the view point and the projection plane;
• obtaining an enlarged projected image on the projection plane viewed from the view point by a central projection method and determining pixel values of the projection plane;
• and
• constructing a three-dimensional image on the basis of the pixel values and displaying the three-dimensional image.

A method of constructing a three-dimensional image according to a central projection method, comprising the steps of:

• setting a view point, one or more images to be projected, and a projection plane in a memory space so that a perpendicular from the view point to the projection plane is longer than a distance between the view point and a pixel point of the one or more images to be projected;
• setting a curved surface having a center on a straight line defining a view line extending from the view point to the one or more images to be projected, the curved surface passing through the view point;
• projecting the pixel point of the one or more images to be projected onto the curved surface and the projection plane, and obtaining a projected point Q on the curved surface and a projected point P on the projection plane;
• measuring a distance L along the curved surface between the projected point Q and a point, other than the view point, at which the view line intersects the curved surface;
• and
• obtaining a projected point G on the projection plane, the projected point G corresponding to the projected point Q and being located on a line extending from a point at which the view line intersects the projection plane to the projected point P at a distance equal to L from the point at which the view line intersects the projection plane.

A method of constructing a three-dimensional image according to a central projection method, comprising the steps of:

• setting a view point, one or more images to be projected, and a projection plane in a memory space so that the one or more images to be projected are located between the view point and the projection plane;
• setting a curved surface having a center on a straight line defining a view line extending from the view point to the one or more images to be projected, the curved surface passing through the view point;
• projecting a pixel point of the one or more images to be projected onto the curved surface and the projection plane, and obtaining a projected point Q on the curved surface and a projected point P on the projection plane;
• measuring a distance L along the curved surface between the projected point Q and a point, other than the view point, at which the view line intersects the curved surface;
• and
• obtaining a projected point G on the projection plane, the projected point G corresponding to the projected point Q and being located on a line extending from a point at which the view line intersects the projection plane to the projected point P at a distance equal to L from the point at which the view line intersects the projection plane.