Depth map generating method and apparatus

Claim 1

A depth map generating apparatus comprising: a depth map memory for storing a depth map; three-dimensional (3D) region setting means for setting in 3D coordinates a 3D region of a given shape enclosing an object in 3D image data; first processing means for acquiring through a coordination computation a first distance measured in a desired view direction from a projection plane, a position of said projection plane being set in accordance with said desired view direction, said first direction measured to a surface of said 3D region, and said first processing means acquiring said first distance for each corresponding pixel on said projection plane; second processing means for acquiring through ray tracing a second distance measured in said desired view direction from said surface of said 3D region to a surface of said object, the second processing means acquiring a second distance for each corresponding pixel on said projection plane; and third processing means for adding said first and second distances for each corresponding pixel on said projection plane and writing resultant data in said depth map memory.

Claim 9

An apparatus for displaying a three-dimensional image, comprising: image data memory means for storing voxel data representing a three-dimensional object; processing means for obtaining total distances between points on a surface of said three-dimensional object and a projection plane orthogonal to a desired view direction, said processing means including: three-dimensional region determining means for determining a three-dimensional region enclosing said threedimensional object, whereby each of said total distances is divided into a first distance measured between said projection plane and the surface of said three-dimensional region and a second distance measured between the surface of said three-dimensional region and the surface of said threedimensional object, coordinate computation means for determining lengths of the first distances, with respect to each pixel on said projection plane, by coordinate computation, ray tracing means for determining lengths of the second distance with respect to each pixel on said projection plane by ray tracing, and adding means for adding the lengths of the first and second distances together to obtain each of said total distances, and displaying means for displaying an image on a twodimensional screen in a gradation corresponding to said total distances obtained by said adding means.

Claim 10

An apparatus for displaying a three-dimensional image, comprising: image data memory means for storing voxel data representing a three-dimensional object; processing means for obtaining total distances between points on a surface of said three-dimensional object and a projection plane orthogonal to a desired view direction, said processing means including: three-dimensional region determining means for determining a three-dimensional region enclosing said threedimensional object, whereby each of said total distances is divided into a first distance measured between said projection plane and the surface of said three-dimensional region and a second distance measured between the surface of said three-dimensional region and the surface of said threedimensional object, coordinate computation means for determining lengths of the first distances, with respect to each pixel on said projection plane, by coordinate computation, ray tracing means for determining lengths of the second distance with respect to each pixel on said projection plane by ray tracing, and adding means for adding the lengths of the first and second distances together to obtain each of said total distances, and displaying means for displaying an image on a twodimensional screen in a gradation corresponding to said total distances obtained by said adding means.