Browse Prior Art Database

Rendering of 3D Image Via Interpolated Z-Buffer Gradient

IP.com Disclosure Number: IPCOM000105702D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 4 page(s) / 62K

Publishing Venue

IBM

Related People

Hanson, WA: AUTHOR

Abstract

An algorithm is disclosed for high quality rendering of 3D images such as those found in medical imaging and industrial imaging applications.

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This is the abbreviated version, containing approximately 56% of the total text.

Rendering of 3D Image Via Interpolated Z-Buffer Gradient

      An algorithm is disclosed for high quality rendering of 3D
images such as those found in medical imaging and industrial imaging
applications.

      A variety of methods currently exist for the rendering of 3D
images into 2D pictures suitable for display on conventional computer
terminals [*].  A major category of these are the surface rendering
methods which visualize an isosurface within the image.  The
isosurface is characterized by some threshold constant c.  These
methods all involve the evaluation of a surface normal that is then
used to compute a visualization parameter.  The visualization
parameter is typically a mixture of the Phong value and the surface
specularity:

     &Phi = N : L = Phong reflection

     &Psi = N : E = specularity
           N = surface normal
           L = light source
           E = eye or viewing direction

      Although a method does currently exist that uses the depth
estimate for the evaluating the normal, the most popular method of
estimating the normal is to use the so-called grey-level gradient.
This method computes the rate of change of the original intensity
space.

      The proposed algorithm computes the normal using a high
resolution Z-buffer and estimates the normal directly from the
manifold described by the Z-buffer.  First, the Z-buffer is evaluated
by interpolating the known raster intensities to extrac...