Browse Prior Art Database

Efficient Algorithm for Perspective Transformation

IP.com Disclosure Number: IPCOM000108580D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 75K

Publishing Venue

IBM

Related People

Bird, CL: AUTHOR

Abstract

Described is a computationally efficient means of generating perspective image transformations by simple control of parameters derived from the required result.

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This is the abbreviated version, containing approximately 52% of the total text.

Efficient Algorithm for Perspective Transformation

       Described is a computationally efficient means of
generating perspective image transformations by simple control of
parameters derived from the required result.

      Perspective views are useful in certain applications, such as
in viewing layouts or maps.  This algorithm was motivated by the need
to efficiently compute projected images for the "chair" disclosed in
(1) which explicitly recognized that use of its projection option
would be a matter of choice owing to the computational expense
involved.  Image warping, using the Image Assistant/6000 function
"impwarp" in addition to performance considerations, also created an
undesirable curvature distortion in the result.  Another
transformation technique (2) is difficult to control and involves
considerable computation in performing the transformation.

      The method disclosed here involves the minimum of computation,
restricted to just what is necessary to achieve the result.  It
involves three parameters, which may be chosen (permuted) from the
four shown in Fig. 1, describing the perspective image.  The
orientation of the projection in Fig. 1 is chosen only as an example,
and the algorithm is not restricted to this orientation.  The method
has been fully implemented for the "chair", with h1, h2 and tan a as
the effective parameter set, as somewhat specific dimensional
conditions apply for the "chair", but the parameters affect only the
calculation of boundary conditions, not the method itself.  The
description...