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Minimising algorithm‐induced artefacts in true ortho‐image generation: a direct method implemented in the vector domain
Author(s) -
Sheng Yongwei
Publication year - 2007
Publication title -
the photogrammetric record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 51
eISSN - 1477-9730
pISSN - 0031-868X
DOI - 10.1111/j.1477-9730.2007.00425.x
Subject(s) - artificial intelligence , computer vision , perspective (graphical) , image (mathematics) , computer science , pixel , algorithm , point (geometry) , displacement (psychology) , distortion (music) , domain (mathematical analysis) , process (computing) , resampling , mathematics , psychology , amplifier , computer network , mathematical analysis , geometry , bandwidth (computing) , psychotherapist , operating system
True ortho‐images are generated from perspective images with both object and terrain displacement distortion corrected and with occlusions removed. However, widely used algorithms based on a Z‐buffer have drawbacks and may result in artefacts in the generated ortho‐images. This paper analyses the artefacts induced by Z‐buffer algorithms in true ortho‐image generation, and proposes a vector‐based method to avoid algorithm‐induced artefacts. The proposed method treats a perspective image pixel as a square patch instead of an image pixel point, and generates ortho‐images in the vector domain. Under the vector implementation, occlusion detection is a simple process, and image resampling becomes a straightforward procedure. Most importantly, this method can minimise artefacts in the ortho‐images so generated.