Minimising algorithm‐induced artefacts in true ortho‐image generation: a direct method implemented in the vector domain
Yongwei Sheng · The Photogrammetric Record · 2007
Abstract 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.