TY  - JOUR
AU  - Schuchert, T.
AU  - Aach, T.
AU  - Scharr, H.
TI  - Range Flow in Varying Illumination: Algorithms and Comparisons
JO  - IEEE transactions on pattern analysis and machine intelligence
VL  - 32
SN  - 0162-8828
CY  - New York, NY
PB  - IEEE
M1  - PreJuSER-1797
SP  - 1646 - 1658
PY  - 2010
N1  - Record converted from VDB: 12.11.2012
AB  - We extend estimation of range flow to handle brightness changes in image data caused by inhomogeneous illumination. Standard range flow computes 3D velocity fields using both range and intensity image sequences. Toward this end, range flow estimation combines a depth change model with a brightness constancy model. However, local brightness is generally not preserved when object surfaces rotate relative to the camera or the light sources, or when surfaces move in inhomogeneous illumination. We describe and investigate different approaches to handle such brightness changes. A straightforward approach is to prefilter the intensity data such that brightness changes are suppressed, for instance, by a highpass or a homomorphic filter. Such prefiltering may, though, reduce the signal-to-noise ratio. An alternative novel approach is to replace the brightness constancy model by 1) a gradient constancy model, or 2) by a combination of gradient and brightness constancy constraints used earlier successfully for optical flow, or 3) by a physics-based brightness change model. In performance tests, the standard version and the novel versions of range flow estimation are investigated using prefiltered or nonprefiltered synthetic data with available ground truth. Furthermore, the influences of additive Gaussian noise and simulated shot noise are investigated. Finally, we compare all range flow estimators on real data.
KW  - Algorithms
KW  - Artifacts
KW  - Artificial Intelligence
KW  - Image Enhancement: methods
KW  - Image Interpretation, Computer-Assisted: methods
KW  - Imaging, Three-Dimensional: methods
KW  - Lighting: methods
KW  - Pattern Recognition, Automated: methods
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:20634558
UR  - <Go to ISI:>//WOS:000279969000008
DO  - DOI:10.1109/TPAMI.2009.162
UR  - https://juser.fz-juelich.de/record/1797
ER  -