Evaluation of steerable filter for detection of fibres in flowing suspensions
2011 (English)In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 51, no 4, 987-996 p.Article in journal (Refereed) Published
Steerable filters are concluded to be useful in order to determine the orientation of fibers captured in digital images. The fiber orientation is a key variable in the study of flowing fiber suspensions. Here, digital image analysis based on a filter within the class of steerable filters is evaluated for suitability of finding the position and orientation of fibers suspended in flowing suspensions. In sharp images with small noise levels, the steerable filter succeeds in determining the orientation of artificially generated fibers with well-defined angles. The influence of reduced image quality on the orientation has been quantified. The effect of unsharpness and noise is studied and the results show that the error in orientation is less than 1° for moderate levels. Images from two flow cases, one laminar shear flow and one turbulent, are also analyzed. The fiber orientation distribution is determined in the flow-vorticity plane. For the laminar case a comparison is made to a robust, but computationally more expensive, method involving convolutions with an oriented elliptic filter. A good agreement is found when comparing the resulting fiber orientation distributions obtained with the two methods. For the turbulent case, it is demonstrated that correct results are obtained and that the method can handle overlapping fibers.
Place, publisher, year, edition, pages
2011. Vol. 51, no 4, 987-996 p.
Digital image, Digital image analysis, Elliptic filters, Fiber orientation distribution, Fiber suspensions, Flow-vorticity plane, Key variables, Laminar shear flow, Noise levels, Overlapping fibers, Steerable filters
Engineering and Technology Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-89280DOI: 10.1007/s00348-011-1115-1ISI: 000295174800009ScopusID: 2-s2.0-80053561537OAI: oai:DiVA.org:kth-89280DiVA: diva2:502908
QC 201202152012-02-142012-02-142012-02-15Bibliographically approved