Evaluating Fibrous Architecture of Nonwovens with Computer-Assisted Microscopy 1

Abstract

A new computerized imaging, circular polarized light microscopy technique is de veloped to measure the orientation of fibers in images of nonwovens. The system consists of a modified Olympus BX50 polarized microscope, a Sony AVC-D7 video camera, and a Silicon Graphics Indy computer. There are two methods of image seg mentation : Gaussian distribution' based minimum error thresholding and Poisson dis tribution based minimum error thresholding. Segments of fiber midlines are traced with vertical and horizontal scanlines or, alternatively, whole midlines are identified recur sively with the Hilditch technique. The fiber midlines produced with this technique are traversed by a midline traversal algorithm, and the orientation distribution is obtained by least squares line fitting. The accuracy of the technique is evaluated against synthetic images composed of straight lines and sinuous curves. Kupier's statistic is used to evaluate the consistency of the fiber orientation calculations. A statistical analysis of the results shows that the proposed Hilditch connectivity, which preserves skeletoni zation, produces the most accurate results.

Distance transform algorithm for measuring nanofiber diameter

“…In the last few years, image analysis methods have been developed in order to identify fibers and measure nonwoven characteristics such as fiber orientation [9][10][11][12][13][14][15][16], fiber diameter [17,18], pore size [19], [20], uniformity [21] and other structural features [15,22]. However, since these are new techniques and their accuracy and limitations have not been verified, samples with known characteristics are required to evaluate the accuracy of the methods which can be produced by simulation schemes [9,23].…”

Analysis of Orientations of Collagen Fibers by Novel Fiber-Tracking Software

“…Currently available image-processing methods for exploring orientation of individual fibers require either skel-etonization~Pourdeyhimi et al, 1996a, 1996b, 1997a, 1997b! or Hilditch thinning~Krucinska et al, 1997Krucinska, 1999aKrucinska, , 1999b!. These approaches have several drawbacks.…”

Automated quantification and reconstruction of collagen matrix from 3D confocal datasets

“…The Hough transform, which is generally used for line detection, is unreliable for irregular curves such as collagen fibres (Hough, 1962; Davidson & Clarke, 1999). Skeletonizing (thinning) with a direct tracking method can identify individual fibres, but is time‐consuming and produces many artefacts owing to variations on the boundaries (Krucinska, 1999; Pourdeyhimi et al ., 1996). Measurement of the elliptical parameters of a fibre's image could determine its 3D orientation, but this approach always has 180° angle ambiguity and depends on many additional assumptions (Yurgartis, 1987; Hine et al ., 1993, 1995).…”