Micro CT scanner rendering images. Images of the top of the sample.
Laboratory measurements to determine the grain size
distribution of the bed surface and substrate
Clara Orru , Astrid Blom , Wim Uijttewaal
1Method 1: Image analysis combined with particle coloring
Objective
Image processing procedure based on color segmentation.
1: Delft University of Technology, Faculty of Civil Engineering, Environmental Fluid Mechanics Section. P.O. Box 5048, 2600 GA Delft, The Netherlands. E-mail: C.Orru@tudelft.nl. Coarse Medium Fine F:M:C 17%:33%:50% F:M:C 17%:33%:50% F:M:C 50%:33%:17% F:M:C 33%:33%:33% F:M:C 33%:33%:33% Fine Medium Medium:Coarse Medium Fine Medium:Coarse Fine Medium Coarse 49cm 34.5cm 33cm 32cm 6cm
To measure the grain size distribution of the bed surface and substrate in flume experiments to
provide new insights in grain size-selective pro-cesses.
Experiment to assess two image analysis techniques
Pictures of submerged bed show better color segmentation.
Coloring of all grain size fractions provides better color segmentation.
Environmental Fluid
Mechanics Section
Bed sampling technique.
Method 2: Three-dimensional imaging combined with core sampling
F3 F1
Segmented pictures (blue)
Pictures without water Original pictures Pictures with water
Segmented pictures (blue)
Pictures without water Original pictures Pictures with water Pictures without water Original pictures Pictures with water 1 1
Color segmentation result
CT scanner result
3D reconstruction Grain segmentation
Original image Image after color saturation Image after color segmentation with labeled pixels
Segmented images for the 3 colors
F2
Installed sediment layers in side view of CT scan