An Automated Optical Liquid Film Thickness Measurement Method
APPLICATION OF AN AUTOMATED MICROTOMY METHOD IN …
Transcript of APPLICATION OF AN AUTOMATED MICROTOMY METHOD IN …
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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APPLICATION OF AN AUTOMATED
MICROTOMY METHOD IN THE TRACKING
OF FIBERS IN 3D PAPER STRUCTURES
M. Wiltsche1, W. Bauer1 and M. Donoser2
1 Institute for Paper, Pulp and Fiber Technology2 Institute for Computer Graphics and Vision
Graz University of Technology, Austria
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Outline
• Introduction
• Automated Microtomy Concept– Digitization of paper samples
– Image analysis for detection of individual fibers
• Initial Results
• Conclusion and Outlook
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Why 3D Paper Structure Analysis?
• Paper is a heterogeneous material– Fibers and fiber fragments
– Fillers and pigments
– One or more coating layers
• Numerous functional paper properties are influenced
by the spatial arrangementE.g. strength properties, dimensional stability, printability ...
→ 3D analysis of paper structure can provide valuable information
• Capability of accessing individual fibers or pores is
crucial
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Requirements in Digitizing 3D Paper Structure
• True three dimensional representation of structure
• High spatial resolution � > 1 µm
• Sufficient sample size � > some mm²
• Applicability in „day-to-day“ research on commercial
paper samples– Time in the order of hours
– Moderate investment and operating costs
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Currently Applied Digitization Methods
• Non-destructive Methods– Confocal Laser Scanning Microscopy (CLSM)
– X-ray microtomography
• Micro-focus X-ray tube microtomography (low resolution: ≈ 5-10 µm)
• Synchrotron radiation microtomography (high resolution: ≈ 1- 2 µm)
– Optical coherence tomography (OCT)
– Nuclear magnetic resonance (NMR) imaging
– Ultrasonic microscopy
• Destructive Methods– Sheet splitting
– Serial sectioning
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
In-situ analysis of
individual elements in paper structures
• Yang et al. [1]
– Operator identified points along the perimeter of each fiber by hand
– State of bonding and fiber properties were evaluated
• Hasuike et al. [2]
– Contour of fiber cross sections was identified manually
– Bonding state and 3D fiber orientation distribution were determined
• Aronsson [3]
– Automated detection and tracking of individual fibers
– Three different approaches, some user-interaction needed
• Sintorn et al. [4]
– Automated segmentation of individual pores
[1] C.-F. Yang, A.R.K. Eusufzai, R. Sankar, R.E. Mark, and R.W. Perkins Jr. Measurements of geometrical parameters of fiber networks. Part 1.
Svensk Papperstidning, 81(13):426–433, 1978.
[2] M. Hasuike, T. Kawasaki, and K. Murakami. Evaluation method of 3-D geometric structure of paper sheet. Journal of Pulp and Paper Science,
18(3):J114–J120, 1992.
[3] M. Aronsson. On 3D Fibre Measurements of Digitized Paper. PhD thesis, Swedish University of Agricultural Sciences, Uppsala (Sweden), 2002.
[4] I.-M. Sintorn, S. Svensson, M. Axelsson, and G. Borgefors. Segmentation of individual pores in 3D paper images. Nordic Pulp and Paper Research
Journal, 20(3):316–319, 2005.
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Outline
• Introduction
• Automated Microtomy Concept– Digitization of paper samples
– Image analysis for detection of individual fibers
• Initial Results
• Conclusion and Outlook
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Automated Microtome
Rotary microtomeMoveable stage
Cut block (embedded sample)Optical microscope
CMOS camera
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Automated Microtome
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Operating Sequence
• Preparation of the microtome
• Setting required parameters for digitization– Region-of-interest (ROI)
– Number of cuts
– Camera and light settings
– Miscellaneous parameters (sample ID, cut thickness, …)
• Start of the automated digitization loop– Software activates the first microtome cut
– Specimen head of microtome stops in upper limit automatically
– Scanning of the block surface
– Microtome cuts next section
→ Result: Set of images comprising 3D paper structure.
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Digital 3D Representation of
Digitized Paper Structure
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Specification Parameters Automated Microtome
• Minimum pixel size 0.16 µm
• Maximum resolution 0.61 µm
• Practical cut thickness 1 µm – 8 µm
• Time duration for one cut 20 s – 80 s
• Example for a large data set– Sample area 1.6 × 2.65 mm²
– Voxel size 0.16 × 5 × 0.16 µm³ (CD × MD × ZD)
– Number of cuts 530
– Images per cut 11
→ Total amount of image data 21.3 GB
→ Time need for digitization 8.9 h
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Base sheet topography under coating
Local coating thickness
Commercial, calendered WFC sample.
Application in 3D Analysis
of Coating Layer Formation
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Outline
• Introduction
• Automated Microtomy Concept– Digitization of paper samples
– Image analysis for detection of individual fibers
• Initial Results
• Conclusion and Outlook
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Concept to Build a
3D Representation of Individual Fibers
• Concept is based on MSER-Tracking [5]
• Two main steps:– Segmentation of individual fibers in a slice image
Maximally Stable Extremal Regions (MSER) are identified automatically
as bright areas with dark boundaries
– Tracking of these detected fiber regions through image sequence
Correspondences between regions in subsequent slice images are built
• Result: Sequence of label images, wherein each
detected fiber is assigned a unique ID
[5] M. Donoser and H. Bischof. Efficient maximally stable extremal region (MSER) tracking. In Proceedings of the IEEE Computer Society
Conference on Computer Vision and Pattern Recognition (CVPR), vol. 1, pp. 553–560, New York (USA), June 2006.
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Working Principle of MSER-Tracking
Typical input image.
Resulting label image.
Input image including
boundaries of tracked fibers.
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Outline
• Introduction
• Automated Microtomy Concept– Digitization of paper samples
– Image analysis for detection of individual fibers
• Initial Results
• Conclusion and Outlook
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Further Analysis of Label Images
Cross section area, fiber centroid,
morphological data ….
Follow cross section
area through image
stack
Follow fiber centroid through
image stack
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Remarks to Analyzed Sample
• Commercial kraft paper sample– Made on a fourdrinier-machine
• Voxel size: 0.16 × 5 × 0.16 µm³ (CD × MD × ZD)
• Small image stack comprising 20 frames was analyzed
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Trend of Fiber Centroid Coordinates
• Fibers are moving intensively in CD
• Rather stable in ZD
→ Indication for a predominately layered fiber network.
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Video Sequence
of these Results
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Surface Renderings of Tracked Fibers
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Fibre Morphological Data from Label Images
Visible lumen,
uncollapsed fibers
Group A
Lumen not visible,
fully collapsed fibers
Group B.1
Lumen partially visible,
partially collapsed fibers
Group B.2
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Determination of Local Fiber Wall Thickness
→
→Fibers with
visible lumen
Fully collapsed
fibers
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Determination of Degree of Collapse
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Outline
• Introduction
• Automated Microtomy Concept– Digitization of paper samples
– Image analysis for detection of individual fibers
• Initial Results
• Conclusion and Outlook
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Conclusions & Outlook
• The presented prototype is capable of digitizing
micro-structure of paper– at high resolution,
– with sufficient sample size and
– at moderate costs.
• Obtained 3D image data enables detailed fiber
network analysis
• Future challenge: increase the percentage of
detected fibers– Enhancement of image quality
– Further development of the tracking algorithm
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Acknowledgements
The authors gratefully acknowledge financial support of:– Austrian Research Promotion Agency Ltd. (FFG)
– Mondi Business Paper Austria
– Mondi Packaging Frantschach
– M-Real Hallein
– Norske Skog Bruck
– Sappi Gratkorn
– SCA Graphic Laakirchen
– UPM Steyrermühl
– Voith Paper
Institute for Paper, Pulp and Fiber Technology
Professor Horst Cerjak, 19.12.2005
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Tracking of Fibers in 3D Paper Structures COST E54 Opening Seminar, Riga, April 2007
Thank you
for your attention.
3D STRUCTURE