Plant and Soil

, Volume 158, Issue 1, pp 145–149

Automated measurement of root length with a three-dimensional high-resolution scanner and image analysis


  • A. L. Smit
    • Centre for Agrobiological Research (CABO-DLO)
  • J. F. C. M. Sprangers
    • Department of Vegetation Science, Plant Ecology and Weed ScienceAgricultural University Wageningen
  • P. W. Sablik
    • Technical and Physical Engineering Research Service (TFDL-DLO)
  • J. Groenwold
    • Centre for Agrobiological Research (CABO-DLO)
Short Communication

DOI: 10.1007/BF00007928

Cite this article as:
Smit, A.L., Sprangers, J.F.C.M., Sablik, P.W. et al. Plant Soil (1994) 158: 145. doi:10.1007/BF00007928


For measuring the length of root samples, the use of a three-dimensional (3D) scanner is proposed to address the problem of a too low resolution. The scanner's high resolution (up to 354 pixels per cm) enables in the resulting grey-value image very thin roots (diameter 100 μm) to be segmented from the background by a simple thresholding operation. After skeletonizing, total length of the roots is calculated by multiplying the number of skeleton pixels by a correction factor. A comparison with the modified Newman Line-Intersect Method showed a correlation of r=0.98. Besides its superior resolution, an advantage of this type of scanner is its focusing depth, which allows root samples to be recorded on the scanbed similarly to a camera-oriented system.

Key words

image analysisLine-Intersect Methodroot lengththree-dimensional scanner

Copyright information

© Kluwer Academic Publishers 1994