Determination of vessel elements and computation of hydraulic conductance of hardwood species images using digital image processing technique

This paper presents an approach to segment the light microscopic images of hardwood species and then extract only the vessel elements out of the images. In this work, an effort was made to propose a platform-independent tool based on simple digital image processing technique to quantify wood conduits (especially vessel elements at present). A prototype model was developed and tested on several microscopic images prepared at the xylarium (DDw) of the Wood Anatomy Discipline of the Forest Research Institute, Dehradun, India. The investigation of the experimental work suggests that for most of the images, with the help of appropriate parameter selection, the vessel elements were extracted. In one case, the identified vessel element area was in fact the area of vessel element plus the surrounding parenchyma elements area. Close observation of the aforementioned object in original color (RGB) image suggests that the parenchyma elements surrounding the vessel elements have higher intensity level, in contrast to other parenchyma elements. This happened because an intensity-based thresholding approach was used for converting an RGB image to a binary image. Further, along with the extraction of vessel elements, the proposed model is capable of computing the hydraulic conductivity and lumen resistivity of the vessel elements.