Application and Accuracy of the Free Image Analysis Software for Tree-ring Measurement Compared with the Standard Tree-ring Measuring System -
Patsi Prasomsin1, Khwanchai Duangsathaporn1, A. Yenemurwon Omule1, Pichit Lumyai1, Supasit Sriarkarin, Thanyaporn Bungbai, La-ongdao Thaopimai, and Kritsadapan Palakit
Accurate ring width data is an important precursor for tree-ring analysis. This study aimed to apply image analysis software, namely ImageJ, to measure the annual ring widths of Pinus kesiya, as a case study, and compare its accuracy with the standard measurement derived from the Velmex measuring system. The accuracy of measurement was compared by using the Verify for Windows software and the paired sample t-test. It was found that ring width data from these measuring techniques were significantly correlated (r = 0.99; p = 0.000) and the measurements in each increment core were not significantly different. The application of climate-growth responses has shown the similarity of the relationship between ring width data derived from the two techniques and climatic data. Therefore, to increase the capacity and opportunity in tree-ring study, the image analysis using ImageJ software can be applied and its accuracy is not significantly different from that of a standard instrument under the conditions of proper sample preparation for image scanning and the correct cross-dating.