Grade prediction of Pinus sylvestris logs with the aid of a radiograph image log

Today the internal structure of a log can be detected using X‐ray scanning technology. The objective of this study was to investigate the potential of grading a log by visual inspection of its longitudinal radiograph image (LRI). The grading accuracy of the LRI method was compared with the accuracy of a conventional manual log grading method. The grading accuracy was expressed as the ability to predict the grade of the centre planks of a log before the log was sawn. The grading results of the LRI method were determined by interviewing respondents connected with the wood and sawmill industry. The statistics of the conventional log grading method originate from the Swedish Stem Bank. The evaluation of the results was based on conventional statistical methods, unpaired significance tests and confidence intervals for means. This study shows that it is possible to grade logs by using LRIs. The grading accuracy is equal to, or better than, conventional log grading done by skilled graders from the Measurement So...