This paper is devoted to the development of the software for online log deck volume measurement via photometry. Log volume measurement is based on the analysis of its cut which specific feature is rounded shape. Thus the development of the rounded object automatic detection method has to be the main part of the R&D. It was decided to use the fast radial symmetry algorithm as a basis of the detection method. Then its modification according to the specific of the application scope was implemented. The obtained method was introduced into the developed software. Analysis of its testing on 700 images gives the average probability of target object detection at 95,7% with lower range at 86%.