Classification of voting patterns to improve the generalized Hough transform for epiphyses localization
Ferdinand Hahmann, Gordon Böer, Eric Gabriel, Thomas Martin Deserno, Carsten Meyer, Hauke Schramm · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2016
This paper presents a general framework for object localization in medical (and non-medical) images. In particular, we focus on objects of well-defined shape, like epiphyseal regions in hand-radiographs, which are localized based on a voting framework using the Generalized Hough Transform (GHT). We suggest to combine the GHT voting with a classifier which rates the voting characteristics of the GHT model at individual Hough cells. Specifically, a Random Forest Classifier rates whether the model points, voting for an object position, constitute a regular shape or not, and this measure is combined with the GHT votes. With this technique, we achieve a success rate of 99.4% for localizing 12 epiphyseal regions of interest in 412 hand- radiographs. The mean error is 6.6 pixels on images with a mean resolution of 1185×2006 pixels. Furthermore, we analyze the influence of the radius of the local neighborhood which is considered in analyzing the voting characteristics of a Hough cell.