Department of Computing and Control Engineering, Faculty of Chemical Engineering, Institute of Chemical Technology, 166 28 Prague 6, Czech Republic.
Dentomaxillofac Radiol. 2013;42(7):20120391. doi: 10.1259/dmfr.20120391. Epub 2013 May 2.
The purpose of this study is (1) to introduce a new approach for edge detection in orthopantograms (OPGs) and an improved automatic parameter selector for common edge detectors, (2) to present a comparison between our novel approach with common edge detectors and (3) to provide faster outputs without compromising quality. A new approach for edge detection based on statistical measures was introduced: (1) a set of N edge detection results is calculated from a given input image and a selected type of edge detector, (2) N correspondence maps are constructed from N edge detection results, (3) probabilities and average probabilities are computed, (4) an overall correspondence is evaluated for each correspondence map and (5) the correspondence map providing the best overall correspondence is taken as the result of edge detection procedure. A comparison with common edge detectors (the Roberts, Prewitt, Sobel, Laplacian of the Gaussian and Canny methods) with various parameter settings (304 combinations for each test image) was carried out. The methods were assessed objectively [edge mismatch error (EME), modified Hausdorff distance (MHD) and principal component analysis] and subjectively by experts in dentistry and based on time demands. The suitability of the new approach for edge detection in OPGs was confirmed by experts. The current conventional methods in edge detection in OPGs are inadequate (none of the tested methods reach an EME value or MHD value below 0.1). Our proposed approach for edge detection shows promising potential for its implementation in clinical dentistry. It enhances the accuracy of OPG interpretation and advances diagnosis and treatment planning.
(1) 引入一种新的口内全景片（OPG）边缘检测方法和改进的通用边缘检测自动参数选择器；(2) 对比我们的新方法和通用边缘检测方法；(3) 提供更快的输出，而不影响质量。引入了一种基于统计测量的新边缘检测方法：(1) 从给定的输入图像和选定的边缘检测类型中计算一组 N 个边缘检测结果；(2) 从 N 个边缘检测结果构建 N 个对应图；(3) 计算概率和平均概率；(4) 为每个对应图评估整体对应关系；(5) 将提供最佳整体对应关系的对应图作为边缘检测过程的结果。对通用边缘检测方法（Roberts、Prewitt、Sobel、Gaussian 拉普拉斯和 Canny 方法）进行了比较，使用了各种参数设置（每个测试图像有 304 种组合）。方法通过客观评估（边缘不匹配误差 (EME)、改进的 Hausdorff 距离 (MHD) 和主成分分析）和牙医专家的主观评估进行评估，并基于时间需求进行评估。专家确认了新方法在 OPG 边缘检测中的适用性。目前 OPG 边缘检测中的常规方法不充分（测试的方法均未达到 EME 值或 MHD 值低于 0.1）。我们提出的边缘检测方法具有在临床牙科中应用的潜力。它提高了 OPG 解释的准确性，促进了诊断和治疗计划。
