Centre for Integrative Medicine, University of Witten/Herdecke, Witten, Germany.
PLoS One. 2013;8(4):e60522. doi: 10.1371/journal.pone.0060522. Epub 2013 Apr 2.
Photographs of mistletoe (Viscum album L.) berries taken by a permanently fixed camera during their development in autumn were subjected to an outline shape analysis by fitting path curves using a mathematical algorithm from projective geometry. During growth and maturation processes the shape of mistletoe berries can be described by a set of such path curves, making it possible to extract changes of shape using one parameter called Lambda. Lambda describes the outline shape of a path curve. Here we present methods and software to capture and measure these changes of form over time. The present paper describes the software used to automatize a number of tasks including contour recognition, optimization of fitting the contour via hill-climbing, derivation of the path curves, computation of Lambda and blinding the pictures for the operator. The validity of the program is demonstrated by results from three independent measurements showing circadian rhythm in mistletoe berries. The program is available as open source and will be applied in a project to analyze the chronobiology of shape in mistletoe berries and the buds of their host trees.
使用从投影几何中得出的数学算法拟合路径曲线，对固定相机在秋季拍摄的槲寄生浆果的照片进行轮廓形状分析。在生长和成熟过程中，槲寄生浆果的形状可以由一组这样的路径曲线来描述，从而可以使用一个称为“Lambda”的参数提取形状的变化。“Lambda”描述了路径曲线的轮廓形状。在这里，我们介绍了捕获和测量这些随时间变化的形状的方法和软件。本文介绍了用于自动化多项任务的软件，包括轮廓识别、通过爬山法优化拟合轮廓、导出路径曲线、计算“Lambda”以及对操作人员进行图片屏蔽。通过三个独立测量结果证明了该程序的有效性，这些结果显示了槲寄生浆果中的昼夜节律。该程序是开源的，将应用于分析槲寄生浆果及其宿主树芽的形状的生物钟项目。
