Estimation of Feret's diameter from pixel coverage representation of a shape

Feret's diameter of a shape is a commonly used measure in shape analysis. Traditional methods for estimation of Feret's diameter are performed on binary images and are of poor precision and accuracy. We analyze and further develop a method for estimation of Feret's diameter that utilizes pixel coverage. We improve the accuracy of the method by proposing a correction term. We provide an expression for the upper bound of the absolute error of the estimation. We evaluate the improved method and compare with existing methods for Feret's diameter estimation, based on both binary and coverage representations of image objects. Tests confirm increased precision and accuracy of the new method, on synthetic as well as on real images. (C) 2016 Elsevier B.V. All rights reserved.