The spacing transform: Application and validation

Abstract The measurement of spacing via the linear intercept method is a stereology technique for quantifying microstructures. Spacing measurements have traditionally been acquired using manual or semi-automatic methods. However, in recent work, the stereology idea of spacing was shown to be closely related to the computer vision idea of distance. If the distance transform can be defined as providing the minimum distance required at a given location to reach the nearest edge, a spacing transform would be defined as providing the distance required at a given location to reach the desired number of nearest consecutive edges along a linear path. The resultant transformed image provides local spacing data which should be the same as those measured by an expert stereologist. This spacing transform addresses the problem of measuring spacing in an interpretable and easily validated fashion. In this paper, spacing transform is defined, applied to real world images, and validated against traditional stereology methods.