Distance Transform



A distance transform, also known as distance map or distance field, is a representation of a distance function to an object, as an image. Such maps are used in several applications, especially in document image analysis. Some optimizations can be obtained by less generic methods: for example, maps calculated by front propagation can determine shorter paths, assuming that the image is non-convex. This presentation discusses different distance transform algorithms and underlines their advantages and weaknesses. Finally we will explain our choices.