In this chapter some details about the available segmentation (/detection) methods are explained. This chapter is complementary to the user inter face help on Particle and Pore Analysis and in the Best Practice Guide which should also be read.
For the purpose of explaining the two detection methods it is useful to regard an image as a topographic landscape. Both detection methods can then be described by considering the behavior of water in this landscape. To get a clear idea of the term topographic landscapes see the example below. At the left is an image in normal 2D view. At the right you see a projection of the topographic representation.
This metaphor applies whether the image is a true topographic image, for example an SPM image, actually measuring physical heights on a surface, or the image is a conventional optical image or any other type of image.
For the Threshold Segmentation method we define Particles and Pores based on a threshold level:
Using the analogy of water flooding a landscape, Particles are the islands left when the landscape is flooded to the threshold level; Pores is all below the water surface.
Consider the 1-Dimensional signal represented by the upper curve in the figure. When a threshold is chosen indicated by the red horizontal stippled line, a binary condition is imposed. Only the part of the signal above the threshold is considered Particles. Correspondingly in the lower curve, the parts below the Pore Threshold Level indicated by the blue stippled line are considered Pores.
