A lung x-ray, thresholded using a correlation between Euler number and pixel importance in diagnosis

The Euler Number of a Binary Image

Let’s start with the basics: what is an Euler number? You may have seen this formula before, perhaps in a discrete mathematics class:

Euler’s formula. You know it’s important with a name like that.

V stands for the number of vertexes, E the number of edges, and F the number of faces. In graph…