Wiesner Group - Pattern Analysis

Voronoi and Nearest Neighbor Pattern Analysis Algorithms

The program can then perform Delaunay triangulation which analyzes by triangulation relative positions of neighboring centers with the condition that the circumcircle through the triangle is free from other centers like the black circle in (b) below. This analysis is shown below as performed on the image shown at the top of the page.

We have developed software to analyze the patterns created by block copolymer thin films which can be downloaded here.

Wiesner Research Group - Cornell University

Software Overview and Walkthrough

This program will allow you to analyze repetitive pictures in microscopy images. After inputting the image, the program will first determine the pore centers (right) based on the topology (intensity) of the image (AFM in this case, left)

This analysis can be taken further to determine the number of nearest neighbors to each center in a field of interest. This analysis is plotted as a Voronoi diagram which represents connectivity as a function of color as shown below for the analyzed image.

Instructions to use IDL watershed program

Download watershed.zip
Download and install IDL VM
Unzip files into the RSI\IDLXX\watershed folder (where XX is the IDL version))
Run IDL VM or IDL
Write .run topostart in the command prompt
open watershed project by going to IDL toolbar and clicking File -> Open Project -> DI_watershed (IDL project file in watershed folder)
Ignore any error message that might appear at this point
Compile all files by clicking Project -> Compile -> All Files

Then click Project -> Run in the IDL toolbar
A new window will pop to File -> Open the desired flattened AFM image in binary format.
Press Calculate after making proper choice of primary and overlay image. For example, use bare SFM as primary image and use centers as overlay to find coordinates of centers in SFM.
The coordinates are saved as centers.txt in \RSI\IDLXX\watershed folder