Subject area	Bioengineering and Materials Science
More specific subject area	Tissue Engineering and materials characterization
Type of data	Tables, images, graphs/figures, text files, picture document files
How data was acquired	Digitally generated images made using Inkscape graphics package. Scanning electron microscope images (SEM, Hitachi S4700 SEM, 5 kV, 10 mA, ≈13 mm working distance).
Data format	Raw, filtered, and analyzed
Experimental factors	All .svg files generated by Inkscape were converted to .tif files using ImageJ. All SEM images were first segmented using default algorithms in ImageJ as per the methods discussed in [1].
Experimental features	DiameterJ was written as a plugin for ImageJ and validated using images generated in Inkscape graphics package. Images were analyzed by other software packages and methods and results were compared with DiameterJ. Next, DiameterJ was used to assess SEM images of steel wires with a known diameter distribution. Other available software/methods were also used to analyze the steel wire images and results were compared to DiameterJ. SEM images of electrospun polymeric nanofiber were also analyzed with DiameterJ and other available software/methods, and results were compared. Finally, different segmentation algorithms were tested with DiameterJ to assess its robustness when analyzing images of different segmentation quality.
Data source location	Gaithersburg Maryland, United States. 39 °08′11.2“N 77 °13′09.3“W
Data accessibility	Data is Zipped within this article. Also the source code for DiameterJ can be found at https://github.com/NHotaling/DiameterJ