Introduction[edit | edit source]
ImageJ is a Java-based program used for image processing and analysis. It can be used to determine packing factors (or void fraction) of nanocolumnar structures if top-down SEM images are available.
Protocol[edit | edit source]
- Open the top-down SEM image of the layer in ImageJ.
- Select Image - Type - 8-bit
- Thresholding: Select on Image - Adjust - Threshold
- Set dark background and ajust colours/threshold as appropriate - Click Apply once set (try to colour the tops of the columns, do not overestimate at this stage and compare with original picture)
- Select Process - Binary - Make Binary
- Closing: Select Process - Binary - Close
- Filling: Select Process - Binary - Fill Holes
- Watershed Maxima: Select Process - Binary - Watershed
- Particle Analysis: Select Analysis - Analyze Particles
- Recommended Settings: Size (10-infinity), Circularity 0.5-1 (only near circular shapes included), Display results, Summarize, Exclude on Edges
