Corneal endothelial cells of the human eye
This image analysis example came from a professor of medical school: "an image of corneal endothelial cell of the human eye. These cells do not regenerate so if cells are lost or damaged then neighbouring cells have to enlarge and often lose their normal hexagonal shape. We can digitally obtain an image of the cells with a specular microscope 1.2mm x 0.8mm we would like to obtain the differences in cell areas and if possible the departure from hexagonality."
A quick experiment with Pixcavator showed that this is feasible: all cells are captured and measured. The accuracy of the result should improve if you can improve the quality of the image. As for hexagonality, the roundness may (should?) serve as a substitute: for the cells compare their roundness to that of a regular hexagon.
The cell density is the total area divided by the number of cells. The number of cells is displayed, the total area is not (percentage is displayed in the current version). You can get it from the spreadsheet or you can use the average cell size (it is displayed) multiplied by the number of cells.
Other image analysis examples