Modern imaging technology provides the ability to examine a broad array of subject properties at scales from nanometers to light-years. We can look inside the human body, and inside sub-cellular compartments. We can create images depicting x-ray density, fluorophore concentration, or water diffusivity. However, simply looking at images is often no longer sufficient, and quantification is required. In this tutorial we will show how to obtain quantitative measures of physical properties from images. Measurement precision and avoidance of bias will receive special attention. We will cover manual methods to estimate surface area, volume, length, and density, as well as algorithms to obtain precise measurements of those same properties given a segmentation of the objects in the image. We will also describe algorithms to estimate size distributions without requiring a segmentation. It is important to properly design the experiment before starting the imaging. To this end, we will discuss sampling of the population, selecting number and location of slices and fields of view to image, choosing imaging resolution, etc.
The tutorial assumes some basic knowledge of digital images, including concepts such as smoothing and segmentation. No advanced mathematics or programming skills will be needed.