What You See versus What You Get: Basics of Image Analysis

Fluorescence microscopy images are not just pictures; they are quantitative datasets composed of pixel (and voxel) intensity values acquired under defined optical and detector conditions. This paper outlines key factors that determine whether an image supports defensible analysis, including sampling in XY and Z, bit-depth and dynamic range, multichannel acquisition and metadata, and the distinction between raw grayscale data and display renderings shaped by LUTs and contrast scaling. Common processing steps such as filtering, thresholding, segmentation, and pixel classification are framed as measurement tools only when raw data are preserved in lossless formats. Ultimately, robust analysis is enabled upstream by experimental design, not rescued downstream.