This chapter compiles established practices for characterizing crystal populations to characterize the crystallization of biomolecules using image-based systems. It starts with an introduction to available measurement tools, comparing their advantages and disadvantages. This is followed by a detailed description of the different steps from image acquisition to data analysis and visualization, with considerations offered for each step. The chapter ends with a discussion of the challenges and limitations currently facing imaging tools. By providing a comprehensive overview of crystal characterization using imaging techniques, this chapter aims to equip practitioners with the knowledge necessary to effectively apply these methods in both research and industrial contexts.