The workflow. ExtractGC is based upon an easy to use, yet productive workflow for quickly obtaining GC size and volume statistics at the lab bench. Given a set of confocal microscopy images, pyBioImage provides the option of direct visualization, image mosaic construction, or direct analysis with the ExtractGC module. An automatic optimization algorithm iteratively selects the best input parameters for extracting GC volumes. From the output of the analysis, the user may interact with the data via a 3D visualization.