Nanomaterials are characterized by their nanoscale dimensions which often determine the properties of nanomaterials. Therefore, by simply changing the dimensions, one can produce new functional materials. However, precise control of nanoscale dimensions in a nanomaterial synthesis process is very challenging because the underlying mechanism of the dimension changing process is not well understood. Recently, in situ electron microscopy has shown promise for direct, real-time imaging of the process. The issue still remains of how to analyze a large volume of microscope image data to track down individual events in time lapsed images and understand their effect on macroscopic dimension changes of nanomaterials over time. In this talk, we discuss related research issues and present a big data framework that addresses the issues, including in-line image understanding, real-time event tracking, and longitudinal and cross sectional analysis of the events over time.