Disclosed herein are systems and methods for automatically identifying and characterizing particles within an image. In particular, the systems and methods disclosed herein may be utilized to identify particles that overlap or form agglomerations of particles. Agglomerates may be identified using a variety of techniques. Perimeters of individual particles within an agglomerate may be estimated. According to several embodiments, objects may be characterized using a variety of characteristics, including the particle size, shape, Stokes diameter, aerodynamic diameter, convexity, circularity, and the like. In some instances, these characteristics may allow additional information to be calculated or determined, such as the composition of a particle. These characteristics may also be utilized to determine physical properties of particles, such as flowability, abrasive efficiency, bioactivity, solubility, catalytic activity, and other properties.