OLYMPUS Stream is described as 'image analysis software guides users through all the steps for image acquisition, quantitative measurements, reporting, and advanced materials science inspection tasks'. There are three alternatives to OLYMPUS Stream for Windows, Linux and Mac. The best alternative is ImageJ, which is both free and Open Source. Other great apps like OLYMPUS Stream are MountainsMap (Paid) and SPIP™ (Paid).
ImageJ is a public domain, Java-based image processing program developed at the National Institutes of Health. ImageJ was designed with an open architecture that provides extensibility via Java plugins and recordable macros.