This program (for python version 2.7 and 3.6) tracks flow velocities using image or frame sequences. It includes measuring the camera position and orientation (camera pose), automatic extraction of the water area for feature searching, particle detection and filtering, particle tracking and filtering and scaling the tracks to flow velocities. Furthermore, a function is included to automatically co-register frames in case of camera movements. The tool is solely updated for python version 3.6. How to cite: Eltner, A., Sardemann, H., Grundmann, J.: Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery. Hydrol. Earth Syst. Sci., 24, 1429–1445, 2020