A review of the current literature is performed to assess the state-of-the-art in image analysis of horizontal air-water two-phase plug and slug flow. The present review is motivated by the need to develop accurate non-intrusive measurement techniques for the determination of bubble propagation velocity. Review findings were separated into two categories: experimental considerations for image analysis and image processing techniques. Experimental considerations for image analysis focus on physical experimental equipment and techniques that could be used, while image processing techniques focus solely on the post-processing of obtained images. Existing image processing techniques were reviewed with the anticipation that they may be incorporated into the framework of existing commercial software, such as MATLAB.
