Multiphase flow measurement is a very challenging issue in process industry. One of the promising approaches for multiphase flow analysis is image processing. Image segmentation is very important step in multiphase flow analysis. Determination of appropriate threshold value is very critical step for correct identification of the liquid and gas phases. There are two main thresholding techniques: Global and Adaptive. Adaptive thresholding is more suitable for multiphase flow case due to it’s adaptability to image conditions such non-uniform illumination and noise. In this work, six adaptive thresholding techniques are examined for the case of wavy flow regime. These algorithms are used to estimate the wave shape and mix region between liquid and gas. In general, the adaptive algorithms are able to compensate for non-uniform illumination and they are able to estimate wave shape and mix region correctly. The execution time for the adaptive techniques is higher than global thresholding technique, but with the availability of new powerful PCs, it will become a minor issue.