A simple digital image processing technique is examined to recognize the phase separation of a chemical process. A traditional aqueous-organic hexane (1) - water (2) - acetic acid (3) system and its alternative aqueous two-phase PEG (1)-K2HPO4 (2)-water (3) system was selected as the model system with or without polymer. In this technique, phase separation was monitored and recorded using a simple webcam set up and processed on a computer using an image subtraction process to determine the net change in the system. A program was written in Python using OpenCV programming language and an image subtraction process was performed to detect absolute changes over time from the recorded shot. The difference between the initial image and the aging image was evaluated. This digital image processing gave the recognition of the phase separation of both PEG (1)-K2HPO4 (2)-water (3) and hexane (1) - water (2) - acetic acid (3) systems regardless of phase separation duration.