Compound color recognition via image analysis on high-throughput compound libraries

A new machine vision method is presented to detect micro tubes with colored solutions or undissolved compounds in solvents on screening plates used in drug discovery. The method presented herein takes an image of a 96 tubes micro tube rack as input. After applying edge detection on the input image, the circles that characterize the borders of the micro tubes are detected via shape matching. A gradient search is used to extract the colors from the micro tubes. Automatic calibration is applied to adapt to changing light conditions. Experiments with more than two thousand micro tube racks (approx. 170,000 compounds) compiled over three years showed that the method is fast and robust.