RGB Compensation Based on Background Shadow Subtraction for Low-Luminance Pill Recognition

Pill color is applied as one of important features for pill recognition; however, most of pill color is white or cream. It's difficult to classify two similar color pills because pill's color is sensitive to luminance intensity. However, when its luminance intensity is increased, Y value of background is also increased but Y value of pill shadow is slightly decreased. Therefore, difference between Y value of background and its shadow is effectively represented luminance intensity. In this report, we propose RGB compensation based on background shadow subtraction to compensate luminance-intensity effect in RGB value. Experimental results confirm an effectiveness of our proposed compensation method.