Color Compensation Based on Color Background Shadow for Pill Identification

Pill color is one of important features for automatic pill identification; however, it's difficult to clarify an exact color. Pill color is changed when luminance changes. Moreover, its color is changed because of white balance function in taken camera too. In this report, we propose a color compensation based on color background shadow for pill identification. To compensate pill color, “RGB” component of pill image is converted in term of “YIQ” component to separate between luminance intensity (“Y” value) and color component (“I” and “Q” values). “Y” value of the selected pill is compensated by “Y” value of its background, whereas “I” and “Q” values of the selected pill are compensated by “I” and “Q” values of its shadow. Experimental results confirm an effectiveness of our proposed compensation method.