Screener Evaluation of Pseudo-Colored Single Energy X-Ray Luggage Images

Abstract

An interactive user friendly graphical user interface and a portable test were developed and used in a performance evaluation study involving a population of actual federal airport screeners. The paper describes a series of linear and non-linear pseudo-coloring maps designed and applied to single energy x-ray luggage scans, to assist airport screeners in identifying and detecting threat items, particularly hard to see low-density weapons in luggage. Considerations of the psychological and physiological processing involved in the human perception of color as well as the effects of using various color models and color transforms were explored. Statistical analysis of screeners' evaluation results proved the advantages of using color over gray level data and also allowed the ranking of color maps and selection of the best performing coloring scheme. Rate improvements in weapon detection of up to 97% were achieved through the use of color.