Effect of Color Pre-Processing on Color-Based Object Detection

Color-based object detection is receiving much interest recently for the potential applications in the traffic and security fields. While Color information is precious to facilitate and accelerate the object detection process, the spectral sensitivity functions of the color camera sensor have a strong effect on the quality of image colors and their appearance in the Hue-Saturation, H-S histogram of the object surface color. In this work we study the effect of color preprocessing by using a linear spectral sharpening transform, on the quality of image colors and their detection quality. It is shown that color-based object detection is severely impaired due to the spectral overlap of camera filters. We show the performance of a new spectral sharpening method, running on real images. The image color preprocessing resulted in a significant reduction of color correlation and hence clearer image colors. The transformed colors allow for fine definition of color zones in the H-S diagram and consequently enhances the detection process.