Vector amplification for color-dependent image filtering

In previous work the authors have studied the problem of color-dependent linear vector image filtering, particularly based on resolution of pixel vectors into color-space directions parallel to and perpendicular to the color-space direction of a chosen color of interest (COI). A significant problem with this approach has been the lack of directional resolution, and consequent lack of good color-specificity in the resulting filters. In this paper for the first time we present an approach to increasing the directional resolution using a concept which we call vector amplification, that is, increasing the magnitude of pixel vectors close to the direction of the COI. The amplification is reversible, and thus it is possible to implement a filter by parallel/perpendicular resolution coupled with vector amplification; filtering of the image component in the direction parallel to the COI; and combination of the resolved components, coupled with vector attenuation.