Vector median filter(VMF)is a kind of traditional highly effective vector filter which is mainly used to remove impulsive noise from color images.But it fails to distinguish thin lines and boundaries from impulsive noise

and usually filter them out.This paper analyzes quaternion rotation theory and its applications to color image processing.Based on this analysis and by imitating Laplacian operators

a new color impulse detector is presented.Combining this color impulse detector with the traditional VMF

a new kind of switching vector median filters is proposed.The experimental results show that

compared with the traditional VMF and some of the representative vector filters and recently developed vector filters

uhe proposed approach

not only effectively preserves the fine details

but also provides better filtering performance.