1. An image processing system comprising a processor, comprising: a first processing section which sets an area including a plurality of pixels while gradually moving the area in a road image captured by an imaging means mounted on a vehicle; a second processing section which corrects a color component of a first pixel included in the front end of the area in a moving direction among the plurality of pixels included in the area by the first processing section with reference to a corresponding color component of a second pixel other than the first pixel among the plurality of pixels; a third processing section, executed via the processor, which calculates a feature value of the first pixel that depends on a noticeable color on the basis of the color component of the first pixel corrected by the second processing section; and a fourth processing section which recognizes a lane mark having the noticeable color in the road image on the basis of feature values of a plurality of pixels obtained by sequentially repeating the correction of a color signal of the first pixel by the second processing section and the calculation of the feature value of the first pixel by the third processing section whenever the area is set by the first processing section; wherein the area is adjusted based upon the result of the correction of the color component of the first pixel.