An image enhancement technique using polynomial filters

A novel method for image enhancement based on polynomial filters is presented. Its structure is similar to the one of the unsharp masking technique, but in the sharpening path a set of parallel branches are used; each is formed by the cascade of a linear operator and a nonlinear one, which act orthogonally with respect to each other. In this way, it is possible to sense the presence of correlated image details (which are enhanced) or noise (which is attenuated). Some experimental trials show that the proposed method can over-perform more classical techniques in the enhancement of blurred and noisy images; this is visually apparent but is also confirmed by a simple but effective figure of merit.<>