An efficient method for robust gradient estimation of RGB color images

A new vector-wise scheme for the gradient estimation in noisy color images is proposed. In the color images, different types of noise may corrupt the image. To reduce the effect of noise in the gradient estimation, the distance weighted order statistic filter (DWOSF) is introduced, to be embedded in the gradient estimator. DWOSF is an order statistic filter in which the color outliers in a neighborhood are adaptively assigned smaller weights than the other pixels in that neighborhood. The simulation results show that the proposed method accurately estimates the true gradient vector in noisy RGB color images.