1. A method of reducing noise in an image, the method comprising: setting a plurality of pixels in the image as a reference patch, and setting target patches in the image corresponding to the reference patch, the reference patch having a center pixel; determining a similarity between the reference patch and the target patches; and removing noise from the center pixel in the reference patch based on pixel values of center pixels in the target patches by applying, via a kernel, a weight to the center pixels of the target patches based on the similarity between the reference patch and the target patches, the kernel being adaptively changed according to the reference patch.