FourierDCTFilter

FourierDCTFilter[image,t] reduces noise in image by locally thresholding the discrete cosine transforms of overlapping subimages, using the hard threshold t.

Examples

Reduce noise in an image:

noisyImg = ImageAdd[ExampleData[{"TestImage", "Lena"}], RandomImage[{-0.1, 0.1}, {512, 512}]];
FourierDCTFilter[noisyImg, 0.1]
(* Image[...] *)

Please visit the official Wolfram Language Reference for more details.