of encoding moving pictures using a plurality of quantization matrices the method involves selecting one of the plurality of quantization matrices in consideration of an at least one characteristics of an input image transforming the input image and quantizing the transformed input image using the selected quantization matrix application_number US 201213709713 A description reference will now be made in detail to the embodiments of the present invention examples of which are illustrated in the accompanying drawings wherein like reference numerals refer to the like elements throughout the embodiments are described below to explain the present invention by referring to the figures when it comes to encoding moving pictures pre treatment filtering is very important because it can increase the efficiency of encoding the moving pictures by removing noise from images while a conventional pre treatment filtering technique for removing noise from images is generally carried out in a spatial pixel block in the present invention a noise removal technique is carried out in a dct block in an apparatus for encoding moving pictures in the present invention an approximated generalized weiner filtering method is used for removing noise from images in the approximated generalized weiner filtering method weiner filtering is realized by taking advantage of fast unitary transformation such as a discrete cosine transform dct however a filtering method other than the approximated generalized weiner filtering method may be selectively used for carrying out filtering in a dct block fig2 is a block diagram of an approximated generalized weiner filter processing image data whose average.