Method and device for filtering image using filter bank in image coding system

A method for filtering a reconstructed picture performed by an encoding device, according to the present invention, comprises the steps of: deriving first filter information for a target region of a reconstructed picture; selecting one among the derived first filter information and a second filter information included in the filter bank; and performing filtering on the target region in the reconstructed picture on the basis of the selected filter information, wherein, if the first filter information is selected, the filter bank is updated, and if the second filter information is selected, a filter index may be transmitted to a decoder. According to the present invention, the filtering of a reconstructed picture on the basis of the filter bank may be efficiently performed, and the amount of data allocated to the transmission/reception of filter information is reduced therethrough, consequently enabling the increase of compression and coding efficiency.