to a chroma component block deciding a transform skip mode of the chroma component block from a plurality of transform skip mode candidates according to the prediction mode that corresponds to the chroma component block and reverse transforming the chroma component block on the basis of the transform skip mode that is decided application_number US 201514605302 A description although elements illustrated in the drawings are independently shown so as to represent different distinctive functions in a video encoding apparatus decoding apparatus such a configuration does not indicate that each element is constructed by a separate hardware constituent or software constituent that is the elements are independently arranged for convenience of description wherein at least two elements may be combined into a single element or a single element may be divided into a plurality of elements to perform functions it is to be noted that embodiments in which some elements are integrated into one combined element and or an element is divided into multiple separate elements are included in the scope of the present invention without departing from the essence of the present invention hereinafter exemplary embodiments of the invention will be described in detail with reference to the accompanying drawings like reference numerals in the drawings refer to like elements throughout and redundant descriptions of like elements will be omitted herein fig1 is a.