1. A method of performing intra prediction coding with respect to a plurality of blocks included in an image frame, comprising: confirming whether a neighboring pixel that is referred to in an intra prediction of a block exists in a current image frame; if the neighboring pixel referred to in the intra prediction exists, reading a color difference signal value of the neighboring pixel referred to in the intra prediction from the current image frame; if the neighboring pixel referred to in the intra prediction does not exist, reading a color difference signal value of at least one pixel from a previous image frame that corresponds to the block of the current image frame; and performing the intra prediction with reference to the read color difference signal value of the neighboring pixel and the read color difference signal value of the at least one pixel.