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 frame; if the neighboring pixel referred to in the intra prediction exists, reading a color difference signal value of the pixel referred to in the intra prediction from the current image frame; if at least one neighboring pixel referred to in the intra prediction does not exist, reading the color difference signal value of at least one pixel from a previous image frame; and performing the intra prediction with reference to the read color difference signal value of the pixel.