Intra prediction encoding/decoding apparatus and method capable of skipping prediction mode information using the characteristics of reference pixels

PURPOSE: An intra prediction encoding/decoding apparatus capable of skipping prediction mode information using the characteristics of reference pixels is provided to omit the transmission of prediction mode information using the property of reference pixels. CONSTITUTION: A characteristic information calculation unit(510) selects one among reference pixels around a current block. The characteristic information outputs the characteristic information toward the directionality of the selected reference pixel. If the comparison result between the calculated property information and the set reference value satisfies the set condition, a prediction mode determination unit(530) determines the prediction mode about the current block as a mode corresponding to the selected reference pixel. An encoding unit(540) encodes the residual of the predicted block by the determined mode.