A video decoding apparatus, comprising: a decoder for receiving encoded data to reconstruct a transformed and quantized frequency conversion block corresponding to a frequency conversion unit which is a unit of transforming residual signals; an inverse quantizer and inverse transformer for inversely quantizing and inversely transforming the transformed and quantized frequency conversion block to reconstruct a residual block; a predictor for predicting a current block to generate a predicted block; and an adder for adding the reconstructed residual block and the predicted block to reconstruct the current block, wherein the decoder reconstructs the transformed and quantized frequency conversion block in the unit of frequency regions divided from the frequency conversion unit, the frequency regions being equal-sized square blocks, by extracting, from the encoded data, frequency region encoding information indicating whether a frequency region corresponding thereto has at least one non-zero frequency coefficient, the extracted frequency region encoding information having a value of 0 or 1; extracting from the encoded data and inversely scanning frequency coefficients corresponding to the frequency region when the extracted frequency region encoding information has a value of 1 and thereby indicates that the frequency region has at least one non-zero frequency coefficient, and setting all frequency coefficients in the frequency region to 0, when the extracted frequency region encoding information has a value of 0 and thereby indicates that the frequency region does not have at least one non-zero frequency coefficient; wherein the frequency region encoding information is extracted from the encoded data by the unit of frequency region. a decoder for receiving encoded data to reconstruct a transformed and quantized frequency conversion block corresponding to a frequency conversion unit which is a unit of transforming residual signals; an inverse quantizer and inverse transformer for inversely quantizing and inversely transforming the transformed and quantized frequency conversion block to reconstruct a residual block; a predictor for predicting a current block to generate a predicted block; and an adder for adding the reconstructed residual block and the predicted block to reconstruct the current block, wherein the decoder reconstructs the transformed and quantized frequency conversion block in the unit of frequency regions divided from the frequency conversion unit, the frequency regions being equal-sized square blocks, by extracting, from the encoded data, frequency region encoding information indicating whether a frequency region corresponding thereto has at least one non-zero frequency coefficient, the extracted frequency region encoding information having a value of 0 or 1; extracting from the encoded data and inversely scanning frequency coefficients corresponding to the frequency region when the extracted frequency region encoding information has a value of 1 and thereby indicates that the frequency region has at least one non-zero frequency coefficient, and setting all frequency coefficients in the frequency region to 0, when the extracted frequency region encoding information has a value of 0 and thereby indicates that the frequency region does not have at least one non-zero frequency coefficient; wherein the frequency region encoding information is extracted from the encoded data by the unit of frequency region.