An apparatus for decoding an image, the apparatus comprising: an entropy decoding unit configured to receive intra prediction information and one-dimensional, 1D, quantized transform coefficients from an image encoding device, and restore a quantized transform block using the 1D quantized transform coefficients; an intra prediction unit configured to restore an intra prediction mode from the intra prediction information and generate a prediction block according to the intra prediction mode; an inverse quantization/transform unit configured to inversely quantize and inversely transform the quantized block to generate a residual block; and an adding unit configured to add the residual block and the prediction block to generate an original block, characterized in that: the entropy decoding unit restores a plurality of sub-blocks by applying a first scan pattern determined according to the intra prediction mode to the 1D quantized transform coefficients and restores the quantized transform block by applying a second scan pattern determined according to the intra prediction mode to the plurality of sub-blocks if it is determined that a size of the quantized block is equal to or larger than 8x8, wherein the first scan pattern is the same as the second scan pattern, wherein, when the intra prediction mode is a horizontal mode, the second scan pattern is a vertical scan. an entropy decoding unit configured to receive intra prediction information and one-dimensional, 1D, quantized transform coefficients from an image encoding device, and restore a quantized transform block using the 1D quantized transform coefficients; an intra prediction unit configured to restore an intra prediction mode from the intra prediction information and generate a prediction block according to the intra prediction mode; an inverse quantization/transform unit configured to inversely quantize and inversely transform the quantized block to generate a residual block; and an adding unit configured to add the residual block and the prediction block to generate an original block, characterized in that: the entropy decoding unit restores a plurality of sub-blocks by applying a first scan pattern determined according to the intra prediction mode to the 1D quantized transform coefficients and restores the quantized transform block by applying a second scan pattern determined according to the intra prediction mode to the plurality of sub-blocks if it is determined that a size of the quantized block is equal to or larger than 8x8, wherein the first scan pattern is the same as the second scan pattern, wherein, when the intra prediction mode is a horizontal mode, the second scan pattern is a vertical scan. the entropy decoding unit restores a plurality of sub-blocks by applying a first scan pattern determined according to the intra prediction mode to the 1D quantized transform coefficients and restores the quantized transform block by applying a second scan pattern determined according to the intra prediction mode to the plurality of sub-blocks if it is determined that a size of the quantized block is equal to or larger than 8x8, wherein the first scan pattern is the same as the second scan pattern, wherein, when the intra prediction mode is a horizontal mode, the second scan pattern is a vertical scan.