An encoding method and decoding method, and a device implementing the same are provided. The encoding method obtains an intra prediction mode related to a current block from a video signal, obtains prediction samples of the current block by performing intra prediction on the current block based on the intra prediction mode, scans transform coefficients of the current block based on a scanning type of the current block, obtains dequantized transform coefficients of the current block by dequantizing the transform coefficients, obtains residual samples of the current block by performing an inverse-transform on the dequantized transform coefficients, the inverse-transform being performed in a horizontal direction and a vertical direction, reconstructs the current block using the residual samples and the prediction samples, and applies a deblocking filter on the reconstructed current block.