Abstract: Disclosed is an in-loop filtering method according to an adaptive pixel classification standard. The in-loop filtering method according to an adaptive pixel classification standard in a video decoding apparatus comprises the steps of: classifying reconstructed samples according to an absolute or relative classification standard; acquiring offset data on the basis of results of classifying the reconstructed samples; adding an offset value to the reconstructed samples by referencing the acquired offset data; and outputting the offset value-added reconstructed samples. Accordingly, errors in the reconstructed image can be corrected.