1. A method for processing of coded video using in-loop processing, the method comprising: receiving reconstructed video data corresponding to coded video data from a processing unit, wherein the reconstructed video data is divided into regions, and wherein a merge syntax is used to indicate whether a current region shares a same in-loop filter of a neighboring region of the current region; applying in-loop processing to the current region to generate a filtered region, wherein said applying in-loop processing uses the same in-loop filter of the neighboring region and the current region shares all parameters of the same in-loop filter of the neighboring region if the merge syntax indicates that the current region shares the same in-loop filter of the neighboring region, wherein the merge syntax comprises a 1-bit merge flag to indicate whether the current region shares the same in-loop filter of the neighboring region of the current region, wherein the regions are rectangular, the regions in a same row of a picture have a same height and the regions in a same column of the picture have a same width, wherein each of the regions not in top boundary and not in left boundary of the picture has exactly one left neighboring region and one upper neighboring region, the merge syntax further comprises a 1-bit merge candidate flag for the regions not in the top boundary and not in the left boundary of the picture to indicate whether the neighboring region merged is said exactly one left neighboring region or said exactly one upper neighboring region of the current region; and providing the filtered region.