Restoring a degraded frame resulting from reconstruction of a source frame is described. A method includes generating, using first restoration parameters, a first guide tile for a degraded tile of the degraded frame, determining a projection parameter for a projection operation, and encoding, in an encoded bitstream, the first restoration parameters and the projection parameter. The projection operation relates differences between a source tile of the source frame and the degraded tile to differences between the first guide tile and the degraded tile.