Restoration for video coding with self-guided filtering and subspace projection

A non-transitory computer-readable storage medium having stored thereon an encoded bitstream encoded by a processor, wherein the encoded bitstream comprises:

• an index into a codebook containing sets of restoration parameters, the index corresponding to first restoration parameters for generating a first guide frame Y1 and second restoration parameters for generating a second guide frame Y2 for a degraded frame Y, wherein the first restoration parameters include a first radius value r1 and a first noise value e1, and the second restoration parameters include a second radius value r2 and a second noise value e2;
• and
• a first projection parameter α and a second projection parameter β for use in a projection operation to generate a reconstructed frame YR,
• wherein the projection operation is based on α(Y1−Y)+β(Y2−Y),
• wherein the encoded bitstream is configured for decoding by operations that include restoring the degraded frame Y using the first guide frame Y1, the second guide frame Y2, and the projection operation,
• wherein the first guide frame Y1 is generated by calculating, for each pixel of the degraded frame Y, a mean and a variance in a window of size (2r1+1)×(2r1+1) centered at the pixel, and
• wherein the mean, the variance, and the first noise value e1used to determine a guide pixel.

A non-transitory computer-readable storage medium having stored thereon an encoded bitstream configured for decoding by a processor, wherein the encoded bitstream comprises:

• a frame header including data elements for decoding:
• a first projection parameter a and a second projection parameter β, wherein the first projection parameter a and the second projection parameter β used in a projection operation based on a (Y1−Y)+β(Y2−Y) to restore a degraded frame Y, where Y1 is a first guide frame generated using first restoration parameters, and where Y2 is a second guide frame generated using second restoration parameters, wherein the first restoration parameters include a first radius value r1 and a first noise value e1, and the second restoration parameters include a second radius value r2 and a second noise value e2, and wherein the data elements in the frame header directly encode the first radius value r1, the first noise value e1, the second radius value r2, and the second noise value e2;
• the first restoration parameters and the second restoration parameters for generating the first guide frame and the second guide frame, respectively,
• the first guide frame Y1 generated by calculating, for each pixel of the degraded frame Y, a mean and a variance in a window of size (2r1+1)×(2r1+1) centered at the pixel, and
• the mean, the variance, and the first noise value e1 used to determine a guide pixel.