Adaptive temporal filtering for alternate frame reference rendering

An apparatus for using an alternate frame reference (ARF), comprising:

• a memory;
• and
• a processor, the processor configured to execute instructions stored in the memory to:
• select an anchor frame and video frames, wherein
• the anchor frame comprises an anchor block, and
• the anchor block comprises an anchor pixel;
• identify, for the anchor block of the anchor frame, respective reference blocks in the video frames;
• determine, for the anchor pixel and using an anchor patch, respective distances between the anchor pixel and respective co-located reference pixels of the respective reference blocks, wherein
• the anchor patch comprises anchor patch pixels in a neighborhood of the anchor pixel, and
• a respective distance, of the respective distances, between the anchor pixel and a respective co-located reference pixel is determined using the anchor patch pixels and co-located reference pixels;
• determine, using the respective distances, respective weights;
• determine, using the respective weights, an ARF pixel that is co-located with the anchor pixel;
• and
• encode, in a compressed bitstream, the ARF.

An apparatus for decoding using an alternate frame reference (ARF), comprising:

• a memory;
• and
• a processor, the processor configured to execute instructions stored in the memory to:
• decode, from a compressed bitstream, the ARF, wherein an encoder generated the ARF by operations including:
• selecting an anchor frame and video frames, wherein
• the anchor frame comprises an anchor block, and
• the anchor block comprises an anchor pixel;
• identifying, for the anchor block of the anchor frame, respective reference blocks in the video frames;
• determining, for the anchor pixel and using an anchor patch, respective weights based on respective patch-based distances between the anchor pixel and respective co-located reference pixels of the respective reference blocks, wherein a patch-based distance tween the anchor pixel and a respective co-located reference pixel of a reference block of the respective reference blocks is determined using each patch pixel of patch pixels of the anchor patch and a corresponding reference pixel of the reference block, wherein the patch pixels are in a neighborhood of the anchor pixel;
• and
• determining, using the respective weights, an ARF pixel that is co-located with the anchor pixel;
• and
• decode, using the ARF, frames from the compressed bitstream.