System and method for motion compensation in video coding

A user equipment, comprising:

• an encoder comprising processing circuitry configured to:
• utilize two-dimensional separable interpolation filters, each of the two-dimensional separable interpolation filter split into two two-dimensional filters applied in horizontal and vertical directions,
• select, from among a plurality of vertical interpolation filters, one of a vertical one-dimensional filter or a vertical two-dimensional filter,
• select, from among a plurality of horizontal interpolation filters, one of a horizontal one-dimensional filter or a horizontal two-dimensional filter,
• use the selected vertical and horizontal interpolation filters to generate at least one pixel value by interpolating pixels of a pixel block, and
• perform prediction encoding using the at least one pixel value to generate an encoded bitstream of video;
• and
• a transceiver configured to send the encoded bitstream of video,
• wherein the horizontal two-dimensional filter for horizontal interpolation is defined as:
• H
• =
• [
• α
• 1
• ⁢
• h
• 1
• α
• 2
• ⁢
• h
• 2
• ⋮
• α
• N
• ⁢
• h
• N
• ]
• ,
• where α1, α2, . . . , αN are scalar values, h1, h2, . . . , hN are one-dimensional filters of at most length N, where h1, h2, . . . , hN are each selected to include a phase shift of θ, and where α1, 60 2, . . . , αN are selected to include a phase shift of 0.

A method for decoding an encoded bitstream of video, the method comprising:

• receiving the encoded bitstream of video including a pixel block;
• utilizing two-dimensional separable interpolation filters, each of the two-dimensional separable interpolation filters split into two two-dimensional filters applied in horizontal and vertical directions;
• selecting, from among a plurality of vertical interpolation filters, one of a vertical one-dimensional filter or a vertical two-dimensional filter;
• selecting, from among a plurality of horizontal interpolation filters, one of a horizontal one-dimensional filter or a horizontal two-dimensional filter;
• using the selected vertical and horizontal interpolation filters to generate at least one pixel value by interpolating pixels of the pixel block;
• and
• performing prediction decoding using the at least one pixel value to restore the video,
• wherein the horizontal two-dimensional filter for horizontal interpolation is defined as:
• H
• =
• [
• α
• 1
• ⁢
• h
• 1
• α
• 2
• ⁢
• h
• 2
• ⋮
• α
• 𝒩
• ⁢
• h
• 𝒩
• ]
• ,
• where α1, α2, . . . , αN are scalar values, h1, h2, . . . , hN are one-dimensional filters of at most length N, where h1, h2, . . . , hN are each selected to include a phase shift of θ, and where α1, α2, . . . , αN are selected to include a phase shift of 0.