Video frame rate conversion method supporting replacement of motion-compensated frame interpolation with linear combination of frames and device implementing the same

A device for performing video frame rate conversion (FRC) supporting partial or complete replacement of motion-compensated frame interpolation with a linear combination of adjacent reference frames, the device comprising:

• a processor configured to execute stored instructions, to:
• obtain at least one pair of frames of a video which are subject to FRC;
• partition each frame of the at least one pair of frames into a plurality of blocks;
• estimate motion between the frames on a block-by-block basis to obtain:
• a forward motion field comprising a set of first motion vectors, wherein each first motion vector from among the set of first motion vectors corresponds to a first block from among a plurality of first blocks of a first frame of the at least one pair of frames, and points to a corresponding area in the second frame, and
• a backward motion field comprising a set of second motion vectors, wherein each second motion vector from among the set of second motion vectors corresponds to a second block from among a plurality of second blocks of a second frame, and points to a corresponding area in the first frame, and wherein the each first motion vector the each second motion vector is assigned a corresponding value of a motion estimation metric, the first frame preceding the second frame in time;
• obtain occlusions comprising covered occlusions, uncovered occlusions, and inconsistent occlusions based on the forward motion field and the backward motion field;
• and
• calculate an artifact probability metric indicating a probability of an appearance of an artifact in the motion-compensated frame interpolation between the first frame and the second frame, wherein the calculating comprises:
• detecting breaks between spatially adjacent motion vectors in at least one of the forward motion field and the backward motion field,
• processing the breaks by suppressing breaks which overlap only with the uncovered occlusions for breaks in the backward motion field or only with the covered occlusions for breaks in the forward motion field, and amplifying breaks which overlap with the inconsistent occlusions, and
• suppressing the breaks between the spatially adjacent motion vectors based on values of the motion estimation metric,
• performing smoothing filtering on the artifact probability metric, and
• obtaining one or more intermediate frames based on values of the smoothed artifact probability metric, and
• wherein the suppressing of the breaks comprises multiplying a corresponding value of the artifact probability metric by a weighting factor having a range [0,1], which decreases as a maximum value of the values of the motion estimation metric in a considered pair of motion vectors increases, reaching a value zero based on a first predetermined threshold value of the motion estimation metric being reached, and increases as the maximum value of the values of the motion estimation metric in the considered pair of motion vectors decreases, reaching a value of one based on a second predetermined threshold value of the motion estimation metric being reached.