Adaptive unequal weight planar prediction

A device configured for calculating a final planar prediction in planar mode to predict pixel values for a current coding block having height H, width W, and a top-left (TL) pixel within the current coding block is defined by coordinates x=0 and y=0, the device comprising:

• one or more computer processors comprising instructions that, when executed, control the one or more computer processors to be configured for:
• receiving a video bitstream including encoded video data;
• from the encoded data, interpolating a horizontal predictor and a vertical predictor for a pixel in the current coding block;
• identifying a coding block size to determine whether to use equal weight or unequal weights to apply to each of the horizontal and vertical predictors for calculating a final planar prediction value P(x,y) by comparing the coding block size to a coding block size threshold in accordance with:
• if the coding block size is larger than the coding block size threshold, calculating the final planar prediction value P(x,y) using unequal weights applied to each of the horizontal and vertical predictors in accordance with P(x,y)=(A(x,y)*Ph(x,y)+B(x,y)*Pv(x,y)+c(x,y))/(D(x,y)), where A(x,y) and B(x,y) are position dependent weighting factors for the horizontal and vertical predictors, respectively, c(x,y) is a position dependent rounding factor, and D(x,y) is a position dependent scaling factor,
• else if the coding block size is smaller than the coding block size threshold, calculating the final planar prediction value P(x,y) using equal weights applied to each of the horizontal and vertical predictors in accordance with P(x,y)=(H*Ph(x,y)+W*Pv(x,y))/(2*H*W), where W is block width, and H is block height.