Methods and Apparatus of Fractional Block Vectors in Intra Block Copy and Intra Template Matching for Video Coding

An apparatus for video coding, the apparatus comprising one or more electronics or processors arranged to:

• receive input data associated with a current block, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side, and wherein the current block is coded in IBC (Intra Block Copy) mode;
• when a current BV (Block Vector) for the current block is a fractional BV, generate a predictor, wherein prediction samples of the predictor are generated by applying an interpolation filter to reference samples as identified according to the current BV and a location of the current block, and wherein if a target reference sample for the interpolation filter is unavailable, a padded or copied sample is used or the current BV is modified so that all the reference samples for the interpolation filter are available;
• and
• encode or decode the current block using the predictor.

A method of video coding, the method comprising:

• receiving input data associated with a current block, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side, and wherein the current block is coded in IBC (Intra Block Copy) mode or IntraTMP (Intra Template Matching Prediction) mode;
• deriving a refined current BV (Block Vector) of current block based on a base BV derived from an IBC merge mode list, or based on a base BV of an IntraTMP coded block, wherein the refined current BV is allowed to use fractional accuracy;
• generating a predictor using information comprising the refined current BV;
• and
• encoding or decoding the current block using the predictor.

An apparatus for video coding, the apparatus comprising one or more electronics or processors arranged to:

• receive input data associated with a current block, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side, and wherein the current block is coded in IBC (Intra Block Copy) mode or IntraTMP (Intra Template Matching Prediction) mode;
• derive a refined current BV (Block Vector) of current block based on a base BV derived from an IBC merge mode list, or based on a base BV of an IntraTMP coded block, wherein the refined current BV is allowed to use fractional accuracy;
• generate a predictor according to the refined current BV;
• and
• encode or decode the current block using the predictor.