System and method for constructing a plane for planar prediction
A system and method of defining a plane for planar coding in JVET in which first and second lines can be defined based upon pixels in left-adjacent and top-adjacent coding units. In some embodiments, the least squares method can be employed to define the relevant lines. One point along each of the lines can then be identified and the y-intercepts of the two lines can be averaged to obtain a third point. The three points can then be used to identify and define a plane for planar coding in JVET.
1. A decoder that receives a bitstream indicating how a coding tree unit was partitioned into coding units according to a partitioning structure that allows nodes to be split into coding units according to a partitioning structure that includes a rectangular coding unit, the decoder comprising:
(a) at least one processor that decodes the coding tree units based upon said partitioning structure into coding units including said rectangular coding unit, where said bitstream includes a slice;
(b) a first sample that corresponds one of a set of side neighboring samples to a respective one of the coding units that is on a first line between a predicted sample of said respective one of the coding units and said first sample;
(c) a second sample that corresponds one of a set of top neighboring samples to said respective one of the coding units that is on a second line between said predicted sample of said respective one of the coding units and said second sample;
(d) wherein said first sample, said second sample, and said predicted sample are arranged to form a plane;
(e) wherein said first line is different than said second line;
(f) wherein said first line is free from being based upon any of the said set of side neighboring samples nor any samples along said first line, and said second line is free from being based upon any of said set of top neighboring samples nor any samples along said second line;
(g) wherein said predicted sample is based upon said first sample and said second sample.
2. A method for predicting pixel values, for encoding video by an encoder as part of a bitstream, each of which having a respective position x, y for a current rectangular coding unit based upon neighboring pixel locations on an upper side of the current coding unit and on a left side of the current coding unit of a bitstream that includes a slice the method configured to:
calculate a first predictor for a pixel in the current coding unit based upon a first value that is determined by a summation of (i) one plus y the summation of which is multiplied by a value of a pixel location of pixel locations on the left side of the current coding unit at a vertical position of the height of the coding unit, (ii) a height of the coding unit minus one minus y the summation of which is multiplied by a value of a pixel location of the pixel locations on the upper side of the current coding unit at horizontal position x, where the summation of (i) and (ii) is adjusted by a first predictor factor;
calculate a second predictor, different from the first predictor, for a pixel in the current coding unit based upon a second value that is determined by a summation of (i) one plus x the summation of which is multiplied by a value of a pixel location of pixel locations on the upper side of the current coding unit at a horizontal position of the width of the coding unit, (ii) a width of the coding unit minus one minus x the summation of which is multiplied by a value of a pixel location of the pixel locations on the left side of the current coding unit at vertical position y, where the summation of (i) and (ii) is adjusted by a second predictor factor;
derive a prediction pixel value from the sum of (i) the first predictor and (ii) the second predictor and (iii) an adjustment factor, the sum of which is modified by a scaling factor, and wherein a plurality of prediction pixel values make up a prediction unit.
3. A bitstream of compressed video data that includes a slice for predicting pixel values each of which having a respective position x, y for a current rectangular coding unit based upon neighboring pixel locations on an upper side of the current coding unit and on a left side of the current coding unit of a bitstream that includes a slice the method configured to:
said bitstream containing data suitable to calculate a first predictor for a pixel in the current coding unit based upon a first value that is determined by a summation of (i) one plus y the summation of which is multiplied by a value of a pixel location of pixel locations on the left side of the current coding unit at a vertical position of the height of the coding unit, (ii) a height of the coding unit minus one minus y the summation of which is multiplied by a value of a pixel location of the pixel locations on the upper side of the current coding unit at horizontal position x, where the summation of (i) and (ii) is adjusted by a first predictor factor;
said bitstream containing data suitable to calculate a second predictor, different from the first predictor, for a pixel in the current coding unit based upon a second value that is determined by a summation of (i) one plus x the summation of which is multiplied by a value of a pixel location of pixel locations on the upper side of the current coding unit at a horizontal position of the width of the coding unit, (ii) a width of the coding unit minus one minus x the summation of which is multiplied by a value of a pixel location of the pixel locations on the left side of the current coding unit at vertical position y, where the summation of (i) and (ii) is adjusted by a second predictor factor;
said bitstream containing data suitable to derive a prediction pixel value from the sum of (i) the first predictor and (ii) the second predictor and (iii) an adjustment factor, the sum of which is modified by a scaling factor, and wherein a plurality of prediction pixel values make up a prediction unit.
4. A method for predicting pixel values, for decoding video by a decoder as part of a bitstream, each of which having a respective position x, y for a current rectangular coding unit based upon neighboring pixel locations on an upper side of the current coding unit and on a left side of the current coding unit of a bitstream that includes a slice the method configured to:
calculate a first predictor for a pixel in the current coding unit based upon a first value that is determined by a summation of (i) one plus y the summation of which is multiplied by a value of a pixel location of pixel locations on the left side of the current coding unit at a vertical position of the height of the coding unit, (ii) a height of the coding unit minus one minus y the summation of which is multiplied by a value of a pixel location of the pixel locations on the upper side of the current coding unit at horizontal position x, where the summation of (i) and (ii) is adjusted by a first predictor factor;
calculate a second predictor, different from the first predictor, for a pixel in the current coding unit based upon a second value that is determined by a summation of (i) one plus x the summation of which is multiplied by a value of a pixel location of pixel locations on the upper side of the current coding unit at a horizontal position of the width of the coding unit, (ii) a width of the coding unit minus one minus x the summation of which is multiplied by a value of a pixel location of the pixel locations on the left side of the current coding unit at vertical position y, where the summation of (i) and (ii) is adjusted by a second predictor factor;
derive a prediction pixel value from the sum of (i) the first predictor and (ii) the second predictor and (iii) an adjustment factor, the sum of which is modified by a scaling factor, and wherein a plurality of prediction pixel values make up a prediction unit.