# US 2020/0288153 A1 · Apparatus, a method and a computer program for video coding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288153 A1 - Document ID: US20200288153A1 - Status: Published application - Kind: A1 - Application number: 16/882,199 - Filed: 2020-05-22 - Published: 2020-09-10 - Earliest claimed: 2010-02-08 - Assignees: Nokia Technologies Oy - Applicants: Nokia Technologies Oy - Inventors: Jani LAINEMA; Kemal UGUR - Web page: https://patentgrep.com/patent/US20200288153A1 ## CPC - H04N 19/182: the unit being a pixel - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction - H04N 19/107: between spatial and temporal predictive coding, e.g. picture refresh - H04N 19/11: among a plurality of spatial predictive coding modes - H04N 19/196: being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513) - H04N 19/197: {including determination of the initial value of an encoding parameter (H04N19/56 takes precedence)} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract There is disclosed an apparatus, a method and a computer program for video coding. The apparatus comprises a selector configured for selecting a pixel for prediction; a projection definer configured for determining a projection of said pixel to a set of reference pixels; and a prediction definer configured for selecting one or more reference pixels from said set of reference pixels on the basis of said projection, and using said selected one or more reference pixels to obtain a prediction value for said pixel to be predicted. ## Claims ### Claim 1 An apparatus comprising at least a processor, and a memory associated with said processor and having computer coded instructions stored therein, said instructions when executed by the processor causing the apparatus to perform: selecting a pixel of a current block for intra prediction; determining a set of reference pixels, wherein the set of reference pixels for the current block is already encoded pixels on a row above the current block and on a column left of the current block; determining a projection of said pixel to the set of reference pixels based on a displacement measure expressed with reference to a pixel on a last column and a last row of the current block; selecting a plurality of reference pixels from the set of reference pixels on the basis of said projection, wherein the plurality of reference pixels selected from the set of reference pixels are on the row above the current block for at least one pixel of the current block and are on the column left of the current block for at least one other pixel of the current block; and obtaining a prediction value for the pixel to be predicted based upon the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the displacement measure is expressed with reference to the pixel on the last column and the last row of the current block and a row or column of the set of reference pixels. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the apparatus is caused to determine the projection of said pixel to the set of reference pixels by being caused to determine the projection to a line of reference pictures, and wherein the apparatus is caused to obtain the prediction value by being caused to utilize distance of the projection from the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 4 (depends on 1) The apparatus of claim 1, further comprising computer instructions causing the apparatus to perform: determining a directionality value for the current block of pixels. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising computer instructions causing the apparatus to perform: encoding information indicative of the projection and intra-encoding method into a bit stream. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein an image comprises at least four blocks of pixels in two or more rows and in two or more columns, each block of pixels comprising at least two rows of pixels and two columns of pixels, the apparatus further comprising computer instructions causing the apparatus to perform encoding the image block-wise from left to right and from top to bottom, and determining the projection on the basis of the pixel at the lower right corner of the block as a control point. ### Claim 7 A method comprising: selecting, using a processor, a pixel of a current block for intra prediction; determining a set of reference pixels, wherein the set of reference pixels for the current block is already encoded pixels on a row above the current block and on a column left of the current block; determining a projection of said pixel to the set of reference pixels based on a displacement measure expressed with reference to a pixel on a last column and a last row of the current block; selecting a plurality of reference pixels from the set of reference pixels on the basis of said projection, wherein the plurality of reference pixels selected from the set of reference pixels are on the row above the current block for at least one pixel of the current block and are on the column left of the current block for at least one other pixel of the current block; and obtaining a prediction value for the pixel to be predicted based on the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 8 (depends on 7) The method of claim 7, wherein the displacement measure is expressed with reference to the pixel on the last column and the last row of the current block and a row or column of the set of reference pixels. ### Claim 9 (depends on 7) The method of claim 7, wherein determining the projection of said pixel to the set of reference pixels comprises determining the projection to a line of reference pictures, and wherein obtaining the prediction value comprises utilizing distance of the projection from the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 10 (depends on 7) The method of claim 7, further comprising: determining a directionality value for the current block of pixels. ### Claim 11 (depends on 7) The method of claim 7, further comprising: encoding information indicative of the projection and the selected encoding method into a bit stream. ### Claim 12 (depends on 7) The method of claim 7, wherein an image comprises at least four blocks of pixels in two or more rows and in two or more columns, each block of pixels comprising at least two rows of pixels and two columns of pixels, the method further comprising: determining the projection on the basis of the pixel at the lower right corner of the block as a control point. ### Claim 13 A computer program product comprising a non-transitory computer readable storage medium having computer coded instructions stored therein, said instructions when executed by a processor cause an apparatus to: select a pixel of a current block for intra prediction; determine a set of reference pixels, wherein the set of reference pixels for the current block is already encoded pixels on a row above the current block and on a column left of the current block; determining a projection of said pixel to the set of reference pixels based on a displacement measure expressed with reference to a pixel on a last column and a last row of the current block; select a plurality of reference pixels from the set of reference pixels on the basis of said projection, wherein the plurality of reference pixels selected from the set of reference pixels are on the row above the current block for at least one pixel of the current block and are on the column left of the current block for at least one other pixel of the current block; and obtain a prediction value for the pixel to be predicted based on the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 14 (depends on 13) The computer program product of claim 13, wherein the displacement measure is expressed with reference to the pixel on the last column and the last row of the current block and a row or column of the set of reference pixels. ### Claim 15 (depends on 13) The computer program product of claim 13, wherein the instructions cause the apparatus to determine the projection of said pixel to the set of reference pixels by determining the projection to a line of reference pictures, and wherein the instructions cause the apparatus to obtain the prediction value by utilizing distance of the projection from the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 16 (depends on 13) The computer program product of claim 13, wherein said instructions further cause the apparatus to determine a directionality value for the current block of pixels. ### Claim 17 (depends on 13) The computer program product of claim 13, wherein said instructions further cause the apparatus to encode information indicative of the projection and the selected encoding method into a bit stream. ### Claim 18 (depends on 13) The computer program product of claim 13, wherein an image comprises at least four blocks of pixels in two or more rows and in two or more columns, each block of pixels comprising at least two rows of pixels and two columns of pixels, and wherein said instructions further cause the apparatus to determine the projection on the basis of the pixel at the lower right corner of the block as a control point. ### Claim 19 An apparatus, comprising: an analyzer configured to examine an indication of a directionality regarding a current block of pixels of an image to be decoded with the current block including a pixel to be intra predicted; and a reconstructor configured to: determine a set of reference pixels, wherein the set of reference pixels for the current block is already decoded pixels on a row above the current block and on a column left of the current block; determine a projection of said pixel to the set of reference pixels based on a displacement measure expressed with reference to a pixel on a last column and a last row of the current block; select a plurality of reference pixels from the set of reference pixels on the basis of said projection, wherein the plurality of reference pixels selected from the set of reference pixels are on the row above the current block for at least one pixel of the current block and are on the column left of the current block for at least one other pixel of the current block; and obtain a prediction value for the pixel to be predicted based on the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the reconstructor is configured to determine the projection of said pixel to the set of reference pixels by being configured to determine the projection to a line of reference pictures, and wherein the reconstructor is configured to obtain the prediction value by being configured to utilize distance of the projection from the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 21 (depends on 19) The apparatus of claim 19, wherein the displacement measure is expressed with reference to the pixel on the last column and the last row of the current block and a row or column of the set of reference pixels. ### Claim 22 (depends on 19) The apparatus of claim 19, further configured to receive an indication of the projection. ### Claim 23 A method, comprising: examining an indication of a directionality regarding a current block of pixels of an image to be decoded with the current block including a pixel to be intra predicted; determining, using a processor, a set of reference pixels, wherein the set of reference pixels for the current block is already decoded pixels on a row above the current block and on a column left of the current block; determining a projection of said pixel to the set of reference pixels based on a displacement measure expressed with reference to a pixel on a last column and a last row of the current block; selecting a plurality of reference pixels from the set of reference pixels on the basis of said projection, wherein the plurality of reference pixels selected from the set of reference pixels are on the row above the current block for at least one pixel of the current block and are on the column left of the current block for at least one other pixel of the current block; and obtaining a prediction value for the pixel to be predicted based on the plurality of reference pixels selected from the set of reference pixels. ### Claim 24 (depends on 23) The method of claim 23, wherein determining the projection of said pixel to the set of reference pixels comprises determining the projection to a line of reference pictures, and wherein obtaining the prediction value comprises utilizing distance of the projection from the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 25 (depends on 23) The method of claim 23, wherein the displacement measure is expressed with reference to the pixel on the last column and the last row of the current block and a row or column of the set of reference pixels. ### Claim 26 (depends on 23) The method of claim 23, further comprising receiving an indication of the projection. ### Claim 27 A computer program product comprising a non-transitory computer readable storage medium having computer coded instructions stored therein, said instructions when executed by a processor cause an apparatus to: examine an indication of a directionality regarding a current block of pixels of an image to be decoded with the current block including a pixel to be intra predicted; determine a set of reference pixels, wherein the set of reference pixels for the current block is already decoded pixels on a row above the current block and on a column left of the current block; determine a projection of said pixel to the set of reference pixels based on a displacement measure expressed with reference to a pixel on a last column and a last row of the current block; select a plurality of reference pixels from the set of reference pixels on the basis of said projection, wherein the plurality of reference pixels selected from the set of reference pixels are on the row above the current block for at least one pixel of the current block and are on the column left of the current block for at least one other pixel of the current block; and obtain a prediction value for the pixel to be predicted based upon the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 28 (depends on 27) The computer program product of claim 27, wherein the instructions that cause the apparatus to determine the projection of said pixel to the set of reference pixels comprise instructions configured to cause the apparatus to determine the projection to a line of reference pictures, and wherein the instructions that cause the apparatus to obtain the prediction value comprise instructions configured to cause the apparatus to utilize distance of the projection from the plurality of reference pixels that were selected from the set of reference pixels. ### Claim 29 (depends on 27) The computer program product of claim 27, wherein the displacement measure is expressed with reference to the pixel on the last column and the last row of the current block and a row or column of the set of reference pixels. ### Claim 30 (depends on 27) The computer program product of claim 27, wherein said instructions further cause the apparatus to receive an indication of the projection.