# US 2014/0192876 A1 · Image encoding/decoding apparatus and method to which filter selection by precise units is applied > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192876 A1 - Document ID: US20140192876A1 - Status: Published application - Kind: A1 - Application number: 14/238,197 - Filed: 2012-08-16 - Published: 2014-07-10 - Earliest claimed: 2011-08-18 - Inventors: Chung Ku Yie; Min Sung Kim; Ui Ho Lee - Web page: https://patentgrep.com/patent/US20140192876A1 ## CPC - H04N 19/513: Processing of motion vectors - H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) - H04N 19/124: Quantisation - H04N 19/147: according to rate distortion criteria (rate-distortion as a criterion for motion estimation H04N19/567) - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/80: Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation (H04N19/635, H04N19/86 take precedence) - H04N 19/82: involving filtering within a prediction loop - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - 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 19/61: in combination with predictive coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract According to the present invention, an image encoding/decoding method involves selecting, for units which are more precise than picture units, interpolation filters to be used in a motion compensated inter prediction to calculate sub-pixel values, wherein said precise units include at least one of a slice unit and a partition unit. Thus, encoding precision may be improved in a high resolution image having high definition (HD) or greater resolution. ## Claims ### Claim 1 A method of encoding an image, the method comprising: generating a prediction unit for inter prediction of an input image; performing motion compensation inter prediction of the prediction unit; and selecting at least one of a filter used for the motion compensation inter prediction and an Adaptive Loop Filter (ALF) after a deblocking filter on a more precise unit basis than a picture unit. ### Claim 2 (depends on 1) The method of claim 1, wherein the more precise unit than the picture unit is a region unit smaller than the picture unit. ### Claim 3 (depends on 1) The method of claim 1, wherein the performing of motion compensation inter prediction comprises: dividing a partition of the prediction unit and performing block merging that merges samples belonging to a mergeable block set comprising peripheral samples of a present block with the present block; and selecting filter information of the filter used for the motion compensation inter prediction on the precise unit basis and calculating a subfixel value, wherein the filter information comprises at least one of a filter index and a filter coefficient. ### Claim 4 (depends on 3) The method of claim 3, wherein the same filter information is allocated to the merged block and is transmitted to a decoder, and the mergeable block set comprises at least one of blocks generated by block and geometrical partitioning generated by asymmetric partitioning. ### Claim 5 (depends on 1) The method of claim 1, wherein filter information of the ALF is included in a Picture Parameter Set, and on-off information of the ALF is included in each slice header. ### Claim 6 A method of decoding an image, the method comprising: entropy decoding received bitstream, performing inverse quantization and inverse transformation of a residual, and restoring the residual; generating a prediction unit using prediction unit information and a motion parameter; extracting encoded filter information by selecting on a more precise unit basis than a picture unit, wherein the filter information comprises at least one of a filter index and a filter coefficient; and restoring an image by adding a residual to the prediction unit in which inter prediction is performed by performing inter prediction of the prediction unit. ### Claim 7 (depends on 6) The method of claim 6, wherein the more precise unit than the picture unit is a region unit smaller than the picture unit. ### Claim 8 (depends on 6) The method of claim 6, wherein the extracted filter information is filter information of an Adaptive Loop Filter (ALF) after a deblocking filter, and the filter information is included in a picture parameter set, and on-off information of the ALF is included in each slice header. ### Claim 9 (depends on 6) The method of claim 6, wherein the filter coefficient is selected based on at least one of a bi-directional prediction mode, a single directional prediction mode, and pixel precision. ### Claim 10 (depends on 6) The method of claim 6, wherein after a partition of the prediction unit is divided, a present block and a merged block among blocks belonging to a mergeable block set have the same filter information. ### Claim 11 (depends on 6) The method of claim 6, wherein the filter information is filter information of a filter used for motion compensation inter prediction. ### Claim 12 (depends on 6) The method of claim 6, wherein the mergeable block set comprises at least one of blocks generated by block and geometrical partitioning generated by asymmetric partitioning. ### Claim 13 (depends on 6) The method of claim 6, wherein header information decoded through the entropy decoding comprises prediction unit information and a motion parameter and filter information for motion compensation and prediction. ### Claim 14 An image decoding apparatus, comprising: an inverse quantization unit and inverse transformation unit that perform inverse quantization and inverse transformation of a residual by entropy decoding received bitstream and that restore the residual; a motion compensation unit that generates a prediction unit using prediction unit information and a motion parameter; and an adder that restores an image by adding the residual to the prediction unit, wherein the image decoding apparatus extracts filter information encoded by selecting on a more precise unit basis than a picture unit, wherein the filter information comprises at least one of a filter index and a filter coefficient. ### Claim 15 (depends on 14) The image decoding apparatus of claim 14, wherein the more precise unit than the picture unit is a region unit smaller than the picture unit. ### Claim 16 (depends on 14) The image decoding apparatus of claim 14, wherein the extracted filter information is filter information of an Adaptive Loop Filter (ALF) after a deblocking filter, and the filter information is included in a picture parameter set, and on-off information of the ALF is included in each slice header. ### Claim 17 (depends on 14) is The image decoding apparatus of claim 14, wherein the filter coefficient is selected based on at least one of a bi-directional prediction mode, a single directional prediction mode, and pixel precision. ### Claim 18 (depends on 14) The image decoding apparatus of claim 14, wherein after a partition of the prediction unit is divided, a present block and a merged block among blocks belonging to a mergeable block set have the same filter information. ### Claim 19 (depends on 14) The image decoding apparatus of claim 14, wherein the mergeable block set comprises at least one of blocks generated by block and geometrical partitioning generated by asymmetric partitioning. ### Claim 20 (depends on 14) The image decoding apparatus of claim 14, wherein header information decoded through the entropy decoding comprises prediction unit information and a motion parameter and filter information for motion compensation and prediction.