# US 10,484,687 B2 · Method and apparatus for image encoding and decoding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,484,687 B2 - Document ID: US10484687B2 - Status: Granted - Kind: B2 - Application number: 15/870,230 - Filed: 2018-01-12 - Published: 2018-10-04 - Granted: 2019-11-19 - Earliest claimed: 2017-04-04 - Assignees: Electronics and Telecommunications Research Institute - Applicants: Electronics and Telecommunications Research Institute - Inventors: Soon Heung Jung; Myung Seok Ki; Hui Yong Kim; Joo Young Lee; Se Yoon Jeong; Jin Soo Choi - Web page: https://patentgrep.com/patent/US10484687B2 ## CPC - H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking - H04N 19/137: Motion inside a coding unit, e.g. average field, frame or block difference - H04N 19/154: Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion (use of rate-distortion criteria H04N19/147) - H04N 19/172: the region being a picture, frame or field - H04N 19/587: involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence - H04N 19/59: involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Disclosed is a method and apparatus for encoding/decoding an image. The image encoding apparatus according to an embodiment of the present disclosure may include: an encoding level decision unit determining an encoding level of an input image; a sampling unit outputting an encoding target picture associated with the encoding level determined in the encoding level decision unit; an encoding unit encoding the encoding target picture output from the sampling unit; a reference picture storage unit storing at least one reference picture; and a reconstructed image generation unit generating a reconstructed image corresponding to the input image in association with the encoding level determined in the encoding level decision unit. ## Claims ### Claim 1 An image encoding apparatus comprising: an encoding level decision unit, configured to determine an encoding level of an input image respectively; a sampling unit, configured to construct an encoding target picture associated with the encoding level determined in the encoding level decision unit and output the encoding target picture; an encoding unit, configured to encode the encoding target picture output from the sampling unit; and a reconstructed image generation unit, configured to generate a first reconstructed image corresponding to the input image in association with the encoding level and at least one second reconstructed image corresponding to at least one pre-determined resolution; and a reference picture storage unit storing the first reconstructed image and the at least one second reconstructed image as a reference picture, wherein the encoding level decision unit determines whether or not to skip the input image and a spatial resolution transform of the input image by considering a quality of the first reconstructed image corresponding to the input image being encoded. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the encoding level decision unit comprises: a frame skip decision unit configured to determine whether or not to skip the input image; and a resolution decision unit configured to determine a spatial resolution transform of the input image. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the reconstructed image generation unit is configured to generate the first reconstructed image corresponding to a skipped input image using at least one of an image obtained by duplicating a previous encoded input image, and a reconstruction image reconstructed by considering a temporal relationship between at least two previous encoded input images and the skipped input image. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the reconstructed image generation is configured to transform the resolution of the first reconstructed image to the at least one pre-determined resolution and generate the at least one second reconstructed image corresponding to the at least one pre-determined resolution. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the encoding unit comprises: a first encoder configured to encode a first encoding target picture corresponding to an original resolution of the input image; and a second encoder configured to encode a second encoding target picture obtained by down-sampling the input image to a pre-determined resolution. ### Claim 6 (depends on 5) The apparatus of claim 5, further comprising a reference picture storage unit, configured to store at least one reference picture, wherein the reference picture storage unit comprises: a first reference picture storage unit configured to store a first reference picture corresponding to the original resolution of the first encoding target picture; and a second reference picture storage unit configured to store at least one second reference picture corresponding to the at least one pre-determined resolution. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the reconstructed image generation unit comprises: a down-sampling process unit configured to down-sample the first reference picture to the at least one pre-determined resolution, construct the at least one second reference picture down-sampled to the at least one pre-determined resolution, and provide the at least one second reference picture to the second reference picture storage unit; and an up-sampling process unit configured to up-sample the at least one second reference picture to the original resolution of the input image, construct the first reference picture up-sampled to the original resolution, and provide the first reference picture to the first reference picture storage unit. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the sampling unit is configured to output the encoding target picture by down-sampling the input image to a pre-determined resolution or image skip information indicating whether or not to skip the input image. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the encoding unit is configured to encode information indicating the encoding level of the input image. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the information indicating the encoding level of the input image is included in at least one field of a sequence parameter set, and a picture parameter set. ### Claim 11 An image decoding apparatus comprising: an entropy decoding unit configured to reconstruct encoded image data from a bitstream; an encoding level check unit configured to check an encoding level of the encoded image data; a decoding unit configured to decode the encoded data, construct a decoded picture based on the encoded data, and construct an output image corresponding to an input image of an image encoding apparatus in association with the decoded picture and the encoded level of the decoded picture; a reconstructed image generation unit configured to generate a first reconstructed image corresponding to the output image in association with the encoding level and at least one second reconstructed image corresponding to at least one pre-determined resolution, and a reference picture storage unit configured to store first reconstructed image and the at least one second reconstructed image, wherein the encoding level check unit checks whether or not input image is skipped and whether or not a spatial resolution of the input image is transformed. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the encoding level check unit comprises: a frame skip check unit configured to check whether or not the input image is skipped; and a resolution decision unit configured to check whether or not the spatial resolution of the input image is transformed. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein the reconstructed image generation unit is configured to generate the first reconstructed image corresponding to a skipped input image using at least one of an image obtained by duplicating a previous output image, and a reconstructed image reconstructed by considering a temporal relationship between at least two previous output images and a skipped input image. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the reconstructed image generation unit is configured to transform the resolution of the first reconstructed image to at least one pre-determined resolution and generate the at least one second reconstructed image corresponding to the at least one pre-determined resolution. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the decoding unit comprises: a first decoder configured to decode a first decoded picture corresponding to an original resolution of the input image; a second decoder configured to decode a second decoded picture that is encoded by being down-sampled to a pre-determined resolution; a first reference picture storage unit configured to store a first reference picture corresponding to the original resolution of the first decoded picture; and a second reference picture storage unit configured to store at least one second reference picture including the second decoded picture of the pre-determined resolution and the at least one second reconstructed image transformed to the at least one pre-determined resolution. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the reconstructed image generation unit includes: a down-sampling process unit configured to down-sample the first reference picture to the at least one pre-determined resolution, construct the at least one second reference picture down-sampled to the at least one pre-determined resolution, and provide the at least one second reference picture to the second reference picture storage unit; and an up-sampling process unit configured to up-sample the at least one second reference picture to the original resolution of the input image, construct the first reference picture up-sampled to the original resolution, and provide the first reference picture to the first reference picture storage unit. ### Claim 17 An image decoding method comprising: reconstructing encoded image data from a bitstream; checking an encoding level of the encoded image data; decoding the encoded data; constructing a decoded picture based on the encoded data; constructing an output image corresponding to an input image of an image encoding apparatus in association with the decoded picture and the encoded level of the decoded picture; generating a first reconstructed image corresponding to the output image and at least one second reconstructed image corresponding to at least one pre-determined resolution, and storing first reconstructed image and the at least one second reconstructed image, wherein checking an encoding level of the encoded image data comprises checking whether or not input image is skipped and checking whether or not a spatial resolution of the input image is transformed.