# US 9,438,929 B2 · Method and apparatus for encoding and decoding an image by using an adaptive search range decision for motion estimation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,929 B2 - Document ID: US9438929B2 - Status: Granted - Kind: B2 - Application number: 14/218,273 - Filed: 2014-03-18 - Published: 2014-09-18 - Granted: 2016-09-06 - Earliest claimed: 2013-03-18 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Hyung-ju Chun; Sung-oh Kim; Chan-sik Park; Kyo-hyuk Lee - Web page: https://patentgrep.com/patent/US9438929B2 ## CPC - H04N 19/57: Motion estimation characterised by a search window with variable size or shape - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An encoding and decoding method and apparatus are disclosed. whereby, According to the disclosed method, in response to a current frame including a current block being a P frame, a motion vector and an intra-mode-to-inter mode ratio of a frame encoded and decoded previously to the current frame are analyzed in order to determine a temporal search range and a spatial search range of a reference frame. ## Claims ### Claim 1 A method of encoding an adaptive search range decision in motion estimation, the encoding method comprising: determining intra-mode to inter-mode ratio based on motion information of a frame previous to a current frame including a current block; adjusting a spatial search range according to a motion vector of the reference frame in response to the intra-mode ratio exceeding a certain value; and performing motion estimation on the current block within the determined search range in order to generate a motion vector of the current block, wherein the adjusting the spatial search range includes: enlarging the spatial search range based on a difference between a size of a total sum of motion vectors along a first-axis of the reference frame and a size of a total sum of motion vectors along a second-axis of the reference frame. ### Claim 2 (depends on 1) The encoding method of claim 1, wherein, the current frame is a P frame, and the previous frame is encoded and decoded previously to the current frame. ### Claim 3 (depends on 1) The encoding method of claim 1, wherein the adjusting the spatial search range includes: enlarging the spatial search range in response to the intra-mode to inter-mode ratio being equal to or less than the certain value. ### Claim 4 (depends on 1) The encoding method of claim 1, wherein the adjusting of the spatial search range includes: enlarging a width ratio of the spatial search range in response to a size of a total sum of motion vectors along an x-axis of the previous frame being greater by a predetermined value or more than a size of a total sum of motion vectors along a y-axis of the previous frame; enlarging a length ratio of the spatial search range in response to the size of the total sum of motion vectors along the y-axis of the previous frame is greater by the predetermined value or more than the size of the total sum of motion vectors along the x-axis of the previous frame; and maintaining the spatial search range as a basic value in response to a condition for the enlarging of a width ratio or the enlarging of a length ratio is not satisfied. ### Claim 5 (depends on 1) The encoding method of claim 1, wherein the determining of a temporal search range includes adjusting the temporal search range according to the determining of the spatial search range. ### Claim 6 A method of decoding an adaptive search range decision in motion estimation, the decoding method comprising: detecting a motion vector of a current block from an encoded image; and generating, by using the motion vector, a predictive block included in a temporal search range and a spatial search range that are determined according to intra-mode to inter-mode ratio determined based on motion information of a frame previous to a current frame including a current block, wherein the determining of the spatial range includes: adjusting the spatial search range according to a motion vector of the reference frame in response to the intra-mode ratio exceeding a certain value and wherein the adjusting the spatial range includes: enlarging the spatial search range based on a difference between a size of a total sum of motion vectors along a first-axis of the reference frame and a size of a total sum of motion vectors along a second-axis of the reference frame. ### Claim 7 (depends on 6) The decoding method of claim 6, wherein, the current frame is a P frame, and the previous frame is encoded and decoded previously to the current frame. ### Claim 8 (depends on 6) The decoding method of claim 6, wherein the determining of the spatial search range includes: enlarging the spatial search range in response to the intra-mode to inter-mode ratio being equal to or less than the certain value. ### Claim 9 (depends on 8) The decoding method of claim 8, wherein the adjusting of the spatial search range includes: enlarging a width ratio of the spatial search range in response to a size of a total sum of motion vectors along an x-axis of the previous frame is greater by a predetermined value or more than a size of a total sum of motion vectors along an y-axis; enlarging a length ratio of the spatial search range in response to the size of the total sum of the motion vectors along the y-axis of the previous frame being greater by the predetermined value or more than the size of the total sum of the motion vectors along the x-axis; and maintaining the spatial search range as a basic value in response to a condition for the enlarging of a width ratio or the enlarging of a length ratio is not satisfied. ### Claim 10 (depends on 6) The decoding method of claim 6, wherein the determining of a temporal search range includes adjusting the temporal search range according to the determining of the spatial search range. ### Claim 11 An encoding apparatus for an adaptive search range decision in motion estimation, the encoding apparatus comprising: a motion information analyzer configured to determine intra-mode to inter-mode ratio based on motion information of a frame previous to a current frame which includes a current block; a search region controller configured to adjust a spatial search range according to a motion vector of the reference frame in response to the intra-mode ratio exceeding a certain value; and a predictor configured to perform motion estimation on the current block within the determined search range to generate a motion vector of the current block, wherein the adjusting the spatial search range includes: enlarging the spatial search range based on a difference between a size of a total sum of motion vectors along an first-axis of the reference frame and a size of a total sum of motion vectors along a second-axis of the reference frame. ### Claim 12 (depends on 11) The encoding apparatus of claim 11, wherein, the current frame is a P frame, and the previous frame is encoded and decoded previously to the current frame. ### Claim 13 (depends on 11) The encoding apparatus of claim 11, wherein, the search range controller is configured to search the spatial search range in response to the intra-mode to inter-mode ratio being equal to or less than the certain value. ### Claim 14 (depends on 11) The encoding apparatus of claim 11, wherein the adjusting of the spatial search range includes: enlarging a width ratio of the spatial search range in response to a size of a total sum of motion vectors along an x-axis of the previous frame being greater by a predetermined value or more than a size of a total sum of motion vectors along a y-axis of the previous frame; enlarging a length ratio of the spatial search range in response to the size of the total sum of motion vectors along the y-axis of the previous frame being greater by the predetermined value or more than the size of the total sum of motion vectors along the x-axis; and maintaining the spatial search range as a basic value in response to a condition for the enlarging of a width ratio or the enlarging of a length ratio not being satisfied. ### Claim 15 (depends on 11) The encoding apparatus of claim 11, wherein the determining of a temporal search range includes adjusting the temporal search range according to the determining of the spatial search range. ### Claim 16 A decoding apparatus for an adaptive search range decision in motion estimation, the decoding apparatus comprising: a motion information detector configured to detect a motion vector of a current block from an encoded image; and a predictive block generator configured to generate, by using the motion vector, a predictive block included in a temporal search range and a spatial search range that are determined according to intra-mode to inter-mode ratio determined based on motion information of a frame previous to a current frame including a current block, wherein the determining of the spatial range includes: adjusting the spatial search range according to a motion vector of the reference frame in response to the intra-mode ratio exceeding a certain value and wherein the adjusting the spatial range includes: enlarging the spatial search range based on a difference between a size of a total sum of motion vectors along a first-axis of the reference frame and a size of a total sum of motion vectors along a second-axis of the reference frame. ### Claim 17 (depends on 16) The decoding apparatus of claim 16, wherein, the current frame is a P frame, and the previous frame is encoded and decoded previously to the current frame. ### Claim 18 (depends on 16) The decoding apparatus of claim 16, wherein the determining of the spatial search range includes: enlarging the spatial search range in response to the intra-mode to inter-mode ratio being equal to or less than the certain value. ### Claim 19 (depends on 18) The decoding apparatus of claim 18, wherein the adjusting of the spatial search range includes: enlarging a width ratio of the spatial search range in response to a size of a total sum of motion vectors along an x-axis of the previous frame being greater by a predetermined value or more than a size of a total sum of motion vectors along a y-axis of the previous frame; enlarging a length ratio of the spatial search range in response to the size of the total sum of motion vectors along the y-axis of the previous frame being greater by the predetermined value or more than the size of the total sum of motion vectors along the x-axis of the previous frame; and maintaining the spatial search range as a basic value in response to a condition for the enlarging of a width ratio or the enlarging of a length ratio not being satisfied. ### Claim 20 (depends on 16) The decoding apparatus of claim 16, wherein the determining of a temporal search range includes adjusting the temporal search range according to the determining of the spatial search range.