# US 7,898,902 B2 · Method of representation of sonar images > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,898,902 B2 - Document ID: US7898902B2 - Status: Granted - Kind: B2 - Application number: 12/138,702 - Filed: 2008-06-13 - Published: 2009-12-17 - Granted: 2011-03-01 - Earliest claimed: 2008-06-13 - Assignees: Codaoctopus Group - Inventors: Martyn Sloss - Web page: https://patentgrep.com/patent/US7898902B2 ## CPC - G03B 42/06: using ultrasonic, sonic or infrasonic waves - G01S 7/6245: {Stereoscopic displays; Three-dimensional displays; Pseudo-three dimensional displays} - G01S 15/89: for mapping or imaging - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract Sonar three dimensional data are represented by a two dimensional image. Pixels of the two dimensional image are emphasized if the if the three dimensional data associated with the pixel differ by more than a criterion from the three dimensional data associated with neighboring pixels. ## Claims ### Claim 1 A method of presenting sonar imaging data, comprising: a) receiving three dimensional sonar imaging data; then b) constructing a two dimensional image from the three dimensional imaging data, the two dimensional image comprising pixels arranged as an array, wherein each pixel conveys information; c) associating a particular change in the three dimensional imaging data with a particular pixel in the two dimensional image; then d) if a particular change in the three dimensional sonar imaging data is greater than a criterion, emphasizing the associated particular pixel in the two dimensional image. ### Claim 2 (depends on 1) The method of claim 1, wherein range data are presented as an image function of two polar angles, and wherein the particular change is a difference between the range coordinate of the particular pixel and the range coordinate of a pixel neighboring the particular pixel. ### Claim 3 (depends on 2) The method of claim 2, wherein for each pixel a range difference between that pixel and each of the four nearest neighboring pixels is calculated, and if any of the four range differences are greater than a criterion, that pixel is emphasized. ### Claim 4 (depends on 2) The method of claim 2, wherein for each pixel the range difference between that pixel and each of the two neighboring pixels in a direction of one of the two polar coordinates is calculated, and if either of the two range differences are greater than a criterion, that pixel is emphasized. ### Claim 5 (depends on 1) The method of claim 1, wherein for each pixel a plane is fit to the three dimensional coordinates of each pixel in the image, and wherein the normal to the plane is calculated, and wherein the pixel is emphasized if the normal to the plane satisfies a criterion. ### Claim 6 (depends on 1) The method of claim 1, wherein the particular changes are changes in a depth coordinate in a Cartesian three dimensional image. ### Claim 7 (depends on 1) The method of claim 1, wherein the particular changes are changes in a horizontal coordinate in a Cartesian three dimensional image. ### Claim 8 (depends on 1) The method of claim 1, wherein the three dimensional sonar imaging data is taken in a single ping. ### Claim 9 (depends on 1) The method of claim 1, wherein the three dimensional sonar imaging data are taken in a plurality of pings. ### Claim 10 A method of presenting sonar imaging data, comprising: a) receiving three dimensional sonar imaging data; then b) constructing a two dimensional image from the three dimensional imaging data, the two dimensional image comprising pixels arranged as an array, wherein each pixel conveys information, wherein the two dimensional image comprises an image in a Cartesian coordinate system having a first and a second horizontal axis and a vertical axis, c) associating a particular change in the three dimensional imaging data with a particular pixel in the two dimensional image; then d) if a particular change in the three dimensional sonar imaging data is greater than a criterion, emphasizing the associated particular pixels in the two dimensional image. ### Claim 11 (depends on 10) The method of claim 10, wherein the particular changes are changes in the first horizontal coordinate, and wherein the first horizontal coordinate data are presented as an image function of the second horizontal coordinate and the vertical coordinate. ### Claim 12 (depends on 11) The method of claim 11, wherein for each pixel a difference in the first horizontal coordinate between that pixel and each of the four neighboring pixels is calculated, and if any of the four differences are greater than a criterion, that pixel is emphasized. ### Claim 13 (depends on 11) The method of claim 11, wherein for each pixel a difference in the first horizontal coordinate between that pixel and each of the two neighboring pixels in a direction of either the second coordinate axis or the vertical coordinate axis is calculated, and if either of the two range differences are greater than a criterion, that pixel is emphasized. ### Claim 14 (depends on 11) The method of claim 11, wherein for each pixel a plane is fit to the coordinates of each pixel and its surrounding pixels in the image, and wherein the normal to the plane is calculated, and wherein the pixel is emphasized if the normal to the plane satisfies a criterion. ### Claim 15 (depends on 10) The method of claim 10, wherein the particular changes are changes in the vertical coordinate, and wherein the vertical coordinate data are presented as an image function of the first and second horizontal coordinates. ### Claim 16 (depends on 10) The method of claim 10, wherein the three dimensional sonar imaging data is taken in a single ping. ### Claim 17 (depends on 10) The method of claim 10, wherein the three dimensional sonar imaging data are taken in a plurality of pings. ### Claim 18 A method of presenting sonar imaging data, comprising: a) projecting a sound wave into a sound wave transmitting medium; b)receiving sound waves reflected from one or more objects in the sound wave transmitting medium, each of the one or more objects having a defined three dimensional location in the in the sound wave transmitting medium; c) transforming the reflected sound waves into electrical signals, the electrical signals comprising the sonar imaging data; d) analyzing the electrical signals to record at least the three dimensional locations of the one or more objects, wherein in the electrical signals are analyzed by a processor e) constructing a two dimensional image from the three dimensional imaging data, the two dimensional image comprising pixels arranged as an array, wherein each pixel conveys information; f) associating a particular change in the three dimensional imaging data with a particular pixel in the two dimensional image; then g) if a particular change in the three dimensional sonar imaging data is greater than a criterion, emphasizing the associated particular pixel in the two dimensional image. ### Claim 19 (depends on 18) The method of claim 18, wherein the two dimensional image is displayed on a display device.