# US 2010/0165101 A1 · Feature detection apparatus and method for measuring object distances > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0165101 A1 - Document ID: US20100165101A1 - Status: Published application - Kind: A1 - Application number: 12/648,097 - Filed: 2009-12-28 - Published: 2010-07-01 - Earliest claimed: 2007-07-02 - Assignees: Trimble Jena GmbH - Inventors: Torsten Kludas; Nick Mein; Brendon Swann - Web page: https://patentgrep.com/patent/US20100165101A1 ## CPC - G01C 3/04: Adaptation of rangefinders for combination with telescopes or binoculars - G06V 10/987: {with the intervention of an operator} - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A feature detection apparatus and method for obtaining in a defined area of interest a parametric shape based on a selected combination of parameter values, constituting an approximation to an object feature. The feature detection apparatus includes an input unit for receiving at least two area indicator lines for defining in a digital image an area of interest, a parameter range defining unit for defining ranges of at least two parameters of a parametric shape, for which the parametric shape intersects at least one of the area indicator lines; a parameter selection unit for selecting a combination of parameter values from the parameter ranges, for which the parametric shape constitutes an approximation to an object feature of the object in the area of interest; and an output unit for providing the parametric shape based on said combination of parameter values for a display in the digital image. ## Claims ### Claim 1 A feature detection apparatus comprising: an input unit for receiving at least two area indicator lines for defining in a digital image an area of interest comprising parts of an object; a parameter range defining unit for defining ranges of at least two parameters of a parametric shape to be introduced into the digital image, for which the parametric shape intersects at least one of the area indicator lines; a parameter selection unit for selecting a combination of parameter values from the parameter ranges, for which the parametric shape constitutes an approximation to an object feature of the object in the area of interest; and an output unit for providing the parametric shape based on said combination of parameter values for display in the digital image. ### Claim 2 (depends on 1) The feature detection apparatus of claim 1 wherein the input unit is adapted to receive information identifying the parametric shape, the parametric shape constituting one of a plurality of pre-selectable candidate parametric shapes. ### Claim 3 (depends on 1) The feature detection apparatus of claim 1 wherein the parameter range defining unit is adapted to define ranges of parameters of a plurality of different parametric shapes, for which each of the parametric shapes intersects at least one of the area indicator lines. ### Claim 4 (depends on 1) The feature detection apparatus of claim 1 wherein the parameter selection unit is adapted to select the combination of parameter values such that the parametric shape constitutes a best fit approximation to the object feature of the object in the area of interest. ### Claim 5 (depends on 1) The feature detection apparatus of claim 1 wherein the parameter range defining unit is adapted to define sub ranges of the at least two parameters of at least one parametric shape, for which the at least one parametric shape intersects at least two area indicator lines. ### Claim 6 (depends on 1) The feature detection apparatus of claim 1 wherein the input unit is adapted to receive at least two indicator points to define the end points of an area indicator line. ### Claim 7 (depends on 1) The feature detection apparatus of claim 1 wherein the at least two area indicator lines are based on two indicator points, the area indicator lines extending through the indicator points so that the area indicator lines define an essentially rectangular area of interest. ### Claim 8 (depends on 1) The feature detection apparatus of claim 1 further comprising a detection unit for obtaining object feature pixels of the object feature in the area of interest by processing the area of interest using a detection algorithm or by an operator for selecting the object feature pixels in the area of interest. ### Claim 9 (depends on 8) The feature detection apparatus of claim 8 further comprising a calculation unit, for calculating the approximation to said object feature based on the obtained object feature pixels of the object feature. ### Claim 10 (depends on 8) The feature detection apparatus of claim 8 further comprising: a filter unit for filtering out from said obtained object feature pixels object feature pixels exceeding a specific distance to said parametric shape; and a recalculation unit for recalculating the approximation to said object feature based on the obtained object feature pixels not including the object feature pixels exceeding the specific distance. ### Claim 11 (depends on 1) The feature detection apparatus of claim 1 wherein the parametric shape based on said selected parameter values is superimposed on the object feature in the digital image on a display unit. ### Claim 12 (depends on 1) The feature detection apparatus of claim 1 wherein the parameter selection unit is adapted to select another combination of parameter values from the parameter ranges, for which a second parametric shape constitutes an approximation to a second object feature in the area of interest, and wherein a central line between the two parametric shapes is calculated. ### Claim 13 (depends on 1) An optical instrument comprising the feature detection apparatus according to claim 1. ### Claim 14 (depends on 13) The optical instrument according to claim 13 further comprising a first control element for defining on the parametric shape a measurement pixel and converting the measurement pixel into an approximation of coordinates of a position of the object to be measured assuming a default distance between the position and the optical instrument. ### Claim 15 (depends on 14) The optical instrument according to claim 14 further comprising: a lens arrangement for sighting the object; a positioning unit for adjusting the optical axis of the lens arrangement relative to at least one reference axis; and a second control element adapted to instruct the positioning unit to adjust the optical axis of the lens arrangement onto the position to be measured. ### Claim 16 (depends on 15) The optical instrument according to claim 15 further comprising: a distance measuring unit for measuring a distance to the object along a measurement axis of the distance measuring unit parallel to the optical axis of the lens arrangement, wherein the second control element is adapted to instruct the distance measuring unit to measure the distance to the position to be measured, and the first control element is further adapted to recalculate the coordinates of the position based on the measured distance. ### Claim 17 (depends on 15) The optical instrument according to claim 15 further comprising a camera aligned with the optical axis of the lens arrangement for acquiring the image of the area of interest comprising parts of the object. ### Claim 18 A method of feature detection, the method comprising: receiving at least two area indicator lines for defining in a digital image an area of interest comprising parts of an object; defining ranges of at least two parameters of a parametric shape to be introduced into the digital image, for which the parametric shape intersects at least one of the area indicator lines; selecting a combination of parameter values from the parameter ranges, for which the parametric shape constitutes an approximation to an object feature of the object in the area of interest; and providing the parametric shape based on said combination of parameter values for display in the digital image. ### Claim 19 (depends on 18) The method of claim 18 further comprising receiving information identifying the parametric shape, the parametric shape constituting one of a plurality of pre-selectable candidate parametric shapes. ### Claim 20 (depends on 18) The method of claim 18 further comprising defining ranges of parameters of a plurality of different parametric shapes, for which each of the parametric shapes intersects at least one of the area indicator lines. ### Claim 21 (depends on 18) The method of claim 18 further comprising selecting the combination of parameter values such that the parametric shape constitutes a best fit approximation to the object feature of the object in the area of interest. ### Claim 22 (depends on 18) The method of claim 18 further comprising defining sub ranges of the at least two parameters of at least one parametric shape, for which the at least one parametric shape intersects at least two area indicator lines. ### Claim 23 (depends on 18) The method of claim 18 further comprising receiving at least two indicator points to define the end points of an area indicator line. ### Claim 24 (depends on 18) The method of claim 18 wherein the at least two area indicator lines are based on two indicator points, the area indicator lines extending through the indicator points so that the area indicator lines define an essentially rectangular area of interest. ### Claim 25 (depends on 18) The method of claim 18 further comprising obtaining object feature pixels of the object feature in the area of interest by processing the area of interest using a detection algorithm or by an operator for selecting the object feature pixels in the area of interest. ### Claim 26 (depends on 25) The method of claim 25 further comprising calculating the approximation to said object feature based on the obtained object feature pixels of the object feature. ### Claim 27 (depends on 25) The method of claim 25 further comprising: filtering out from said obtained object feature pixels object feature pixels exceeding a specific distance to said parametric shape; and recalculating the approximation to said object feature based on the obtained object feature pixels not including the object feature pixels exceeding the specific distance. ### Claim 28 (depends on 18) The method of claim 18 wherein the parametric shape based on said selected parameter values is superimposed on the object feature in the digital image on a display unit. ### Claim 29 (depends on 18) The method of claim 18 further comprising: selecting another combination of parameter values from the parameter ranges, for which a second parametric shape constitutes an approximation to a second object feature in the area of interest; and calculating a central line between the two parametric shapes. ### Claim 30 (depends on 18) The method of claim 18 further comprising defining on the parametric shape a measurement pixel; and converting the measurement pixel into an approximation of coordinates of a position of the object to be measured assuming a default distance to the position. ### Claim 31 (depends on 30) The method of claim 30, further comprising: sighting the object with a lens arrangement; and adjusting the optical axis of the lens arrangement onto the position to be measured. ### Claim 32 (depends on 31) The method of claim 31 further comprising: measuring a distance to the position to be measured along a measurement axis; and recalculating the coordinates of the position based on the measured distance. ### Claim 33 (depends on 30) The method of claim 30 further comprising acquiring the image of the area of interest comprising parts of the object. ### Claim 34 (depends on 18) A program including instructions adapted to cause data processing means to carry out the method of claim 18. ### Claim 35 (depends on 18) A computer readable medium, in which a program is embodied, where the program, when executed, makes a computer execute the method of claim 18. ### Claim 36 (depends on 35) A computer program product comprising the computer readable medium according to claim 35.