Focal length validation using three-dimensional pose estimates

Abstract

A computer-implemented method includes receiving, by a computing system, a first image of an optical target from a camera. The first image is associated with a first position of the camera. The method also includes receiving, by the computing system, a second image of the optical target, Wherein the second image is associated with a second position of the camera. The method also includes determining an estimated displacement between the first position of the camera and the second position of the camera based on the first image and the second image. The method further includes determining a focal length based on the estimated displacement and a measured displacement of the camera between the first position and the second position.

What is claimed: 
     
         1 . A computer-implemented method comprising:
 receiving, by a computing system, a first image of an optical target from a camera, wherein the first image is associated with a first position of the camera;   receiving, by the computing system, a second image of the optical target, wherein the second image is associated with a second position of the camera;   determining an estimated displacement between the first position of the camera and the second position of the camera based on the first image and the second image; and   determining a focal length based on the estimated displacement and a measured displacement of the camera between the first position and the second position.   
     
     
         2 . The computer-implemented method of  claim 1 , further comprising:
 receiving, by the computing system, image data for the optical target from the camera; and   determining a distortion parameter associated with the camera, based on the image data,   wherein distortion corrections are performed on the first image and the second image based on the distortion parameter.   
     
     
         3 . The computer-implemented method of  claim 1 , wherein the focal length is based on a ratio of the estimated displacement and the measured displacement. 
     
     
         4 . The computer-implemented method of  claim 1 , wherein the measured displacement is determined using an optical ranging device. 
     
     
         5 . The computer-implemented method of  claim 3 , wherein the optical ranging device is a Light Detection and Ranging (LiDAR) sensor. 
     
     
         6 . The computer-implemented method of  claim 1 , wherein the first target comprises a checkerboard. 
     
     
         7 . The computer-implemented method of  claim 1 , further comprising:
 receiving, by the computing system, a third image of the optical target, wherein the third image is associated with a third position of the camera; and   determining an estimated displacement between the first position of the camera and the third position of the camera based on the first image and the second image.   
     
     
         8 . A system comprising:
 a storage device configured to store instructions;   a processor configured to execute the instructions and cause the processor to:
 receive a first image of an optical target from a camera, wherein the first image is associated with a first position of the camera, 
 receive a second image of the optical target wherein the second image is associated with a second position of the camera, 
 determine an estimated displacement between the first position of the camera and the second position of the camera based on the first image and the second image, and 
 determine a focal length based on the estimated displacement and a measured displacement of the camera between the first position and the second position. 
   
     
     
         9 . The system of  claim 8 , wherein the processor is configured to execute the instructions and cause the processor to:
 receive image data for the optical target from the camera; and   determine a distortion parameter associated with the camera, based on the image data,   wherein distortion corrections are performed on the first image and the second image based on the distortion parameter.   
     
     
         10 . The system of  claim 8 , wherein the focal length is based on a ratio of the estimated displacement and the measured displacement. 
     
     
         11 . The system of  claim 8 , wherein the measured displacement is determined using an optical ranging device. 
     
     
         12 . The system of  claim 10 , wherein the optical ranging device is a Leica. scanner or LiDAR sensor. 
     
     
         13 . The system of  claim 8 , wherein the first target comprises a checkerboard. 
     
     
         14 . The system of  claim 8 , wherein the processor is configured to execute the instructions and cause the processor to:
 receive a third image of the optical target, wherein the third image is associated with a third position of the camera; and   determine an estimated displacement between the first position of the camera and the third position of the camera based on the first image and the second image   
     
     
         15 . A non-transitory computer readable medium comprising instructions, the instructions, when executed by a computing system, cause the computing system to:
 receive a first image of an optical target from a camera, wherein the first image is associated with a first position of the camera;   receive a second image of the optical target, wherein the second image is associated with a second position of the camera;   determine an estimated displacement between the first position of the camera and the second position of the camera based on the first image and the second image; and   determine a focal length based on the estimated displacement and a measured displacement of the camera between the first position and the second position.   
     
     
         16 . The computer readable medium of  claim 15 , wherein the computer readable-medium further comprises the instructions that, when executed by the computing system, cause the computing system to:
 receive image data for the optical target from the camera; and   determine a distortion parameter associated with the camera, based on the image data,   wherein distortion corrections are performed on the first image and the second image based on the distortion parameter.   
     
     
         17 . The computer readable medium of  claim 15 , wherein the focal length is based on a ratio of the estimated displacement and the measured displacement. 
     
     
         18 . The computer readable medium of  claim 15 , wherein the measured displacement is determined using an optical ranging device. 
     
     
         19 . The computer readable medium of  claim 17 , wherein the optical ranging device is a Leica scanner or LiDAR sensor. 
     
     
         20 . The computer readable medium of  claim 15 , wherein the first target comprises a checkerboard.