Surveying system with image-based measuring

US11566896B2 · kind B2 · utility

Assignee

• LEICA GEOSYSTEMS AG · CH

Inventors

• Bernhard Richter · Puchheim, DE
• Zoltán TÖRÖK · Berneck, CH
• Elmar Vincent Van Der Zwan · Altstätten, CH
• Bernhard Metzler · Dornbirn, AT

Key dates

• Filing date: Aug 22, 2019
• Grant date: Jan 31, 2023
• Expiry date: Feb 1, 2041

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S19/14
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for image-based point measurement includes moving a surveying system along a path through a surrounding and capturing a series of images of the surrounding. A subset of images are defined as frames and a subset of frames are defined as key-frames. Textures are identified in first and second frames and are tracked in successive frames to generate first and second frame feature lists. A structure from motion algorithm is used to calculate camera poses for the images based on the first and second frame feature lists. Corresponding image points in images of the series of images are identified using feature recognition in at least a plurality of images. Three-dimensional coordinates of the selected image point are determined using forward intersection with the poses of the subset of images in which corresponding image points are identified. The three-dimensional coordinates of the selected image point are presented to the user.