The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 2021
Filed:
Jan. 25, 2019
Wenzhou Medical University, Wenzhou, CN;
WENZHOU MEDICAL UNIVERSITY, Wenzhou, CN;
Abstract
The invention provides a calibration method and a calibration device of a system for measuring corneal parameters, and particularly the invention provides a system calibration method and device for geometric distortion, caused by camera shooting angle when measuring cornea-related parameters, of a digital slit lamp and a system of similar principles based on machine vision. The method of the invention comprises the steps of: placing a calibration block on a calibration stand, using a slit lamp to shine light perpendicularly to the calibration block, and then photographing in a manner that four vertexes of a cross section are all within a visual range of a digital camera, so as to obtain the four corners and thus corresponding four edges of the cross section; restoring the position of a real image in the image using a ray tracing method; and then performing geometric distortion correction according to real-image coordinates of the four corners in the image and corresponding real-space lengths thereof, thus geometric distortion caused by the camera shooting angle can be eliminated, and the real dimension represented by each pixel can be obtained.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile