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:
Jul. 24, 2018
Filed:
Jun. 24, 2016
Evernote Corporation, Redwood City, CA (US);
Ilya Buryak, Moscow, RU;
Eugene Livshitz, San Mateo, CA (US);
Alexander Pashintsev, Cupertino, CA (US);
Boris Gorbatov, Sunnyvale, CA (US);
EVERNOTE CORPORATION, Redwood City, CA (US);
Abstract
Detecting an aspect ratio of an image captured with a smartphone includes detecting at least one convex quadrangle of arbitrary shape on the image and generating a plurality of additional convex quadrangles having vertices in a pre-determined vicinity of vertices of the quadrangle on the image. A linear projective mapping matrix is generated for mapping each of the quadrangle and the plurality of additional quadrangles onto a unit square. A plurality of estimated focal lengths of the camera of the smartphone is determined according to matrixes corresponding to the linear projective mappings onto a unit square of the quadrangle and each of the plurality of additional quadrangles. The quadrangle is used to determine the aspect ratio of the image in response to a range of the plurality of estimated focal lengths including a true value of the focal length of the camera of the smartphone.