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.

Date of Patent:
Oct. 06, 2020

Filed:

Aug. 09, 2018
Applicants:

Massachusetts Institute of Technology, Cambridge, MA (US);

Georgia Tech Research Corporation, Atlanta, GA (US);

Inventors:

Barmak Heshmat Dehkordi, San Mateo, CA (US);

Albert Redo-Sanchez, Zizur Mayor, ES;

Ramesh Raskar, Cambridge, MA (US);

Alireza Aghasi, Chamblee, GA (US);

Justin Romberg, Decatur, GA (US);

Assignees:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06K 9/46 (2006.01); G06K 9/00 (2006.01); G06K 9/20 (2006.01); G06K 9/52 (2006.01);
U.S. Cl.
CPC ...
G06K 9/4642 (2013.01); G06K 9/00543 (2013.01); G06K 9/2018 (2013.01); G06K 9/522 (2013.01); G06K 2209/01 (2013.01);
Abstract

A sensor may measure light reflecting from a multi-layered object at different times. A digital time-domain signal may encode the measurements. Peaks in the signal may be identified. Each identified peak may correspond to a layer in the object. For each identified peak, a short time window may be selected, such that the time window includes a time at which the identified peak occurs. A discrete Fourier transform of that window of the signal may be computed. A frequency frame may be computed for each frequency in a set of frequencies in the transform. Kurtosis for each frequency frame may be computed. A set of high kurtosis frequency frames may be averaged, on a pixel-by-pixel basis, to produce a frequency image. Text characters that are printed on a layer of the object may be recognized in the frequency image, even though the layer is occluded.


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