公开(公告)号：US10796190B2

公开(公告)日：2020-10-06

申请号：US16059144

申请日：2018-08-09

申请人： Massachusetts Institute of Technology ,  Georgia Tech Research Corporation

发明人： Barmak Heshmat Dehkordi ,  Albert Redo-Sanchez ,  Ramesh Raskar ,  Alireza Aghasi ,  Justin Romberg

IPC分类号： G06K9/46 ,  G06K9/00 ,  G06K9/20 ,  G06K9/52

摘要： 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.

公开(公告)号：US20190050669A1

公开(公告)日：2019-02-14

申请号：US16059144

申请日：2018-08-09

申请人： Massachusetts Institute of Technology ,  Georgia Tech Research Corporation

发明人： Barmak Heshmat Dehkordi ,  Albert Redo-Sanchez ,  Ramesh Raskar ,  Alireza Aghasi ,  Justin Romberg

IPC分类号： G06K9/46 ,  G06K9/20 ,  G06K9/00

CPC分类号： G06K9/4642 ,  G06K9/00543 ,  G06K9/2018 ,  G06K9/522 ,  G06K2209/01

摘要： 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.