发明名称 |
EXTRACTING FEATURE QUANTITIES FROM AN IMAGE TO PERFORM LOCATION ESTIMATION |
摘要 |
A feature extraction method for extracting a feature from an image includes receiving an image and measured acceleration data from a mobile device; obtaining a gravity vector in the image in a camera coordinate system based on the measured acceleration data; obtaining a vanishing point in the image in a vertical direction in a screen coordinate system using the gravity vector; obtaining differential vectors along two axes for each pixel in the screen coordinate system; obtaining a connection line vector connecting each of the pixels with the vanishing point; identifying a vertical edge based on determining that an angle formed by the differential vector and the connection line vector is within a certain threshold range; obtaining the sum of strengths of vertical edges and writing the sum in a predetermined variable array; extracting a keypoint based on the variable array; and calculating a feature quantity from the keypoint. |
申请公布号 |
US2014050353(A1) |
申请公布日期 |
2014.02.20 |
申请号 |
US201313965439 |
申请日期 |
2013.08.13 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
TAKAHASHI TOSHIHIRO |
分类号 |
G06K9/46 |
主分类号 |
G06K9/46 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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