| 摘要 |
The objective of the present invention is to provide a technique for obtaining an SfM rapidly and robustly. A computer system performing the role of a server receives, from a smartphone by way of a communication function, an image and a measurement result of an acceleration sensor. The computer system initially extracts only edges in a vertical direction from the image. To this end, the acceleration sensor is used to obtain a gravity vector in a camera coordinate system. Then, next, the system, using the gravity vector, obtains a vanishing point (u', v') for the vertical direction in a screen coordinate system. Next, the computer system, for each pixel (u, v) in the screen coordinate system, calculates a differential vector for brightness for the U and V directions. Next, the computer system, with respect to a collection of edges aligned in the vertical direction, obtains the sum of edge strengths in the vertical direction, and thereby extracts a line in the vertical direction. The computer system calculates a feature vector using the perimeter of the extracted line. |
