Detection device, method and program thereof

[0253]First, the rotation angle detecting portion 165 will be described with reference to FIGS. 28 and 29.

[0254]FIG. 28 is a block diagram showing a functional construction of a second embodiment of the rotation angle detecting portion 165. The rotation angle detecting portion 165 shown in FIG. 28 detects the rotation angle of the camera 112 by the combined use of the least-squares method and the RANSAC, one of the robust estimation techniques. The rotation angle detecting portion 165 shown in FIG. 28 is configured to include a rotation angle calculating portion 241, an error calculating portion 242, a selecting portion 421, and a rotation angle estimating portion 422. In the drawing, portions corresponding to those of FIG. 5 will be denoted by the same reference numerals, and repeated descriptions will be omitted for the processes that are identical to those of FIG. 5.

[0255]Like the selecting portion 243 of FIG. 5, the selecting portion 421 selects one of the temporary rotation angles

[0262]Next, the rotation angle detecting portion 165 will be described with reference to FIGS. 30 and 31.

[0263]FIG. 30 is a block diagram showing a functional construction of a third embodiment of the rotation angle detecting portion 165. The rotation angle detecting portion 165 shown in FIG. 30 detects the rotation angle of the camera 112 by the use of the Hough transform, one of the robust estimation techniques. The rotation angle detecting portion 165 shown in FIG. 30 is configured to include a Hough transform portion 441 and an extracting portion 442.

[0264]The Hough transform portion 441 acquires information representing the detected motion vector from the vector detecting portion 164. As will be described with reference to FIG. 31, the Hough transform portion 441 performs a Hough transform on the above-described expression (11) for the motion vector detected by the vector detecting portion 164 and supplies information representing the results of the Hough transform to the extracti