Railroad track recognition device, program, and railroad track recognition method

A method for recognizing a railroad track comprising:

• calculating an index value, to be used for evaluating railroad-track-likeness, for each pixel or each pixel group of a captured image captured by a capturing device on a train vehicle;
• determining a first plurality of line segments between each of multiple points on a first end side of a first search area and each of multiple points on a second end side of the first search area, calculating an evaluation value for each of the first plurality of line segments from the index values of the pixels or the index values of the pixel groups, and selecting, based on the evaluation values, a line segment having a larger evaluation value than that of the other line segments;
• determining a second plurality of line segments between a reference point on an end of the line segment selected from the first plurality of line segments and each of multiple points on an end side of a second search area, calculating an evaluation value for each of the second plurality of line segments from the index values of the pixels or the index values of the pixel groups, and selecting, based on the evaluation values, a line segment having a larger index value than that of the other line segments included in the second search area;
• determining a third plurality of line segments between a reference point on an end of the line segment selected from the second plurality of line segments and each of multiple points on an end side of a third search area, calculating an evaluation value for each of the third plurality of line segments from the index values of the pixels or the index values of the pixel groups, and selecting, based on the evaluation values, a line segment having a larger evaluation value than that of the other line segments included in the third search area;
• and
• recognizing a railroad track based on the reference points of the selected line segments.