US 12,277,728 B2
Pupil detection device, line-of-sight detection device, occupant monitoring system, and pupil detection method
Atsushi Matsumoto, Tokyo (JP); Ryosuke Torama, Tokyo (JP); Shintaro Watanabe, Tokyo (JP); and Ryohei Murachi, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/790,678
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Jan. 8, 2020, PCT No. PCT/JP2020/000213
§ 371(c)(1), (2) Date Jul. 1, 2022,
PCT Pub. No. WO2021/140579, PCT Pub. Date Jul. 15, 2021.
Prior Publication US 2023/0043992 A1, Feb. 9, 2023
Int. Cl. G06T 7/73 (2017.01); A61B 3/113 (2006.01); A61B 5/18 (2006.01); G06V 10/60 (2022.01); G06V 20/59 (2022.01); G06V 40/18 (2022.01); G06V 40/19 (2022.01)
CPC G06T 7/74 (2017.01) [G06V 10/60 (2022.01); G06V 20/597 (2022.01); G06V 40/19 (2022.01); G06V 40/193 (2022.01); G06T 2207/30201 (2013.01); G06T 2207/30244 (2013.01); G06T 2207/30268 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A pupil detection device comprising:
processing circuitry
to obtain image data representing an eye area image in an image captured by a camera, the eye area image including a plurality of image units arranged in an X-direction and a Y-direction orthogonal to each other, each of the image units including one or more pixels adjacent to each other;
to calculate luminance gradient vectors corresponding to the respective individual image units in the eye area image, using a difference value between luminance values of two image units in the X-direction and a difference value between luminance values of two image units in the Y-direction;
to calculate evaluation values corresponding to the respective individual image units, using a luminance gradient angle corresponding to the direction of each of the luminance gradient vectors; and
to detect a pupil location in the eye area image, using the evaluation values.