Signal light display determination device, signal light display determination method, and non-transitory computer-readable recording medium

1. A signal light display determination device comprising:

a memory to store a program; and

a processor to execute the program,

wherein

the processor that executes the program to

acquire, for each of a plurality of frames, lightness of a first region and a second region that is in close proximity to the first region, the first region and the second region being within a region in the plurality of frames and containing at least a portion of a display of a signal light that is image-captured consecutively by a camera,

correct, based on the acquired lightness of the second region, rate of change in the acquired lightness of the first region in a case in which a determination based on rate of change in the acquired lightness of the second region is made that a display state of the display included in the second region has changed from a lit state to an unlit state, from the unlit state to the lit state, or maintains the lit state continuously in a predetermined number of frames, and

determine, based on the corrected rate of the change in the lightness of the first region, a display state of the display included in the first region.

2. The signal light display determination device according to claim 1 , wherein the processor acquires lightness of a region of a first lamp portion and a region of a second lamp portion of the signal light image-captured by the camera as the first region and the second region.

3. The signal light display determination device according to claim 1 , wherein the processor acquires lightness of a lit lamp region and a non-lit lamp region of the signal light image-captured by the camera as the first region and the second region.

4. The signal light display determination device according to claim 1 , wherein the processor acquires lightness of the first region and the second region each time the signal light is image-captured the camera.

5. A signal light display determination method comprising:

acquiring, for each of a plurality of frames by a processor of a computer, lightness of a first region and a second region that is in close proximity to the first region, the first region and the second region being within a region in the plurality of frames and containing at least a portion of a display of a signal light that is image-captured consecutively by a camera;

correcting, based on the acquired lightness of the second region by the processor of the computer, rate of change the acquired lightness of the first region in a case in which a determination based on rate of change in the acquired lightness of the second region is made that a display state of the display included in the second region has changed from a lit state to an unlit state, from the unlit state to the lit state, or maintains the lit state continuously in a predetermined number of frames; and

determining, based on the corrected rate of the change in the lightness of the first region by the processor of the computer, a display state of the display included in the first region.

6. A non-transitory computer-readable recording medium having recording therein a program that causes a processor of a computer to:

Acquire, for each of a plurality of frames, lightness of a first region and a second region that is in close proximity to the first region, the first region and the second region being within a region in the plurality of frames and containing at least a portion of a display of a signal light that is image-captured consecutively by a camera,

correct, based on the acquired lightness of the second region, rate of change in the acquired lightness of the first region in a case in which a determination based on rate of change in the acquired lightness of the second region is made that a display state of the display included in the second region has changed from a lit state to an unlit state, from the unlit state to the lit state, or maintains the lit state continuously in a predetermined number of frames, and

determine, based on the corrected rate of the change in the lightness of the first region, a display state of the display included in the first region.

7. The signal light display determination device according to claim 1 , wherein the second region is adjacent to both ends of the first region.

8. The signal light display determination device according to claim 1 ,

wherein

the processor

calculates average values of the lightness of the first region and the second region for each frame,

calculates movement average lightness of the first region and the second region in the predetermined number of frames using the calculated average values of lightness,

calculates rate of change in the lightness of the first region based on the calculated movement average lightness of the first region and the average value of the lightness of the first region in the latest frame among the plurality of flames, and

calculates rate of change in the lightness of the second region based on the calculated movement average lightness of the second region and average value of the lightness of the second region in the latest frame among the plurality of frames.

9. The signal light display determination method according to claim 5 , wherein, in the acquiring of the lightness, the processor acquires lightness of a region of a first lamp portion and a region of a second lamp portion of the signal light image-captured by the camera as the first region and the second region.

10. The signal light display determination method according to claim 5 , wherein, in the acquiring of the lightness, the processor acquires lightness of a lit lamp region and a non-lit lamp region of the signal light image-captured by the camera as the first region and the second region.

11. The signal light display determination method according to claim 5 , wherein, in the acquiring of the lightness, the processor acquires lightness of the first region and the second region each time the signal light is image-captured the camera.

12. The signal light display determination method according to claim 5 , wherein the second region is adjacent to both ends of the first region.

13. The signal light display determination method according to claim 5 ,

wherein,

the correcting includes

calculating, by the processor of the computer, average values of the lightness of the first region and the second region for each frame,

calculating, by the processor of the computer, movement average lightness of the first region and the second region in the predetermined number of frames using the calculated average values of lightness,

calculating, by the processor of the computer, rate of change in the lightness of the first region based on the calculated movement average lightness of the first region and the average value of the lightness of the first region in the latest frame among the plurality of flames, and

calculating, by the processor of the computer, rate of change in the lightness of the second region based on the calculated movement average lightness of the second region and average value of the lightness of the second region in the latest frame among the plurality of frames.

14. The non-transitory computer-readable recording medium according to claim 6 further having recorded therein a program that causes the processor of the computer to acquire lightness of a region of a first lamp portion and a region of a second lamp portion of the signal light image-captured by the camera as the first region and the second region.

15. The non-transitory computer-readable recording medium according to claim 6 further having recorded therein a program that causes the processor of the computer to acquire lightness of a lit lamp region and a non-lit lamp region of the signal light image-captured by the camera as the first region and the second region.

16. The non-transitory computer-readable recording medium according to claim 6 further having recorded therein a program that causes the processor of the computer to acquire lightness of the first region and the second region each time the signal light is image-captured the camera.

17. The non-transitory computer-readable recording medium according to claim 6 , wherein the second region is adjacent to both ends of the first region.

18. The non-transitory computer-readable recording medium according to claim 6 further having recorded therein a program that causes the processor of the computer to:

calculate average values of the lightness of the first region and the second region for each frame,

calculate movement average lightness of the first region and the second region in the predetermined number of frames using the calculated average values of lightness,

calculate rate of change in the lightness of the first region based on the calculated movement average lightness of the first region and the average value of the lightness of the first region in the latest frame among the plurality of flames, and

calculate rate of change in the lightness of the second region based on the calculated movement average lightness of the second region and average value of the lightness of the second region in the latest frame among the plurality of frames.