Method of detecting visual stress and photosensitive epilepsy triggers in video and mitigation device

1. A method for detecting visual stress scenes in a video, the method comprising:

receiving a video including scenes that may cause visual stress in some viewers;

generating a signal representing human perceptual response from scenes in the video, including:

passing the video through a spatiotemporal filter, and

generating a perceptual contrast portion of the perceptual response signal based on a function of a center area, a surround area, and a difference between the center and surround areas of the video;

applying an envelope follower to the perceptual response signal; and

indicating the video contains visual stress scenes based on the output of the envelope follower.

2. The method of claim 1 in which detecting visual stress scenes comprises detecting contrasting scenes in temporal differences.

3. The method of claim 1 in which detecting visual stress scenes comprises detecting contrasting scenes in spatial differences.

4. The method of claim 1 in which indicating the video contains visual stress scenes comprises generating a quantitative measure.

5. A method for detecting visual stress scenes in a video, the method comprising:

receiving a video including scenes that may cause visual stress in some viewers;

generating a signal representing human perceptual response from scenes in the video;

applying an envelope follower to the perceptual response signal;

indicating the video contains visual stress scenes based on the output of the envelope follower;

converting the output of the envelope follower into a simulated EEG signal; and

comparing the simulated EEG signal with an EEG signal produced from a human response while viewing the same video.

6. A method for detecting visual stress scenes in a video, the method comprising:

receiving a video including scenes that may cause visual stress in some viewers;

generating a signal representing human perceptual response from scenes in the video;

applying an envelope follower to the perceptual response signal;

indicating the video contains visual stress scenes based on the output of the envelope follower; and

converting the output of the envelope follower to a probability measure.

7. The method of claim 6 , in which the probability measure is made for each pixel in a video frame.

8. The method of claim 7 , in which the probability measure is made for a predetermined time interval.

9. The method of claim 7 , in which the probability measure is made only for a region of interest within the video frame.

10. A method for reducing visual stress scenes in a video, the method comprising:

receiving a video including scenes that may cause visual stress in some viewers;

generating a signal representing human perceptual response from scenes in the video;

applying an envelope follower to the perceptual response signal;

reducing contrast in the video based on an output from the envelope follower; and

outputting the reduced contrast video as a reduced visual stress output.

11. The method of claim 10 in which generating a human perceptual response comprises passing the video through a spatiotemporal filter.

12. The method of claim 11 , further comprising generating a perceptual contrast portion of the perceptual response signal based on a function of a center area, a surround area, and a difference between the center and surround areas of the video.

13. The method of claim 10 , in which reducing contrast in the video comprises reducing contrast of the video in a final display device.

14. The method of claim 10 , in which reducing contrast in the video comprises reducing a maximum luminescence of at least a portion of the video.

15. The method of claim 10 , in which reducing contrast in the video comprises reducing a difference between a minimum luminescence and a maximum luminescence of at least a portion of the video.

16. The method of claim 10 , in which reducing contrast in the video comprises reducing contrast of the video in a device separate from a final display device.

17. A visual stress detector for detecting scenes of a video that may cause visual stress in a viewer, the detector comprising:

an input for receiving a video including scenes that may cause visual stress in some viewers:

a human perceptual response generator coupled to the input;

an envelope follower coupled to the human perceptual response generator;

an output for generating a signal indicating those scenes of the video may cause visual stress in the viewer; and

a mitigation circuit coupled to the envelope follower, the mitigation circuit structured to modify the video to reduce scenes that may cause visual stress to the viewer.

18. The visual stress detector of claim 17 , in which the mitigation circuit is structured to reduce contrast in the video.

19. The visual stress detector of claim 17 , further comprising:

an EEG simulation circuit coupled to the envelope follower and structured to generate a simulated EEG signal.

20. A method of verification of a device structured to detect visual stress scenes in a video, the method, comprising:

generating a signal that indicates visual stress in the video;

from the signal that indicates visual stress, generating a simulated EEG;

obtaining a measured EEG from one or more humans created while watching the video; and

comparing the measured EEG to the simulated EEG.

21. The method of claim 20 in which generating a signal that indicates visual stress in a video comprises:

generating a signal representing a human perceptual response from scenes in the video.

22. The method of claim 21 , further comprising: analyzing the signal representing the human perceptual response with an envelope follower.

23. The method of claim 20 , in which generating a simulated EEG comprises generating a unimodal map.