Method of indexing seizure risk due to flashing lights on video display and system therefor

• US 20040155872A1
• Filed: 06/04/2003
• Published: 08/12/2004
• Est. Priority Date: 02/12/2003
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kamijo, Kenichi
• Granted Patent: US 7,136,055 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G09G 2310/0224 Details of interlacing
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/10 Special adaptations of display systems for operation with variable images
• CPC Class Codes: G09G 3/2059 using error diffusion
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: H04N 5/144 Movement detection for video coding H04N19/503; analysis of motion in general G06T7/20
• CPC Class Codes: Y10S 348/91 Flicker reduction

Abstract

In order to generate a risk index of stress symptoms triggered by flashing lights on a scan type video display screen, a video signal processor is provided which operates such as to implement temporal filtering and spatial filtering on a video signal applied thereto every field and detect low temporal frequency components while excluding effects due to high spatial frequencies. A risk index generator receives the low frequency components from the video signal processor and determines the risk index based thereon.

Claims

1. A system for generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising:

video signal processing means for implementing temporal filtering and spatial filtering on a video signal applied thereto every field or every frame and determining temporal low frequency components which are not associated with high spatial frequencies; and

a risk index generator for determining the risk index using the temporal low frequency components issued from the video signal processing means and generating the risk index.

2. The system as claimed in claim 1, wherein the video signal to be processed at the video signal processing means is primary-color signals or a luminance signal.

3. The system as claimed in claim 1, further comprising a risk index evaluator being provided such as to receive the risk index issued from the risk index generator, the risk index evaluator filtering the risk index which continues a predetermined time period while exceeding a predetermined threshold.

4. A system for generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising:

first video signal processing means for implementing temporal filtering and spatial filtering on an incoming video signal applied thereto every field or every frame and determining temporal low frequency components which are not associated with high spatial frequencies, and generating a first video signal;

second video signal processing means for implementing temporal filtering on the incoming video signal applied thereto every field or every frame and determining temporal low frequency components, and generating a second video signal; and

a risk index generator which receives the first and second video signals and determines the risk index using the first and second video signals and generating the risk index.

5. The system as claimed in claim 4, wherein the video signal to be processed at each of the first and second video signal processing means are primary-color signals or a luminance signal.

6. The system as claimed in claim 4, further comprising a risk index evaluator being provided such as to receive the risk index issued from the risk index generator, the risk index evaluator filtering the risk index which continues a predetermined time period while exceeding a predetermined threshold.

7. A system for generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising:

a temporal low-pass filter for determining low temporal frequency components of an incoming video signal applied thereto every field or every frame;

a memory for storing the incoming video signal applied thereto every field or every frame;

a spatial frequency determiner for determining spatial frequencies of the video signal retrieved from the memory every field or every frame; and

a risk index generator which receives data from the temporal low-pass filter, the memory, and the spatial frequency determiner, and determines and generates the risk index using the received data.

8. The system as claimed in claim 7, wherein the spatial frequency determiner issues a coefficient indicating a medium value or a maximal value of the determined spatial frequencies, and applies the medium value or the maximal value to the risk index generator, and wherein the risk index generator determines the risk index using the medium value or the maximal value of the determined spatial frequencies.

9. The system as claimed in claim 7, wherein the incoming signal is primary-color signals or a luminance signal.

10. The system as claimed in claim 7, further comprising a risk index evaluator being provided such as to receive the risk index issued from the risk index generator, the risk index evaluator filtering the risk index which continues a predetermined time period while exceeding a predetermined threshold.

11. A method of generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising the steps of:

(a) implementing temporal filtering and spatial filtering on a video signal every field or every frame and determining temporal low frequency components which are not associated with high spatial frequencies; and

(b) determining the risk index using the temporal low frequency components obtained at step (a) and generating the risk index.

12. The method as claimed in claim 11, wherein the video signal is primary-color signals or a luminance signal.

13. The method as claimed in claim 11, further comprising:

evaluating the risk index determined at step (b) by filtering the risk index which continues a predetermined time period while exceeding a predetermined threshold.

14. A method of generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising the steps of:

(a) implementing temporal filtering and spatial filtering on an incoming video signal every field or every frame and determining temporal low frequency components which are not associated with high spatial frequencies;

(b) implementing temporal filtering on the incoming video signal every field or every frame and determining temporal low frequency components; and

(c) determining the risk index using the video signal processed at steps (a) and (b).

15. The method as claimed in claim 14, wherein the video signal to be processed at steps (a) and (b) is primary-color signals or a luminance signal.

16. The method as claimed in claim 14, further comprising:

evaluating the risk index determined at step (c) by filtering the risk index which continues a predetermined time period while exceeding a predetermined threshold.

17. A method of generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising;

(a) determining low temporal frequency components of an incoming video signal applied thereto every field or every frame;

(b) temporarily storing the incoming video signal applied thereto every field or every frame;

(c) determining spatial frequencies of the video signal retrieved from the memory every field or every frame; and

(d) determining the risk index using the data determined or stored at steps (a), (b), and (c).

18. The method as claimed in claim 17, wherein the incoming signal is primary-color signals or a luminance signal.

19. The method as claimed in claim 17, further comprising:

evaluating the risk index determined at step (d) by filtering the risk index which continues a predetermined time period while exceeding a predetermined threshold.

20. A method of generating a risk index of seizures induced by flashing lights on a scan type video display screen, comprising;

(a) determining low temporal frequency components of an incoming video signal applied thereto every field or every frame;

(b) temporarily storing the incoming video signal applied thereto every field or every frame;

(c) determining spatial frequencies of the video signal retrieved from the memory every field or every frame, and determining a medium value or a maximal value of the detected spatial frequencies; and

(d) determining the risk index using the data determined or stored at steps (a), (b), and (c).