US6501518B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for reducing flicker effects from discharge lamps during pipelined digital video capture
Assignee: Intel Corp
•
Filing: 1998-07-28
•
Granted: 2002-12-31
•
Expires: 2018-07-28
Abstract
Abstract A method for eliminating the flicker of a light source such as a florescent light having the first step of setting a first frame rate for the capture of a series of frames. Then, setting a capture integration period to a first integration period, and capturing a set of frames under an illumination source with a first frequency. Thereafter, determining the first frequency of the illumination by using a Fourier transform (FFT) of the set of captured frames. What is also disclosed is an apparatus for performing the above method having an image sensor and a capture control unit coupled to the image sensor.
Inventors
- 👤 Ronald D. Smith
- 👤 Gregory W. Starr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:41
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/745
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
119 words
A method comprising: setting a first frame rate; setting a capture integration period to a first integration period; capturing a set of frames under an illumination source with a first frequency; and, determining said first frequency of said illumination by generating for each of said set of frames a time sequence of row averaged data values, each value comprising an average of a separate row of image data in one frame of said set of frames to mitigate an effect of choosing a particular column of image data for said determination, performing a time to frequency domain transformation on said time sequence of row averaged data values and detecting said first frequency from a resulting spectrum of said transformation.
Claim 2
Independent Claim
119 words
A method comprising: setting a first frame rate; setting a capture integration period to a first integration period; capturing a set of frames under an illumination source with a first frequency; and, determining said first frequency of said illumination by generating for each of said set of frames a time sequence of row averaged data values, each value comprising an average of a separate row of image data in one frame of said set of frames to mitigate an effect of choosing a particular column of image data for said determination, performing a time to frequency domain transformation on said time sequence of row averaged data values and detecting said first frequency from a resulting spectrum of said transformation.
Claim 3
Dependent Claim
23 words
The method of claim 1 , further comprising setting said capture integration period to a second integration period based on said first frequency.
Claim 4
Dependent Claim
37 words
The method of claim 2 , where said setting said capture integration period comprises: choosing a set of integration periods based on said first frequency; and determining said second integration period from said set of integration periods.
Claim 5
Dependent Claim
23 words
The method of claim 3 , where said set of integration periods is chosen to substantially reduce any effects from said illumination source.
Claim 6
Dependent Claim
12 words
The method of claim 1 , where said transformation is a fast-Fourier-transform.
Claim 7
Dependent Claim
15 words
The method of claim 1 , where said first frequency is substantially at 60 Hz.
Claim 8
Dependent Claim
15 words
The method of claim 1 , where said first frequency is substantially at 50 Hz.
Claim 9
Dependent Claim
15 words
The method of claim 1 , where said first frequency is substantially at 0 Hz.
Claim 10
Independent Claim
134 words
An apparatus comprising: an image sensor; and, a capture control unit coupled to said image sensor to: set a first frame rate; set a capture integration period to a first integration period; capture a set of frames under an illumination source with a first frequency using said image sensor; and, determine said first frequency of said illumination, by sequentially generating for each of said set of frames a set of row averaged data values, each value having an average of a row of image data in one frame of said set of frames to mitigate an effect of choosing a particular column of image data for said determination, performing a time to frequency domain transformation on said set of row averaged data and detecting said first frequency from a resulting spectrum of said transformation.
Claim 11
Independent Claim
134 words
An apparatus comprising: an image sensor; and, a capture control unit coupled to said image sensor to: set a first frame rate; set a capture integration period to a first integration period; capture a set of frames under an illumination source with a first frequency using said image sensor; and, determine said first frequency of said illumination, by sequentially generating for each of said set of frames a set of row averaged data values, each value having an average of a row of image data in one frame of said set of frames to mitigate an effect of choosing a particular column of image data for said determination, performing a time to frequency domain transformation on said set of row averaged data and detecting said first frequency from a resulting spectrum of said transformation.
Claim 12
Dependent Claim
29 words
The apparatus of claim 8 , where said capture control unit is to further set said capture integration period to a second integration period based on said first frequency.
Claim 13
Dependent Claim
42 words
The apparatus of claim 10 , where said capture control unit is to set said capture integration period by choosing a set of integration periods. based on said first frequency; and determining said second integration period from said set of integration periods.
Claim 14
Dependent Claim
30 words
The apparatus of claim 11 , where said capture control unit is to choose said set of integration period so as to substantially reduce any effects from said illumination source.
Claim 15
Dependent Claim
12 words
The apparatus of claim 9 , where said transformation is a fast-fourier-transform.
Claim 16
Dependent Claim
15 words
The apparatus of claim 9 , where said first frequency is substantially at 60 Hz.
Claim 17
Dependent Claim
15 words
The apparatus of claim 9 , where said first frequency is substantially at 50 Hz.
Claim 18
Dependent Claim
15 words
The apparatus of claim 9 , where said first frequency is substantially at 0 Hz.
Claim 19
Independent Claim
151 words
An apparatus comprising: an image sensor; an analog-to-digital processor coupled to said image sensor; a flicker detector coupled to said analog-to-digital processor to determine a frequency of scene illumination by performing a frequency transform on a set of row averaged data values that are selected to mitigate an effect of choosing a particular column of image data for said determination, each value being an average of a separate row in one frame of a plurality of frames provided by the analog to digital processor using the image sensor, to generate a spectrum, and analyze the spectrum to detect a dominant spectral component; and a capture control unit coupled to said flicker detector and to said image sensor to receive an indication of a type of said scene illumination, and in response operate the image sensor in a pipelined mode in which an image is captured on a now by row basis.
Claim 20
Independent Claim
151 words
An apparatus comprising: an image sensor; an analog-to-digital processor coupled to said image sensor; a flicker detector coupled to said analog-to-digital processor to determine a frequency of scene illumination by performing a frequency transform on a set of row averaged data values that are selected to mitigate an effect of choosing a particular column of image data for said determination, each value being an average of a separate row in one frame of a plurality of frames provided by the analog to digital processor using the image sensor, to generate a spectrum, and analyze the spectrum to detect a dominant spectral component; and a capture control unit coupled to said flicker detector and to said image sensor to receive an indication of a type of said scene illumination, and in response operate the image sensor in a pipelined mode in which an image is captured on a now by row basis.
Claim 21
Dependent Claim
49 words
The apparatus of claim 17 , where said flicker detector comprises: a buffer and processing unit coupled to said analog-to-digital processor; a fast Fourier transform unit,coupled to said buffer and processing unit; and, a detector unit coupled to said buffer and processing unit and said fast Fourier transform unit.
Claim 22
Dependent Claim
50 words
The apparatus of claim 17 , wherein the capture control unit is to operate the image sensor by setting a capture integration period of the sensor based on the determined frequency of scene illumination so as to substantially reduce any visible effect from said illumination source in the captured image.
References Cited (Backward Citations)
EP0506031A1
Cited
US5495313A
Cited
JPH06209427A
Cited
US5548398A
Cited
US5960153A
Cited
JPH0965198A
Cited
US5925875A
Cited
JPH10136267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-12-30 | 2006-07-01 | 2006-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-30 | 2010-07-01 | 2010-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-30 | 2014-07-01 | 2014-12-31 | $7700.00 | Window Closed / Lapsed |