Spatially-varying flicker detection
First Claim
Patent Images
1. An imaging system comprising:
- an image module configured to produce image frames at a frame rate F, the image module being configured to capture first and second portions of each of the image frames, each of the first and second portions comprising a two-dimensional array of pixels having a plurality of horizontal pixels and a plurality of vertical pixels, the first portion being separate from the second portion, the image frames including a plurality of candidate images having different exposure durations;
a frequency determination module, communicatively coupled to the image module, configured to determine frequency components associated with the first and second portions over a plurality, N, of the image frames;
a flicker analysis module, communicatively coupled to the frequency determination module, configured to determine whether any frequency component associated with the first portion or the second portion, respectively, is indicative of perceptible flicker such that the flicker analysis module is capable of determining a frequency component indicative of perceptible flicker over less than an entire area of the image frames; and
a stitch module configured to replace the first portion of a first image frame with a first portion of a second image frame from the plurality of candidate images, the first portion of the first image frame corresponding to the first portion in the second image frame, the first portion of the first image being either underexposed or overexposed, and the first portion of the second image being properly exposed.
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Accused Products
Abstract
An imaging system includes: an image module configured to produce image frames at a frame rate F, the image module being configured to capture first and second portions of each of the image frames at different times; a frequency determination module, communicatively coupled to the image module, configured to determine frequency components associated with the first and second portions over a plurality, N, of the image frames; and a flicker analysis module, communicatively coupled to the frequency determination module, configured to determine whether any of the frequency components of the first and second portions are indicative of perceptible flicker.
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Citations
25 Claims
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1. An imaging system comprising:
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an image module configured to produce image frames at a frame rate F, the image module being configured to capture first and second portions of each of the image frames, each of the first and second portions comprising a two-dimensional array of pixels having a plurality of horizontal pixels and a plurality of vertical pixels, the first portion being separate from the second portion, the image frames including a plurality of candidate images having different exposure durations; a frequency determination module, communicatively coupled to the image module, configured to determine frequency components associated with the first and second portions over a plurality, N, of the image frames; a flicker analysis module, communicatively coupled to the frequency determination module, configured to determine whether any frequency component associated with the first portion or the second portion, respectively, is indicative of perceptible flicker such that the flicker analysis module is capable of determining a frequency component indicative of perceptible flicker over less than an entire area of the image frames; and a stitch module configured to replace the first portion of a first image frame with a first portion of a second image frame from the plurality of candidate images, the first portion of the first image frame corresponding to the first portion in the second image frame, the first portion of the first image being either underexposed or overexposed, and the first portion of the second image being properly exposed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A flicker detection system comprising:
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an image module configured to produce image frames at a frame rate F, the image module being configured to capture first and second portions of each of the image frames, each of the first and second portions comprising a two-dimensional array of pixels having a plurality of horizontal pixels and a plurality of vertical pixels, the first portion being separate from the second portion, the image frames including a plurality of candidate images having different exposure durations; downsampling means, communicatively coupled to the image module, for spatially downsampling the image frames to produce downsampled image frames each having third and fourth distinct regions including the first and second portions, respectively, each of the third and fourth regions corresponding to less than all of respective image frames; frequency determination means, communicatively coupled to the downsampling means, for applying a Fourier transform to a plurality, N, of the downsampled image frames to produce separate indications of frequency components of the third and fourth portions, respectively; flicker analysis means, communicatively coupled to the frequency determination means, for analyzing the indications of frequency components to determine whether any of the frequency components corresponds to a predominant signal in the respective region, corresponds to at least one frequency of concern, and would be perceptible to a person viewing the image frames; and stitch means for replacing the first portion of a first image frame with a first portion of a second image frame from the plurality of candidate images, the first portion of the first image frame corresponding to the first portion in the second image frame, the first portion of the first image being either underexposed or overexposed, and the first portion of the second image being properly exposed. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A computer program product residing on a non-transitory processor-readable medium and comprising instructions configured to cause a processor to:
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produce image frames at a frame rate F and with first and second portions of each of the image frames being captured, each of the first and second portions comprising a two-dimensional array of pixels having a plurality of horizontal pixels and a plurality of vertical pixels, the first portion being separate from the second portion, the image frames including a plurality of candidate images having different exposure durations; determine frequency components associated with the first and second portions over a plurality, N, of the image frames; determine whether any frequency component associated with the first portion or the second portion, respectively, is indicative of perceptible flicker such that the instructions are configured to cause the processor to determine a frequency component indicative of perceptible flicker over less than an entire area of the image frames; and assemble a composite image frame by adding the first portion of a first image frame to a second image frame from the plurality of candidate images in place of the first portion of the second image frame, the first portion of the second image frame being either underexposed or overexposed, and the first portion of the first image frame being properly exposed. - View Dependent Claims (21, 22)
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23. A method of detecting flicker in image frames, the method comprising:
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producing the image frames at a frame rate F, and with first and second portions of each of the image frames being captured, each of the first and second portions comprising a two-dimensional array of pixels having a plurality of horizontal pixels and a plurality of vertical pixels, the first portion being separate from the second portion, the image frames including a plurality of candidate images having different exposure durations; determining a first frequency component associated with the first portion and a second frequency component, inequal to the first frequency component, associated with the second portion of the image frames; determining whether at least one of the first frequency component associated with the first portion or the second frequency component associated with the second portion is indicative of perceptible flicker; and replacing the first portion of a first image frame with the first portion of a second image frame from the plurality of candidate images, the first portion of the first image frame corresponding with first portion of the second image frame, the first portion of the first image being either underexposed or overexposed, and the first portion of the second image being properly exposed. - View Dependent Claims (24, 25)
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Specification