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US5909516A
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Method and apparatus for decomposing an image stream into units of local contrast
Assignee: ASEV DISPLAY LABS
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Filing: 1997-03-28
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Granted: 1999-06-01
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Expires: 2017-03-28
Abstract
Abstract An apparatus and concomitant method for decomposing an image stream into units of local contrast. A temporal contrast transform (pyramid), comprises a spatial filter, a cascade of lowpass temporal filters and a plurality of subtractors and dividers. The spatial filter is followed by a cascade of lowpass temporal filters, producing a set of temporally lowpass, spatially low pass images. Adjacent filter outputs are then subtracted, producing a set of temporally bandpass (Laplacian) images. Finally, each Laplacian image is divided by a lower level temporal lowpass image, to produce a set of temporally bandpass contrast images.
Inventors
- 👤 Jeffrey Lubin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:30
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/85; H04N19/10; H04N19/102; H04N19/117; H04N19/134; H04N19/136; H04N19/14; H04N19/154; H04N19/169; H04N19/17; H04N19/172; H04N19/42; H04N19/60
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
85 words
Apparatus for computing units of local contrast from an input sequence having a plurality of signals, said apparatus comprising: a plurality of cascaded temporal filters for generating a plurality of temporal filtered signals from each of the signal of the input sequence; at least one subtractor, coupled to at least two of said temporal filters, for generating a temporal bandpass signal; and at least one divider, coupled to one of said subtractor and one of said temporal filter, for generating a temporal bandpass contrast signal.
Claim 2
Dependent Claim
85 words
Apparatus for computing units of local contrast from an input sequence having a plurality of signals, said apparatus comprising: a plurality of cascaded temporal filters for generating a plurality of temporal filtered signals from each of the signal of the input sequence; at least one subtractor, coupled to at least two of said temporal filters, for generating a temporal bandpass signal; and at least one divider, coupled to one of said subtractor and one of said temporal filter, for generating a temporal bandpass contrast signal.
Claim 3
Dependent Claim
12 words
The apparatus of claim 1, wherein said plurality of signals are images.
Claim 4
Dependent Claim
47 words
The apparatus of claim 1, further comprises: a spatial filter, coupled to one of said temporal filter, for applying spatial filtering to the image of the input sequence to generate a spatial filtered image, where said spatial filtered image is used to generate said temporal filtered signals.
Claim 5
Dependent Claim
12 words
The apparatus of claim 1, wherein said temporal filters are lowpass filters.
Claim 6
Dependent Claim
35 words
The apparatus of claim 4, wherein each of said temporal filter is expressed as: h(t)=a exp(-at) u(t) where u(t) is the unit step function u(t)=0 for t<0, else u(t)=1, and a is a fitted parameter.
Claim 7
Dependent Claim
12 words
The apparatus of claim 1, wherein said temporal filters are FIR filters.
Claim 8
Dependent Claim
22 words
The apparatus of claim 1, wherein said plurality of cascaded temporal filters, said subtractor, and said divider form a temporal contrast pyramid.
Claim 9
Dependent Claim
80 words
Method for computing units of local contrast from an input sequence having a plurality of signals, comprising the steps of: (a) using a plurality of cascaded temporal filters to generate a plurality of temporal filtered signals from each of the signal of the input sequence; (b) generating a temporal bandpass signal from adjacent set of said temporal filtered signals; and (c) dividing said temporal bandpass signal by one of said temporal filtered signals to generate a temporal bandpass contrast signal.
Claim 10
Dependent Claim
80 words
Method for computing units of local contrast from an input sequence having a plurality of signals, comprising the steps of: (a) using a plurality of cascaded temporal filters to generate a plurality of temporal filtered signals from each of the signal of the input sequence; (b) generating a temporal bandpass signal from adjacent set of said temporal filtered signals; and (c) dividing said temporal bandpass signal by one of said temporal filtered signals to generate a temporal bandpass contrast signal.
Claim 11
Dependent Claim
12 words
The method of claim 8, wherein said plurality of signals are images.
Claim 12
Dependent Claim
40 words
The method of claim 8, further comprising the step of: (a') spatial filtering the image of the input sequence to generate a spatial filtered image, where said spatial filtered image is said signal of the input sequence in step (a).
Claim 13
Dependent Claim
12 words
The method of claim 8, wherein said temporal filters are lowpass filters.
Claim 14
Dependent Claim
35 words
The method of claim 8, wherein each of said temporal filter is expressed as: h(t)=a exp(-at) u(t) where u(t) is the unit step function u(t)=0 for t<0, else u(t)=1, and a is a fitted parameter.
Claim 15
Dependent Claim
12 words
The method of claim 8, wherein said temporal filters are FIR filters.
Claim 16
Dependent Claim
69 words
Method for computing units of local contrast from an input sequence having a plurality of signals, comprising the steps of: (a) generate a plurality of temporal filtered signals from each of the signal of the input sequence; (b) generating a temporal bandpass signal from adjacent set of said temporal filtered signals; and (c) generating a temporal bandpass contrast signal from said temporal bandpass signal and said temporal filtered signals.
Claim 17
Dependent Claim
69 words
Method for computing units of local contrast from an input sequence having a plurality of signals, comprising the steps of: (a) generate a plurality of temporal filtered signals from each of the signal of the input sequence; (b) generating a temporal bandpass signal from adjacent set of said temporal filtered signals; and (c) generating a temporal bandpass contrast signal from said temporal bandpass signal and said temporal filtered signals.
Claim 18
Dependent Claim
12 words
The method of claim 14, wherein said plurality of signals are images.
Claim 19
Dependent Claim
40 words
The method of claim 14, further comprising the step of: (a') spatial filtering the image of the input sequence to generate a spatial filtered image, where said spatial filtered image is said signal of the input sequence in step (a).
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-05-31 | 2002-11-30 | 2003-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-31 | 2006-11-30 | 2007-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-31 | 2010-11-30 | 2011-06-01 | $7700.00 | Window Closed / Lapsed |