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Patent US5974159A successfully refreshed from Google Patents.
US5974159A
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Method and apparatus for assessing the visibility of differences between two image sequences
Assignee: ASEV DISPLAY LABS
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Filing: 1997-03-28
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Granted: 1999-10-26
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Expires: 2017-03-28
Abstract
Abstract A method and apparatus for assessing the visibility of differences between two input image sequences. The apparatus comprises a visual discrimination measure having a retinal sampling section, a plurality of temporal filters and a spatial discrimination section. The retinal sampling section applies a plurality of transformations to the input image sequences for simulating the image-processing properties of human vision. The temporal filters separate the sequences of retinal images into two temporal channels producing a lowpass temporal response and a bandpass temporal response. The spatial discrimination section applies spatial processing to the temporal responses to produce an image metric which is used to assess the visibility of differences between the two input image sequences.
Inventors
- 👤 Jeffrey Lubin
- 👤 Michael Henry Brill
- 👤 Aalbert de Vries
- 👤 Olga Finard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:59
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/50; H; H04; H04N; H04N19/00; H04N19/10; H04N19/102; H04N19/117; H04N19/134; H04N19/154; H04N19/169; H04N19/17; H04N19/172; H04N19/186; H04N19/60; H04N19/80; H04N19/85
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
69 words
Apparatus for assessing visibility of differences between two input image sequences having a plurality of input images, where each of said input images contains a chrominance component, said apparatus comprising: a temporal filter for filtering the chrominance components of each of the input image sequences into a lowpass temporal response; and a spatial discriminator, coupled to said temporal filter, for generating an image metric from said lowpass temporal responses.
Claim 2
Dependent Claim
69 words
Apparatus for assessing visibility of differences between two input image sequences having a plurality of input images, where each of said input images contains a chrominance component, said apparatus comprising: a temporal filter for filtering the chrominance components of each of the input image sequences into a lowpass temporal response; and a spatial discriminator, coupled to said temporal filter, for generating an image metric from said lowpass temporal responses.
Claim 3
Dependent Claim
69 words
The apparatus of claim 1, wherein each of said input images further contains a luminance component, wherein said temporal filter filters said luminance components of each of the input image sequences into a second lowpass temporal response and a bandpass temporal response, wherein said spatial discriminator generates an image metric from said lowpass and bandpass temporal responses from both the luminance and chrominance components of the input image sequences.
Claim 4
Dependent Claim
45 words
The apparatus of claim 2, further comprises: a retinal sampler, coupled to said temporal filter, for sampling each of the input image sequences to produce a retinal sampled image sequence, where said input image sequence to said temporal filter is said retinal sampled image sequence.
Claim 5
Dependent Claim
117 words
The apparatus of claim 3, wherein said retinal sampler comprises: a frame adjuster for resampling each of the input image sequences to produce a frame adjusted image sequence; a first sampler, coupled to said frame adjuster, for resampling said frame adjusted image sequence to produce an angular subtended image sequence; a border inserter, coupled to said first sampler, for inserting a border around each image of said angular subtended image sequence; a second sampler, coupled to said border inserter, for resampling said bordered image sequence from said border inserter to produce a smoothed/interpolated image sequence; and a convolver, coupled to said second sampler, for approximating optics of a human eye to produce said retinal sampled image sequence.
Claim 6
Dependent Claim
51 words
The apparatus of claim 2, wherein said temporal filter comprises: a first temporal filter, coupled to said spatial discriminator, for filtering the chrominance components of the first input image sequence; and a second temporal filter, coupled to said spatial discriminator, for filtering the chrominance components of the second input image sequence.
Claim 7
Dependent Claim
54 words
The apparatus of claim 5, wherein said temporal filter further comprises: third and fourth temporal filters, coupled to said spatial discriminator, for filtering the luminance components of the first input image sequence; and fifth and sixth temporal filters, coupled to said spatial discriminator, for filtering the luminance components of the second input image sequence.
Claim 8
Dependent Claim
39 words
The apparatus of claim 6, wherein said temporal filters are expressed as: ##EQU20## where c=Δt 1 /Δt, N(1)=(aΔt) -1 ln(1000), N(2)=15(bΔt) -1 and (n=1,2) where n=1 correlates said lowpass temporal response and where n=2 correlates said bandpass temporal response.
Claim 9
Dependent Claim
53 words
The apparatus of claim 2, wherein said spatial discriminator comprises: a contrast transform for computing a contrast pyramid having a plurality of levels for each image of said lowpass and bandpass temporal responses; and a gain control, coupled to said contrast transform, for applying cross masking of visual threshold to said contrast pyramids.
Claim 10
Dependent Claim
107 words
The apparatus of claim 8, wherein said spatial discriminator further comprises: a normalizer, coupled between said contrast transform and said gain control, for applying a weighing factor to each of said plurality of levels of said contrast pyramid to produce a normalized output; a transducer, coupled to said gain control, for applying a sigmoid non-linearity to said normalized output from said gain control to produce a transducer output; and a distancer, coupled to said transducer, for computing a distance between a plurality of m-dimensional vectors to produce said image metric, where each of said m-dimensional vectors represents a spatial position of each image of said transducer output.
Claim 11
Dependent Claim
67 words
The apparatus of claim 9, wherein said spatial discriminator further comprises: a spatially oriented filter, coupled between said contrast transform and said normalizer, for applying orientation tuning to each of said level of said contrast pyramid to produce a spatially oriented output; and a pooler, coupled between said transducer and said distancer, for averaging said transducer output over a kernel of pixels to produce a pooled output.
Claim 12
Dependent Claim
116 words
Apparatus for assessing visibility of differences between two input image sequences having a plurality of input images, said apparatus comprising: a temporal filter for filtering each of the input image sequences into a lowpass temporal response and a bandpass temporal response; and a spatial discriminator, coupled to said temporal filter, for generating an image metric from said lowpass and bandpass temporal responses, where said spatial discriminator comprises a contrast transform for computing a contrast pyramid having a plurality of levels for each image of said lowpass and bandpass temporal responses and where said spatial discriminator further comprises a gain control, coupled to said contrast transform, for applying cross masking of visual threshold to said contrast pyramids.
Claim 13
Dependent Claim
116 words
Apparatus for assessing visibility of differences between two input image sequences having a plurality of input images, said apparatus comprising: a temporal filter for filtering each of the input image sequences into a lowpass temporal response and a bandpass temporal response; and a spatial discriminator, coupled to said temporal filter, for generating an image metric from said lowpass and bandpass temporal responses, where said spatial discriminator comprises a contrast transform for computing a contrast pyramid having a plurality of levels for each image of said lowpass and bandpass temporal responses and where said spatial discriminator further comprises a gain control, coupled to said contrast transform, for applying cross masking of visual threshold to said contrast pyramids.
Claim 14
Dependent Claim
27 words
The apparatus of claim 11, wherein each of said input images contains a chrominance component and wherein said lowpass temporal response includes a chrominance lowpass temporal response.
Claim 15
Independent Claim
63 words
A method of assessing visibility of differences between two input image sequences having a plurality of input images, where each of said input image contains a chrominance component, said method comprising the steps of: (a) filtering the chrominance components of each of the input image sequences into a lowpass temporal response; and (b) discriminating said lowpass temporal responses to generate an image metric.
Claim 16
Independent Claim
63 words
A method of assessing visibility of differences between two input image sequences having a plurality of input images, where each of said input image contains a chrominance component, said method comprising the steps of: (a) filtering the chrominance components of each of the input image sequences into a lowpass temporal response; and (b) discriminating said lowpass temporal responses to generate an image metric.
Claim 17
Dependent Claim
44 words
The method of claim 13, further comprising the steps of: (a') generating a set of color coordinates for each image pixel of said input image from said input image sequences, where said input image sequences to said filtering step (a) comprises said color coordinates.
Claim 18
Dependent Claim
55 words
The method of claim 14, wherein said generating step (a') comprises the steps of: (a'1) generating CIE (Commission Internationale de l'Eclairage) coordinates for each image pixels of said input image from the input image sequences; (a'2) transforming said CIE coordinates into cone responses; and (a'3) generating said set of color coordinates from said cone responses.
Claim 19
Dependent Claim
20 words
The method of claim 15, wherein said set of color coordinates of step (a'3) is expressed as: yb=(S/Y)-(S/Y).sub.D65 and rg=(L/Y)-(L/Y).sub.D65.
Claim 20
Dependent Claim
20 words
The method of claim 15, wherein said set of color coordinates of step (a'3) is expressed as: yb=S and rg=(L-M).
Claim 21
Dependent Claim
49 words
The method of claim 13, where each of the input image further contains a luminance component, where said filtering step (a) further comprises the steps of: (a1) filtering the luminance components of each of the input image sequences into a second lowpass temporal response and a bandpass temporal response.
Claim 22
Dependent Claim
46 words
The method of claim 18, wherein said discriminating step (b) comprises the steps of: (b1) generating a contrast pyramid having a plurality of levels for each image of said lowpass and bandpass temporal responses; and (b2) applying cross masking of visual threshold to said contrast pyramids.
Claim 23
Dependent Claim
41 words
The method of claim 19, further comprising the step of: (a") sampling each of the input image sequences to produce a retinal sampled image sequence, where said input image sequences to said filtering step (a) are said retinal sampled image sequences.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-10-25 | 2003-04-26 | 2003-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-25 | 2007-04-26 | 2007-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-25 | 2011-04-26 | 2011-10-26 | $7700.00 | Window Closed / Lapsed |