US6201879B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for logo hiding in images
Assignee: Massachusetts Institute of Technology
•
Filing: 1996-02-09
•
Granted: 2001-03-13
•
Expires: 2016-02-09
Abstract
Abstract A method of hiding a figure in an image replaces information from a figure-shaped portion of the image with information from another location having similar texture. The relative insensitivity of the eye to discontinuities in texture patterns having a significant high-frequency or random component minimizes the perceptibility of the replacement. The figure is revealed by autocorrelating the image containing the repeated information, and subtracting the image from a copy of itself shifted according to the arguments creating large value of the autocorrelation function.
Inventors
- 👤 Walter Bender
- 👤 Norishige Morimoto
- 👤 Daniel Gruhl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:41
CPC Classifications
G; G06; G06T; G06T1/00; G06T1/0021; G06T1/005; G06T1/0028; G06T2201/00; G06T2201/005; G06T2201/0051
Claims Analysis
Total Claims: 94
Claim 1
Independent Claim
134 words
A method of embedding an imperceptible figure in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the method comprising the steps of: a. identifying an encoding field in the original image, the encoding field having a continuous texture pattern; b. identifying in the encoding field a source portion at an original location and a target portion at a target location, the target portion not overlapping the source portion, both portions being shaped like the figure; and c. generating an altered image having identical source and target portions by copying the source portion over the target portion so as to replace parameter values in the target portion with a repeated pattern segment, thereby embedding the figure.
Claim 2
Independent Claim
134 words
A method of embedding an imperceptible figure in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the method comprising the steps of: a. identifying an encoding field in the original image, the encoding field having a continuous texture pattern; b. identifying in the encoding field a source portion at an original location and a target portion at a target location, the target portion not overlapping the source portion, both portions being shaped like the figure; and c. generating an altered image having identical source and target portions by copying the source portion over the target portion so as to replace parameter values in the target portion with a repeated pattern segment, thereby embedding the figure.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein the encoding field texture pattern has a significant high-frequency component.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the field texture pattern has a random component.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein the portions are identified by visual inspection.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the portions are chosen automatically by a computer.
Claim 7
Dependent Claim
31 words
The method of claim 1 wherein the step of identifying the encoding field is performed based on a sample variance of the parameter values assumed at points in the encoding field.
Claim 8
Dependent Claim
30 words
The method of claim 1 wherein the step of identifying the encoding field is performed based on the curvature of the parameter values assumed at points in the encoding field.
Claim 9
Dependent Claim
33 words
The method of claim 1 wherein the step of identifying the encoding field is performed based on simultaneous autoregressive model parameters derived from the parameter values assumed at points in the encoding field.
Claim 10
Dependent Claim
40 words
The method of claim 1 wherein the encoding field texture pattern has a periodic component and a random component and the step of identifying the encoding field is performed based on the relative strengths of the periodic and random components.
Claim 11
Dependent Claim
27 words
The method of claim 8 wherein the step is identifying the encoding field is based on the magnitude of a standard deviation of a Gaussian random variable.
Claim 12
Dependent Claim
34 words
The method of claim 9 wherein the step of identifying the encoding field is performed based on the ratio of the autocovariance small-displacement energy and the total energy of the encoding field texture pattern.
Claim 13
Dependent Claim
30 words
The method of claim 1 wherein the step of identifying the encoding field is performed based on the similarity of the encoding field texture pattern to an archetype texture pattern.
Claim 14
Dependent Claim
14 words
The method of claim 1 wherein the points are represented as electronically encoded pixels.
Claim 15
Dependent Claim
12 words
The method of claim 1 wherein the image is a photography backdrop.
Claim 16
Dependent Claim
15 words
The method of claim 1 further comprising the step of partitioning the image into fields.
Claim 17
Dependent Claim
22 words
The method of claim 1 further comprising the step of passing the original image through a filter before generating the altered image.
Claim 18
Dependent Claim
12 words
The method of claim 16 wherein the filter is a low-pass filter.
Claim 19
Dependent Claim
12 words
The method of claim 16 wherein the filter is a high-pass filter.
Claim 20
Dependent Claim
39 words
The method of claim 16 wherein the step of passing the original image through a filter removes a portion of the original image frequency spectrum and further comprising the step of adding the removed portion to the altered image.
Claim 21
Dependent Claim
10 words
The method of claim 1 wherein the parameter is luminance.
Claim 22
Dependent Claim
10 words
The method of claim 1 wherein the parameter is chrominance.
Claim 23
Dependent Claim
15 words
The method of claim 11 wherein the value of the ratio is greater than 20%.
Claim 24
Independent Claim
146 words
A method of embedding an imperceptible figure in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the method comprising the steps of: a. selecting in the original image a source region at an original location having a source texture pattern and a target region at a target location having a target texture pattern, the source and target texture patterns being visually similar; and b. generating an altered image by copying a source portion of the source region over a target portion of the target region, the source and target portions not overlapping and both being shaped like the figure, so as to replace parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions, thereby embedding the figure.
Claim 25
Independent Claim
146 words
A method of embedding an imperceptible figure in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the method comprising the steps of: a. selecting in the original image a source region at an original location having a source texture pattern and a target region at a target location having a target texture pattern, the source and target texture patterns being visually similar; and b. generating an altered image by copying a source portion of the source region over a target portion of the target region, the source and target portions not overlapping and both being shaped like the figure, so as to replace parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions, thereby embedding the figure.
Claim 26
Dependent Claim
20 words
The method of claim 23 wherein the source and target regions are part of an encoding field representing a substance.
Claim 27
Dependent Claim
28 words
The method of claim 23 wherein the region selection step is performed based on the similarity of the source and target texture patterns as determined by visual inspection.
Claim 28
Dependent Claim
17 words
The method of claim 23 wherein the source and target texture patterns each have a random component.
Claim 29
Dependent Claim
32 words
The method of claim 23 wherein the region selection step is performed based on the similarity of the source and target texture patterns to one another as determined automatically by a computer.
Claim 30
Dependent Claim
39 words
The method of claim 27 wherein the similarity of the source and target texture patterns to one another is determined based on the similarity of each of the source and target texture patterns to at least one archetype pattern.
Claim 31
Dependent Claim
36 words
The method of claim 28 wherein the similarity of each of the source and target texture patterns to the at least one archetype pattern is determined based on a simultaneous autoregressive model of the texture patterns.
Claim 32
Dependent Claim
34 words
The method of claim 28 wherein the similarity of each of the source and target texture patterns to the at least one archetype pattern is determined using a Wold-based model of the texture patterns.
Claim 33
Dependent Claim
29 words
The method of claim 27 wherein the similarity of the source and target texture patterns to one another is determined using a simultaneous autoregressive model of the texture patterns.
Claim 34
Dependent Claim
28 words
The method of claim 27 wherein the similarity of the source and target texture patterns to one another is determined using a Wold-based model of the texture patterns.
Claim 35
Dependent Claim
15 words
The method of claim 23 further comprising the step of partitioning the image into fields.
Claim 36
Dependent Claim
14 words
The method of claim 23 wherein the points are represented as electronically encoded pixels.
Claim 37
Dependent Claim
12 words
The method of claim 23 wherein the image is a photography backdrop.
Claim 38
Dependent Claim
22 words
The method of claim 23 further comprising the step of passing the original image through a filter before generating the altered image.
Claim 39
Dependent Claim
12 words
The method of claim 36 wherein the filter is a low-pass filter.
Claim 40
Dependent Claim
12 words
The method of claim 36 wherein the filter is a high-pass filter.
Claim 41
Dependent Claim
39 words
The method of claim 36 wherein the step of passing the original image through a filter removes a portion of the original image frequency spectrum and further comprising the step of adding the removed portion to the altered image.
Claim 42
Dependent Claim
10 words
The method of claim 23 wherein the parameter is luminance.
Claim 43
Dependent Claim
10 words
The method of claim 23 wherein the parameter is chrominance.
Claim 44
Dependent Claim
18 words
The method of claim 23 wherein the source and target texture patterns each has a significant high-frequency component.
Claim 45
Independent Claim
238 words
A method of detecting a figure embedded in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the method comprising the steps of: a. electronically encoding an altered image as an array of pixels, each having a pixel parameter value, the altered image having a source portion at an original location having a source texture pattern copied onto a target portion at a target location having a target texture pattern, the target portion not overlapping the source portion, the portions being shaped like the figure, so as to replace parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions embedding the figure; b. generating an electronically encoded copy of the altered image; c. correlating the pixel parameter values in the altered image and the copy so as to generate an indication of relative placement of the original location in the altered image with respect to the target location in the copy; d. positioning the altered image and the copy so as to align the repeated pattern segment at the target location with the original location; and e. subtracting parameter values in one of the aligned altered image and the copy from parameter values in the other of the aligned altered image and the copy so as to identify the figure.
Claim 46
Independent Claim
238 words
A method of detecting a figure embedded in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the method comprising the steps of: a. electronically encoding an altered image as an array of pixels, each having a pixel parameter value, the altered image having a source portion at an original location having a source texture pattern copied onto a target portion at a target location having a target texture pattern, the target portion not overlapping the source portion, the portions being shaped like the figure, so as to replace parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions embedding the figure; b. generating an electronically encoded copy of the altered image; c. correlating the pixel parameter values in the altered image and the copy so as to generate an indication of relative placement of the original location in the altered image with respect to the target location in the copy; d. positioning the altered image and the copy so as to align the repeated pattern segment at the target location with the original location; and e. subtracting parameter values in one of the aligned altered image and the copy from parameter values in the other of the aligned altered image and the copy so as to identify the figure.
Claim 47
Dependent Claim
93 words
The method of claim 43 wherein the step of identifying the figure at the second location comprises the steps of: a. assigning correspondences between pixels of the copy and pixels of the altered image so as to align the location in the altered image and the second location in the copy; b. subtracting the pixel values of the altered image from the corresponding pixel values of the copy to generate difference values associated with the corresponding image pixels; and c. squaring the difference values, thereby generating an output image displaying the decoded figure.
Claim 48
Dependent Claim
42 words
The method of claim 44 further comprising the step of resetting to a reset value the pixel parameter of image pixels associated with difference values having a magnitude smaller than a predetermined number so as to clarify the appearance of the figure.
Claim 49
Dependent Claim
11 words
The method of claim 43 wherein the pixel parameter is luminance.
Claim 50
Dependent Claim
11 words
The method of claim 43 wherein the pixel parameter is chrominance.
Claim 51
Independent Claim
315 words
A method of detecting a figure embedded in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, by using a filter to separate a section of the original image frequency spectrum from the original image and thereby provide a complementary original image the method comprising the steps of: a. electronically encoding an altered image as an array of pixels, each having a pixel parameter value, the altered image comprising an altered complementary image in the separated section of the original image frequency spectrum, the altered complementary image having a source portion at an original location, the source portion having a source texture pattern, copied onto a target portion at a target location, the target portion having a target texture pattern—the target portion not overlapping the source portion, the portions both being shaped like the figure—thereby replacing parameter values in the target portion with a repeated pattern segment, the altered complementary image having identical source and target portions embedding the figure; b. passing the electronically encoded altered image through the filter used to filter the original image so as to generate the altered complementary image; c. generating an electronically encoded copy of the altered complementary image; d. correlating the pixel parameter values in the altered complementary image and the copy so as to generate an indication of relative placement of the original location in the altered complementary image with respect to the target location in the copy; e. positioning the altered complementary image and the copy so as to align the repeated pattern segment at the target location with the original location; and f. subtracting parameter values in one of the aligned altered complementary image and the copy from parameter values in the other of the aligned altered image and the copy so as to identify the figure.
Claim 52
Independent Claim
315 words
A method of detecting a figure embedded in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, by using a filter to separate a section of the original image frequency spectrum from the original image and thereby provide a complementary original image the method comprising the steps of: a. electronically encoding an altered image as an array of pixels, each having a pixel parameter value, the altered image comprising an altered complementary image in the separated section of the original image frequency spectrum, the altered complementary image having a source portion at an original location, the source portion having a source texture pattern, copied onto a target portion at a target location, the target portion having a target texture pattern—the target portion not overlapping the source portion, the portions both being shaped like the figure—thereby replacing parameter values in the target portion with a repeated pattern segment, the altered complementary image having identical source and target portions embedding the figure; b. passing the electronically encoded altered image through the filter used to filter the original image so as to generate the altered complementary image; c. generating an electronically encoded copy of the altered complementary image; d. correlating the pixel parameter values in the altered complementary image and the copy so as to generate an indication of relative placement of the original location in the altered complementary image with respect to the target location in the copy; e. positioning the altered complementary image and the copy so as to align the repeated pattern segment at the target location with the original location; and f. subtracting parameter values in one of the aligned altered complementary image and the copy from parameter values in the other of the aligned altered image and the copy so as to identify the figure.
Claim 53
Dependent Claim
96 words
The method of claim 48 wherein the step of identifying the figure at the second location comprises the steps of: a. assigning correspondences between pixels of the copy and pixels of the altered complementary image so as to align the location in the altered complementary image and the second location in the copy; b. subtracting the pixel values of the altered complementary image from the corresponding pixel values of the copy to generate difference values associated with the corresponding image pixels; and c. squaring the difference values, thereby generating an output image displaying the decoded figure.
Claim 54
Independent Claim
166 words
An apparatus for embedding an imperceptible figure in an original image electronically encoded as pixels, each of which has a pixel parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the apparatus comprising: a. a computer memory for storing the original image as an ordered set of pixels; b. means for identifying an encoding field in the original image, the encoding field having a continuous texture pattern; c. means for identifying in the encoding field a source portion at an original location and a target portion at a target location, the source and target portions not overlapping and both shaped like the figure; and d. means for creating an altered image by copying the pixel parameter values of the source portion over the pixel parameter values of the target portion so as to replace the parameter values of the target portion with a repeated pattern segment, the altered image having identical source and target portions, thereby embedding the figure.
Claim 55
Independent Claim
166 words
An apparatus for embedding an imperceptible figure in an original image electronically encoded as pixels, each of which has a pixel parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the apparatus comprising: a. a computer memory for storing the original image as an ordered set of pixels; b. means for identifying an encoding field in the original image, the encoding field having a continuous texture pattern; c. means for identifying in the encoding field a source portion at an original location and a target portion at a target location, the source and target portions not overlapping and both shaped like the figure; and d. means for creating an altered image by copying the pixel parameter values of the source portion over the pixel parameter values of the target portion so as to replace the parameter values of the target portion with a repeated pattern segment, the altered image having identical source and target portions, thereby embedding the figure.
Claim 56
Dependent Claim
34 words
The apparatus of claim 50 wherein the means for identifying the encoding field identifies the encoding field based on a sample variance of the pixel parameter values assumed at pixels in the encoding field.
Claim 57
Dependent Claim
33 words
The apparatus of claim 50 wherein the means for identifying the encoding field identifies the encoding field based on the curvature of the pixel parameter values assumed at pixels in the encoding field.
Claim 58
Dependent Claim
36 words
The apparatus of claim 50 wherein the means for identifying the encoding field identifies the encoding field based on simultaneous autoregressive model parameters derived from the pixel parameter values assumed at pixels in the encoding field.
Claim 59
Dependent Claim
30 words
The apparatus of claim 53 wherein the means for identifying the encoding field identifies the encoding field based on the magnitude of a standard deviation of a Gaussian random variable.
Claim 60
Dependent Claim
42 words
The apparatus of claim 50 wherein the encoding field texture pattern has a periodic component and a random component and the means for identifying the encoding field identifies the encoding field based on the relative strengths of the periodic and random components.
Claim 61
Dependent Claim
36 words
The apparatus of claim 55 wherein the means for identifying the encoding field identifies the encoding field based on the ratio of the autocovariance small-displacement energy and the total energy of the encoding field texture pattern.
Claim 62
Dependent Claim
35 words
The apparatus of claim 56 wherein the means for identifying the encoding field does not select a field if the value of the ratio for the texture pattern of that field is less than 20%.
Claim 63
Dependent Claim
49 words
The apparatus of claim 50 further comprising a computer memory for storing at least one archetype texture pattern and wherein the means for identifying the encoding field identifies the encoding field based on the similarity of the encoding field texture pattern to the at least one archetype texture pattern.
Claim 64
Dependent Claim
14 words
The apparatus of claim 50 further comprising means for partitioning the image into fields.
Claim 65
Dependent Claim
21 words
The apparatus of claim 50 further comprising means for removing a portion of the original frequency spectrum of the original image.
Claim 66
Dependent Claim
13 words
The apparatus of claim 60 wherein the spectrum-portion-removing means is a low-pass filter.
Claim 67
Dependent Claim
13 words
The apparatus of claim 60 wherein the spectrum-portion-removing means is a high-pass filter.
Claim 68
Dependent Claim
11 words
The method of claim 50 wherein the pixel parameter is luminance.
Claim 69
Dependent Claim
11 words
The method of claim 50 wherein the pixel parameter is chrominance.
Claim 70
Independent Claim
161 words
An apparatus for embedding an imperceptible figure in an original image electronically encoded as pixels, each of which has a pixel parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the apparatus comprising: a. a computer memory for storing the original image as an ordered set of pixels; b. means for identifying in the original image a source region having a source texture pattern and a target region having a target texture pattern, the source and target texture patterns being visually similar; c. means for creating an altered image by copying pixel parameter values of a source portion of the source region over a target portion of the target region, the source and target portions not overlapping and both portions being shaped like the figure, so as to replace the parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions, thereby embedding the figure.
Claim 71
Independent Claim
161 words
An apparatus for embedding an imperceptible figure in an original image electronically encoded as pixels, each of which has a pixel parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the apparatus comprising: a. a computer memory for storing the original image as an ordered set of pixels; b. means for identifying in the original image a source region having a source texture pattern and a target region having a target texture pattern, the source and target texture patterns being visually similar; c. means for creating an altered image by copying pixel parameter values of a source portion of the source region over a target portion of the target region, the source and target portions not overlapping and both portions being shaped like the figure, so as to replace the parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions, thereby embedding the figure.
Claim 72
Dependent Claim
37 words
The apparatus of claim 65 wherein the means for identifying the regions identifies the regions based on the similarity of the source and target texture patterns as determined by a simultaneous autoregressive model of the texture patterns.
Claim 73
Dependent Claim
36 words
The apparatus of claim 65 wherein the means for identifying the regions identifies the regions based on the similarity of the source and target texture patterns as determined by a Wold-based model of the texture patterns.
Claim 74
Dependent Claim
49 words
The apparatus of claim 65 further comprising a computer memory for storing at least one archetype texture pattern and wherein the means for identifying the regions identifies the regions based on the similarity of each of the source and target texture patterns to the at least one archetype pattern.
Claim 75
Dependent Claim
41 words
The apparatus of claim 68 wherein the means for identifying the regions determines the similarity of each of the source and target texture patterns to the at least one archetype pattern based on a simultaneous autoregressive model of the texture patterns.
Claim 76
Dependent Claim
40 words
The apparatus of claim 68 wherein the means for identifying the regions determines the similarity of each of the source and target texture patterns to the at least one archetype pattern based on a Wold-based model of the texture patterns.
Claim 77
Dependent Claim
14 words
The apparatus of claim 65 further comprising means for partitioning the image into fields.
Claim 78
Dependent Claim
21 words
The apparatus of claim 65 further comprising means for removing a portion of the original frequency spectrum of the original image.
Claim 79
Dependent Claim
13 words
The apparatus of claim 72 wherein the spectrum-portion-removing means is a low-pass filter.
Claim 80
Dependent Claim
13 words
The apparatus of claim 72 wherein the spectrum-portion-removing means is a high-pass filter.
Claim 81
Dependent Claim
11 words
The apparatus of claim 65 wherein the pixel parameter is luminance.
Claim 82
Dependent Claim
11 words
The apparatus of claim 65 wherein the pixel parameter is chrominance.
Claim 83
Independent Claim
238 words
An apparatus for detecting a figure embedded in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the apparatus comprising: a. a computer memory for storing the altered image as an array of pixels, each having a pixel parameter value, the altered image having a source portion at an original location copied onto a target portion at a target location, the target portion not overlapping the source portion, the portions being shaped like the figure, so as to replace the parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions embedding the figure; b. means for generating an electronically encoded copy of the altered image; c. means for autocorrelating the pixel parameter values in the altered image and the copy so as to generate an indication of relative placement of the original location in the altered image with respect to the target location in the copy; d. means for positioning the altered image and the copy so as to align the repeated pattern segment at the target location with the original location; and e. means for subtracting pixel parameter values in one of the aligned altered image and the copy from parameter values in the other of the aligned altered image and the copy so as to identify the figure.
Claim 84
Independent Claim
238 words
An apparatus for detecting a figure embedded in an original image encoded as points, each of which has a parameter value, the image having fields over which the arrangement of parameter values generates texture patterns, the apparatus comprising: a. a computer memory for storing the altered image as an array of pixels, each having a pixel parameter value, the altered image having a source portion at an original location copied onto a target portion at a target location, the target portion not overlapping the source portion, the portions being shaped like the figure, so as to replace the parameter values in the target portion with a repeated pattern segment, the altered image having identical source and target portions embedding the figure; b. means for generating an electronically encoded copy of the altered image; c. means for autocorrelating the pixel parameter values in the altered image and the copy so as to generate an indication of relative placement of the original location in the altered image with respect to the target location in the copy; d. means for positioning the altered image and the copy so as to align the repeated pattern segment at the target location with the original location; and e. means for subtracting pixel parameter values in one of the aligned altered image and the copy from parameter values in the other of the aligned altered image and the copy so as to identify the figure.
Claim 85
Dependent Claim
96 words
The apparatus of claim 77 wherein the means for identifying the figure at the second location comprises: a. means for assigning correspondences between pixels of the copy and pixels of the altered image so as to align the location in the altered image and the second location in the copy; b. means for subtracting the pixel values of the altered image from the corresponding pixel values of the copy to generate difference values associated with the corresponding image pixels; and c. means for squaring the difference values, thereby generating an output image displaying the decoded figure.
Claim 86
Dependent Claim
41 words
The apparatus of claim 77 further comprising means for resetting to a reset value the pixel parameter of image pixels associated with difference values having a magnitude smaller than a predetermined number so as to clarify the appearance of the figure.
Claim 87
Dependent Claim
11 words
The apparatus of claim 77 wherein the pixel parameter is luminance.
Claim 88
Dependent Claim
11 words
The apparatus of claim 77 wherein the pixel parameter is chrominance.
Claim 89
Dependent Claim
21 words
The apparatus of claim 77 further comprising means for removing a portion of the original frequency spectrum of the altered image.
Claim 90
Dependent Claim
13 words
The apparatus of claim 82 wherein the spectrum-portion-removing means is a low-pass filter.
Claim 91
Dependent Claim
13 words
The apparatus of claim 82 wherein the spectrum-portion-removing means is a high-pass filter.
Claim 92
Dependent Claim
45 words
The method of claim 43 wherein pairing locations in the altered image with locations in the copy in accordance with the relative displacement constitutes the step of positioning the altered image and the copy so as to align the target location with the original location.
Claim 93
Dependent Claim
47 words
The method of claim 48 wherein pairing locations in the complementary altered image with locations in the copy in accordance with the relative displacement constitutes the step of positioning the complementary altered image and the copy so as to align the target location with the original location.
Claim 94
Dependent Claim
38 words
The apparatus of claim 77 wherein the means for positioning the altered image and the copy so as to align the target location with the original location pairs locations in the altered image with locations in the copy.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-12 | 2004-09-11 | 2005-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-12 | 2008-09-11 | 2009-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-12 | 2012-09-11 | 2013-03-13 | $7700.00 | Window Closed / Lapsed |