Method and apparatus for data hiding in images
First Claim
1. A method of embedding data in an image encoded as points, each point having a parameter value, the method comprising the steps of:
- a. generating an ordered series of pseudo-random numbers;
b. assigning each pseudo-random number of the series to a first or a second group;
c. associating each pseudo-random number with a point;
d. designating each point associated with a pseudo-random number assigned to the first group to be a first point each point associated with a pseudo-random number assigned to the second group to be a second point; and
e. altering the image byi. increasing the parameter value of each first point and of a first patch of points surrounding each first point andii. decreasing the parameter value of each second point and of a second patch of points surrounding each second point,thereby embedding data in the image.
1 Assignment
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Accused Products
Abstract
A method of hiding a pattern in a host image increases and decreases parameter values at randomly selected host image locations assigned to respective first and second groups. The alteration modifies the statistical behavior of a test statistic equivalent to a linear combination of a large number of instances of respective functions, associated with the pattern, of the parameter values at first and second group locations. The presence or absence of the pattern in a test image is determined by comparing the experimental value of the test statistic associated with the pattern with the expected value of the same sum for an unaltered host image.
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Citations
85 Claims
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1. A method of embedding data in an image encoded as points, each point having a parameter value, the method comprising the steps of:
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a. generating an ordered series of pseudo-random numbers; b. assigning each pseudo-random number of the series to a first or a second group; c. associating each pseudo-random number with a point; d. designating each point associated with a pseudo-random number assigned to the first group to be a first point each point associated with a pseudo-random number assigned to the second group to be a second point; and e. altering the image by i. increasing the parameter value of each first point and of a first patch of points surrounding each first point and ii. decreasing the parameter value of each second point and of a second patch of points surrounding each second point, thereby embedding data in the image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of embedding a pattern in a host image electronically encoded as points, each point having a parameter value, the method comprising the steps of:
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a. generating an ordered series of pseudo-random numbers; b. assigning each pseudo-random number of the series to a first or a second group; c. mapping a grid comprising an array of cells onto the host image by assigning groups of adjacent points to the cells; d. associating each pseudo-random number with a cell in the host image, each group of points assigned to a cell so associated with a pseudo-random number being designated a patch; e. further designating each patch in the host image associated with a pseudo-random number assigned to the first group to be a first patch and each patch in the host image associated with a pseudo-random number assigned to the second group to be a second patch; and f. altering the host image by increasing the parameter values of points in each first patch and decreasing the parameter values of points in each second patch, thereby embedding the pattern in the host image. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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49. A method for determining whether a test image, encoded as points, each point having a parameter value, contains a pattern embedded in a host image by altering the host image by increasing and decreasing the parameter values of host image points designated as respective first and second host image points according to an association of each first or second point with a pseudo-random number of a series, of which each number is assigned to a first or a second group, the method comprising the steps of:
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a. providing the series of pseudo-random numbers and assignment of each number to the first or the second group; b. associating each pseudo-random number with a point in the test image; c. designating each point in the test image associated with a pseudo-random number assigned to the first group to be a first point and each point associated with a pseudo-random number assigned to the second group to be a second point; and d. calculating a value of a test statistic, comprising the parameter values at the first and second points in the test image, formulated to reflect the pattern, the test statistic indicating whether the pattern is present in the test image. - View Dependent Claims (50, 51, 52, 53, 54, 55, 56, 57)
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58. An apparatus for embedding data in an image, the apparatus comprising:
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a. a computer memory for storing the image as an ordered set of pixels, each pixel having a pixel parameter value; b. means for generating a series of ordered pseudo-random numbers; c. means for assigning each pseudo-random number to a first or a second group; d. means for associating each pseudo-random number with a pixel and designating each pixel associated with a pseudo-random number assigned to the first group to be a first pixel and each pixel associated with a pseudo-random number of the second group to be a second pixel; and e. means for creating an altered image by i. increasing the pixel parameter value of each first pixel and of a first patch of pixels surrounding each first pixel and ii. decreasing the pixel parameter value of each second pixel and of a second patch of pixels surrounding each second pixel, thereby embedding data in the image. - View Dependent Claims (59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69)
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70. An apparatus for determining whether a test image, electronically encoded as points, each point having a parameter value, contains a pattern embedded in a host image by associating each number of a pseudo-random series with a point in the host image, each number being assigned to a first or a second group, and designating each point in the host image associated with a pseudo-random number assigned to the first group to be a first point and each point associated with a pseudo-random number assigned to the second group to be a second point, and altering the host image by increasing the parameter value of each first point in the host image and decreasing the parameter value of each second point in the host image, the apparatus comprising:
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a. means for providing the series of pseudo-random numbers and assignment of each number to the first or second group; b. means for associating each pseudo-random number with a point in the test image; c. means for designating each point in the test image associated with a pseudo-random number assigned to the first group to be a first point and each point associated with a pseudo-random number assigned to the second group to be a second point; d. means for calculating a test statistic, comprising the parameter values at the first and second points in the test image, formulated to reflect the pattern. - View Dependent Claims (71, 72, 73, 74, 75, 76, 77, 84, 85)
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- 78. An image created by altering a host image comprised of points, each point having a parameter value, by associating each number of a pseudo-random series with a point, each number being assigned to a first or a second group, and designating each point associated with a pseudo-random number assigned to the first group to be a first point and each point associated with a pseudo-random number assigned to the second group to be a second point, and increasing the parameter value of each first point and decreasing the parameter value of each second point.
Specification