METHOD AND DEVICE FOR IDENTIFYING WHETHER STANDARD PICTURE CONTAINS WATERMARK
First Claim
1. A method for identifying whether a standard picture contains a watermark, comprising:
- at a device having one or more processors and memory;
obtaining a set of sample standard pictures;
adjusting sample standard pictures in the set of sample standard pictures to a preset size, the sample pictures in the set of sample standard pictures not containing watermark information;
calculating an average of pixel attribute values of the sample pictures in the set of sample standard pictures at pixel positions of the preset size;
normalizing the average of the pixel attribute values at the pixel positions of the preset size;
obtaining watermark-presence probabilities of the pixel positions of the preset size, wherein the watermark-presence probability of the pixel positions of the preset size is defined as a complementary event probability of a probability expressed by the average of the pixel attribute values at the pixel positions of the preset size;
obtaining a target picture that is adjusted to the preset size; and
calculating a sum of products of pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size;
in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is greater than a predefined threshold value, determining that the target picture contains a watermark, and providing a predefine output prompt indicating detection of the watermark for the target picture; and
in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is not greater than the predefined threshold value, determining that the target picture does not contain a watermark, and performing a transaction based on the target picture.
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Accused Products
Abstract
A method for identifying whether a standard picture contains a watermark is provided. After obtaining a set of sample standard pictures, one or more sample pictures in the set of sample standard pictures are adjusted to a preset size. The sample pictures in the set of sample standard pictures do not contain watermark information. Next, an average of pixel attribute values of the sample pictures at pixel positions of the preset size is calculated. The average of the pixel attribute values at the pixel positions of the preset size is normalized to obtain the watermark-presence probabilities of the pixel positions of the preset size. Then, a target picture is adjusted to the preset size and a sum of products of pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probability are calculated. Finally, it is determined whether the target picture contains a watermark according to the sum of products.
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Citations
20 Claims
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1. A method for identifying whether a standard picture contains a watermark, comprising:
at a device having one or more processors and memory; obtaining a set of sample standard pictures; adjusting sample standard pictures in the set of sample standard pictures to a preset size, the sample pictures in the set of sample standard pictures not containing watermark information; calculating an average of pixel attribute values of the sample pictures in the set of sample standard pictures at pixel positions of the preset size; normalizing the average of the pixel attribute values at the pixel positions of the preset size; obtaining watermark-presence probabilities of the pixel positions of the preset size, wherein the watermark-presence probability of the pixel positions of the preset size is defined as a complementary event probability of a probability expressed by the average of the pixel attribute values at the pixel positions of the preset size; obtaining a target picture that is adjusted to the preset size; and calculating a sum of products of pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size; in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is greater than a predefined threshold value, determining that the target picture contains a watermark, and providing a predefine output prompt indicating detection of the watermark for the target picture; and in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is not greater than the predefined threshold value, determining that the target picture does not contain a watermark, and performing a transaction based on the target picture. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device for identifying whether a standard picture contains a watermark, comprising:
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one or more processors; and memory storing instructions, the instructions, when executed by the one or more processors, cause the processors to perform; obtaining a set of sample standard pictures; adjusting sample standard pictures in the set of sample standard pictures to a preset size, the sample pictures in the set of sample standard pictures not containing watermark information; calculating an average of pixel attribute values of the sample pictures in the set of sample standard pictures at pixel positions of the preset size; normalizing the average of the pixel attribute values at the pixel positions of the preset size; obtaining watermark-presence probabilities of the pixel positions of the preset size, wherein the watermark-presence probability of the pixel positions of the preset size is defined as a complementary event probability of a probability expressed by the average of the pixel attribute values at the pixel positions of the preset size; obtaining a target picture that is adjusted to the preset size; and calculating a sum of products of pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size; in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is greater than a predefined threshold value, determining that the target picture contains a watermark, and providing a predefine output prompt indicating detection of the watermark for the target picture; and in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is not greater than the predefined threshold value, determining that the target picture does not contain a watermark, and performing a transaction based on the target picture. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A non-transitory computer-readable storage medium for identifying whether a standard picture contains a watermark, the computer-readable storage medium storing instructions, the instructions, when executed by one or more processors, cause the processors to perform:
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obtaining a set of sample standard pictures; adjusting sample standard pictures in the set of sample standard pictures to a preset size, the sample pictures in the set of sample standard pictures not containing watermark information; calculating an average of pixel attribute values of the sample pictures in the set of sample standard pictures at pixel positions of the preset size; normalizing the average of the pixel attribute values at the pixel positions of the preset size; obtaining watermark-presence probabilities of the pixel positions of the preset size, wherein the watermark-presence probability of the pixel positions of the preset size is defined as a complementary event probability of a probability expressed by the average of the pixel attribute values at the pixel positions of the preset size; obtaining a target picture that is adjusted to the preset size; and calculating a sum of products of pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size; in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is greater than a predefined threshold value, determining that the target picture contains a watermark, and providing a predefine output prompt indicating detection of the watermark for the target picture; and in accordance with a determination that the sum of products of the pixel attribute values of the target picture at the pixel positions of the preset size and the corresponding watermark-presence probabilities at the pixel positions of the preset size is not greater than the predefined threshold value, determining that the target picture does not contain a watermark, and performing a transaction based on the target picture. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification