Abstract: Briefly, in accordance with one embodiment, a method of identifying marked images based at least in part on frequency domain coefficient differences is disclosed.

Abstract: Embodiments of the invention are directed toward methods for steganalysis that improve the detection of steganography in texture images. The methods combine features extracted from the image spatial representation and from a block discrete cosine transform (BDCT) representation with multiple different block sizes (i.e., N×N) to improve detection of data hidden in texture images. Image data that is to undergo steganalysis can be provided to embodiments of the invention in at least one of spatial (pixel) and JPEG format. When JPEG format is provided, the image is first decompressed to spatial representation, from which the features are extracted when the block size is at least one 2×2, 4×4, and 16×16. When the block size is 8×8, the JPEG coefficients (JPEG quantized 8×8 BDCT coefficients) derived directly from the JPEG image are used to extract features. In addition, the method is also effective as a universal steganalyzer for both texture and smooth/non-texture images.

Abstract: Briefly, embodiments of a method of identifying marked images, in which higher order statistical moments based at least in part on a JPEG array are employed, is described

Abstract: The subject matter disclosed herein relates to techniques for detecting tampering of digital image data.

Abstract: Methods and apparatus are provided for subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of wavelet coefficients; selecting at least one bit plane between a least significant bit plane and a most significant bit plane of the matrix of wavelet coefficients; compressing the at least one selected bit plane to produce free space in the at least one selected bit plane; embedding hidden data in the free space of the at least one compressed bit plane; and subjecting the at least one embedded bit plane to an Inverse IWT to produce a marked pixel domain image. Methods and apparatus are also provided for reversing this process.

Abstract: Briefly, embodiments of a method of identifying marked images, in which higher order statistical moments based at least in part on a JPEG array are employed, is described.

Abstract: An apparatus and method for steganalysis that enhances the ability to detect distortion introduced by data hiding. In embodiments of the invention, a pixel grayscale value in an image is predicted by using its neighboring grayscale values of neighboring pixels. Further, a prediction-error image is produced by subtracting the image from its predicted image. The prediction-error image may is employed to remove at least some variations in image data other than those associated with data hiding an thus, at least partially offsets variations from image aspects other than data hiding.

Abstract: The subject matter disclosed herein relates to techniques for detecting tampering of digital image data.

Abstract: Briefly, in accordance with one embodiment, a method of identifying marked content is described. For example, although claimed subject matter is not limited in this respect, in one embodiment, a class-wise non-principal components approach may be employed.

Abstract: Data may be embedded in rows of text by modulating inter-word spaces in a row. Inter-word spaces in a particular row may be divided into two or more sets of (approximately) equal spacing. The inter-word spaces of one or more of the sets may then be modified to embed data.

Abstract: A method is provided which comprises providing a block of IWT (integer wavelet transform) coefficients for preferably one high frequency sub-band of an image; determining a mean value of said coefficients within said block; and establishing an encoded mean value to embed one of a logical-0 bit value and a logical-1 bit into said first block.

Abstract: A system and method are disclosed which may include subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of IWT coefficients; selecting a plurality of the IWT coefficients for incorporation of information therein; and setting signs for the plurality of selected IWT coefficients according to bit values of a plurality of respective data bits. The system and method can also include subjecting a marked pixel domain image to an Integer Wavelet Transform to obtain a matrix of wavelet coefficients; selecting a plurality of the coefficients from the matrix that contain embedded information; and for each selected coefficient, extracting the data bit embedded in the coefficient, a bit value of the extracted data bit determined based on a sign of the coefficient.

Abstract: Methods for reversible data hiding are disclosed herein. These methods may be applied to images for reversible image data hiding. In one embodiment, a method for reversible data hiding comprises identifying carrier data having a plurality of components and establishing prediction-errors for each of the components of the carrier data. A first threshold and a second threshold are established. The prediction-errors of the components are evaluated against the first threshold to identify components for possible hiding. The components identified for possible hiding are evaluated against the second threshold to identify components for hiding. To-be embedded data is embedded into the carrier data identified for hiding to create marked data. The marked data is evaluated for overflow or underflow. If overflow or underflow is detected, histogram modification is performed. Marked data is then established.

Abstract: Techniques described herein are generally related to steganalysis of suspect media. Steganalysis techniques may include receiving instances of suspect media as input for steganalytic processing. A first set of quantized blocks of data elements may be identified within the media, with this first set of blocks being eligible to be embedded with steganographic data. A second set of quantized blocks of data elements may be identified within the media, with this second set of blocks being ineligible to be embedded with steganographic data. The steganalysis techniques may requantize the first and second blocks. In turn, these techniques may compare statistics resulting from requantizing the first block with statistics resulting from requantizing the second block. The steganalysis techniques may then assess whether the first block of data elements is embedded with steganographic features based on how the statistics of the second blocks compare with the statistics of the first blocks.

Abstract: Techniques are generally described to determine whether a JPEG image has undergone two compressions. Probabilities can be computed for the first digits of quantized DCT (discrete cosine transform) coefficients from a set of AC (alternate current) modes to detect or determine whether the JPEG image has undergone two compressions. The set of AC modes may include a predetermined number of distinguishable AC modes where a distinguishable AC mode may be an AC mode in which a second quantization step (QS2) is not an integer multiple of the first quantization step (QS1). Classifiers may be created during a training process, and later may be used to assist in determining whether a suspect JPEG image has undergone two compressions. When the classifiers support a multi-classification system, described detection techniques may also be arranged to determine a primary quality factor for the double compressed JPEG image.

Abstract: Implementations of the detection of double MPEG compression using digit based statistics are disclosed.

Abstract: Techniques are generally described for detecting double JPEG compression in images. Example detection techniques of double JPEG compression may include receiving JPEG images for analysis and extracting 2-dimensional (2-D) arrays of JPEG coefficients from the images. 2-D difference arrays may be generated from the array of JPEG coefficients, with the entries in the difference array reflecting relative changes in values of pairs of entries in the array of JPEG coefficients. The detection techniques also model the difference arrays using random processes, and evaluate whether the random processes reveal statistical artifacts in the JPEG images. These statistical artifacts result from double JPEG impression performed on the JPEG images.

Abstract: A method of hiding data comprising creating a histogram of an attribute of a first data set. The histogram includes occurrences of the attribute. Two adjacent occurrences are selected where a count of one of the two adjacent occurrences is zero. A second data set is embedded in data of the first data set associated with the selected adjacent occurrences.

Abstract: An apparatus and method for steganalysis that enhances the ability to detect distortion introduced by data hiding. In embodiments of the invention, a pixel grayscale value in an image is predicted by using its neighboring grayscale values of neighboring pixels. Further, a prediction-error image is produced by subtracting the image from its predicted image. The prediction-error image may is employed to remove at least some variations in image data other than those associated with data hiding an thus, at least partially offsets variations from image aspects other than data hiding.

Abstract: Briefly, embodiments of a method and system for steganalysis are disclosed.