Detecting Double JPEG Compression in Images
AssigneeNew Jersey Institute of Technology
InventorsYun-Qing Shi, ChunHua Chen
Life of this patent
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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.
Claims20
A computer-readable storage medium storing computer-executable instructions to process a JPEG image, the computer-executable instructions comprising:
- receiving the JPEG image for analysis;
- extracting a 2-dimensional (2-D) array of JPEG coefficients from the JPEG image;
- generating a 2-D difference array based on the 2-D array of JPEG coefficients, wherein entries in the 2-D difference array reflect relative changes in values of pairs of entries in the 2-D array of JPEG coefficients;
- modeling the 2-D difference arrays using a Markov random process;
- and
- evaluating whether the random process reveals statistical artifacts in the JPEG image, the statistical artifacts resulting from double JPEG impression performed on the JPEG image.
A system for processing a JPEG image comprising:
- a computer readable storage medium storing computer-executable instructions for processing the JPEG image;
- a processor that is configured by the computer executable instructions to:
- receive the JPEG image for analysis;
- extract a 2-dimensional (2-D) array of JPEG coefficients from the JPEG image;
- generate a 2-D difference array based on the 2-D array of JPEG coefficients, wherein entries in the 2-D difference array reflect relative changes in values of pairs of entries in the 2-D array of JPEG coefficients;
- model the 2-D difference arrays using a random process;
- and
- evaluate whether the random process reveals statistical artifacts in the JPEG image, the statistical artifacts resulting from double JPEG impression performed on the JPEG image.
A computer-implemented method for processing a JPEG image, the method comprising:
- receiving the JPEG image for analysis to determine whether the JPEG image exhibits statistical artifacts associated with double JPEG compression;
- extracting a 2-dimensional (2-D) array of JPEG coefficients from the JPEG image;
- generating a plurality of 2-D difference arrays based on the array of JPEG coefficients, wherein the 2-D difference arrays include a first difference array and a second difference array, wherein entries in the first difference array reflect relative changes in values of pairs of entries in the 2-D array of JPEG coefficients taken along a first dimension of the JPEG image, and wherein entries in the second difference array reflect relative changes in values of pairs of entries in the 2-D array of JPEG coefficients taken along a further dimension of the JPEG image;
- applying thresholding to elements within the plurality of 2-D difference arrays;
- modeling thresholded elements of the 2-D difference arrays using a random process;
- and
- evaluating whether the random process reveals statistical artifacts in the JPEG image, the statistical artifacts resulting from double JPEG impression performed on the JPEG image.
Dependencies are inferred from the claim text.