Massachusetts Institute of Technology

Daniel Gruhl

Walter R Bender

Norishige Morimoto

A technique for embedding a mark in an a printed image allows its interpretation by an inexpensive printing system. Values of a characteristic parameter are altered in a portion of the host image confined to a thread, i.e. a region of contiguous points in the image, small enough to be included in the print space treated by the printer in a single pass of the printing head.

Method and apparatus for data hiding in printed images

A technique for embedding a tracking number as a series of bits in a printed image alters characteristic parameter values at a set of pseudo-random locations chosen for each bit in an embedding zone. The alteration markedly changes the expectation value of some linear combination of mathematical functions of the values at that set of locations. A marker bit encoded to a higher certainty than other bits in the string aids in orienting the zones in decoding. The tracking number is detected and identified by exploiting the behavior of sums of a large number of random variables, based on the Patchtrack approach.

Method and apparatus for multi-bit zoned data hiding in printed images

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.

Method and apparatus for logo hiding in images

A method of hiding information in a host audio signal introduces one or more echoes into the signal. The separation in time between the host signal and an echo is associated with the value of a datum embedded in the signal. The identity of the embedded datum is determined by observing the delay between the host signal and the echo.

Method and apparatus for echo data hiding in audio signals

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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Daniel Gruhl