摘要:
Watermark data is converted to watermark coefficients, which may be embedded in an image by converting the image to a frequency domain, embedding the watermark in image coefficients corresponding to medium-frequency components, and converting the modified coefficients to the spatial domain. The watermark data is extracted from the modified image by converting the modified image to a frequency domain, extracting the watermark coefficients from the image coefficients, and determining the watermark data from the watermark coefficients. The watermark data may be truncated image data bits such as truncated least significant data bits. After extraction from the watermark, the truncated image data bits may be combined with data bits representing the original image to increase the bit depth of the image. Watermark data may include audio data portions corresponding to a video frame, reference frames temporally proximate to a video frame, high-frequency content, sensor calibration information, or other image data.
摘要:
The present disclosure provides methods and systems for processing data. One claim recites a method practiced using used a user's camera-equipped portable computer system. The method includes the acts of: capturing image data corresponding to a region using the camera of the portable computer system; applying a filter to the captured image data, in which the filter prioritizes image data at a center of the region and averages images data at a relative distance from the center region; and searching the filtered image data for hidden keys. Of course, other combinations and claims are provided as well.
摘要:
Multiple transform utilization and applications for secure digital watermarking In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
摘要:
An image processing apparatus of the present invention includes: a self-similar image storing section 13 that stores a pattern of a self-similar image; a superimposed image data generating section 15 that generates superimposed image data from a self-similar image, based on the pattern of the self-similar image; an image combining section 17 that combines original image data with the superimposed image data; and a control section 11 that controls operations of the above-mentioned sections. The superimposed image data generating section 15 adjusts a pattern of a self-similar image so that a size of a superimposed image corresponds to a draw size of an original image which draw size is determined by the control section 11. It is therefore possible to combine the original image data with the superimposed image data so that the superimposed image is suitably drawn regardless of the draw size of the original image.
摘要:
An image is encoded to define one or more spatial regions that can be sensed by a suitably-equipped mobile device (e.g., a smart phone), but are imperceptible to humans. When such a mobile device senses one of these regions, it takes an action in response (e.g., rendering an associated tone, playing linked video, etc.). The regions may overlap in layered fashion. One form of encoding employs modification of the color content of the image at higher spatial frequencies, where human vision is not acute. In a particular embodiment, the encoding comprises altering a transform domain representation of the image by adding signal energy in a first chrominance channel, where the added signal energy falls primarily within a segmented arc region in a transform domain space.
摘要:
The present disclosure relates generally to embedding auxiliary data and data hiding. One claim recites a method including: receiving data representing a media signal; using a programmed electronic processor, calculating perceptibility characteristics of the media signal, in which the perceptibility characteristics include contrast; using a programmed electronic processor, calculating a non-linear contrast to gain mapping using the perceptibility characteristics; using a programmed electronic processor, embedding an auxiliary signal in the media signal with reference to the non-linear contrast to gain mapping. Other claims and combinations are also provided.
摘要:
The implementations of digital watermarks can be optimally suited to particular transmission, distribution and storage mediums given the nature of digitally-sampled audio, video and other multimedia works. Watermark application parameters can be adapted to the individual characteristics of a given digital sample stream. Watermark information can be either carried in individual samples or in relationships between multiple samples, such as in a waveform shape. More optimal models may be obtained to design watermark systems that are tamper-resistant given the number and breadth of existent digitized sample options with different frequency and time components. The highest quality of a given content signal may be maintained as it is mastered, with the watermark suitably hidden, taking into account usage of digital filters and error correction. The quality of the underlying content signals can be used to identify and highlight advantageous locations for the insertion of digital watermarks. The watermark is integrated as closely as possible to the content signal, at a maximum level to force degradation of the content signal when attempts are made to remove the watermarks.
摘要:
An image is encoded to define one or more spatial regions that can be sensed by a suitably-equipped mobile device (e.g., a smartphone), but are imperceptible to humans. When such a mobile device senses one of these regions, it takes an action in response (e.g., rendering an associated tone, playing linked video, etc.). The regions may overlap in layered fashion. One form of encoding employs modification of the color content of the image at higher spatial frequencies, where human vision is not acute. In a particular embodiment, the encoding comprises altering a transform domain representation of the image by adding signal energy in a first chrominance channel, where the added signal energy falls primarily within a segmented arc region in a transform domain space. In another arrangement, a smartphone display presents both image data captured from a scene, and a transform representation of the image data (e.g., in the Fourier domain). This latter information can aid a user in positioning the phone, e.g., to enhance decoding of a steganographic digital watermark. In still another arrangement, foveal filtering is applied to of smartphone-captured image data in connection with other image processing.
摘要:
Disclosed is a method and system for digital watermarking of multimedia signals. The input multimedia signal is represented using an inverse difference pyramid decomposition. Spectrum coefficients may be calculated for each level of the pyramid using a new kind of complex Hadamard transform, the matrix of which is distinguished from the known ones by the fact that only one-fourth of its coefficients are complex numbers. The phases of a previously selected part of the low-frequency coefficients are modified with the watermark data, limiting the angles of the phase changes in a gap of several degrees only. After an inverse complex Hadamard Transform, the values of the coefficients from all pyramid levels are summed up and the result is the watermarked signal. The watermark can contain multiple independent levels for each level of the pyramid.
摘要:
The present disclosure relates generally to encoding and decoding signals from media signals. One claim recites an apparatus comprising: electronic memory for storing blocks of a media signal; an electronic processor programmed for: determining a detection metric for the blocks, the detection metric comprising a measure of coincidence of detection parameters of different blocks; and performing detection operations based on the measure of coincidence of the detection parameters. Of course, other claims and combinations are provided as well.