Abstract: The invention is a novel watermark in a media sequence and systems and methods for embedding and detecting the watermark. Different watermarks from a watermark set of pseudo random watermarks are selected (randomly or by a selection pattern) and each selected watermark is embedded in a different selected I-frame set of the media stream. Identifying the known sequence of watermarks in the stream of I-frames of a copy can identify the video stream from which the copy originates.

Abstract: The invention is a novel watermark in a media sequence and systems and methods for embedding and detecting the watermark. Different watermarks from a watermark set of pseudo random watermarks are selected (randomly or by a selection pattern) and each selected watermark is embedded in a different selected I-frame set of the media stream. Identifying the known sequence of watermarks in the stream of I-frames of a copy can identify the video stream from which the copy originates.

Abstract: The present invention provides methods and apparatus for embedding an identifying pattern of visible speckles into the digitized image of each page of a document. A speckle is a cluster of black or white pixels. Speckles are printed as black speckles on the white paper, or conversely, as areas of missing black removed from the black text characters, called white speckles. The collective pattern of all embedded black and white speckles on a single document page is called a specklemark. A specklemark can survive contrast manipulations on photocopiers and binary rasterization done by fax scanning prior to data transmission. The random pattern of the black and white speckles visible in the digitized image of a document page can be detected automatically, and by systematically matching the detected pattern with those known to have been embedded into marked copies of a document page, a specific document copy can be identified.

Abstract: The present invention provides methods and apparatus for embedding an identifying pattern of visible speckles into the digitized image of each page of a document. A speckle is a cluster of black or white pixels. Speckles are printed as black speckles on the white paper, or conversely, as areas of missing black removed from the black text characters, called white speckles. The collective pattern of all embedded black and white speckles on a single document page is called a specklemark. A specklemark can survive contrast manipulations on photocopiers and binary rasterization done by fax scanning prior to data transmission. The random pattern of the black and white speckles visible in the digitized image of a document page can be detected automatically, and by systematically matching the detected pattern with those known to have been embedded into marked copies of a document page, a specific document copy can be identified.

Abstract: The present invention provides an image watermarking technique whereby a watermark is inserted into an adjusted digital source image that is bounded by a specific bounding rectangle. If the source image is larger than the rectangle, its dimensions are reduced by a common factor until it is the largest adjusted image that lies totally within the rectangle. A watermark is inserted into the adjusted image and at least one derived image of larger or smaller size is produced. Then, regardless of the size of an image derived from the watermarked adjusted image, enlarging or reducing that image to again lie within the rectangle greatly facilitates detection of the imbedded watermark. The size of the bounding rectangle may be specific to each source image, or, conversely, a common bounding rectangle may be used for a group of source images.

Abstract: A watermarking scheme is provided that allows the watermarked image to be authenticated by an authentication agent without revealing the human-readable content of the image. There is disclosed an approach that combines privacy control with watermarking and authentication mechanisms. The watermark can be made to be imperceptible to humans. Public key cryptography allows the authentication agent to authenticate without being able to watermark an image. Watermark information may also be encoded in a vector graphics image that includes at least one stroke defined by coordinate values of an ordered sequence of points. This may be obtained by providing watermark information as a bit sequence, identifying one or more redundant properties of the image, modifying the redundant properties based upon the bit sequence to generate a representation of the image and storing the representation of the image for subsequent use.

Abstract: The present invention provides methods and apparatus for imparting a multiplicity of watermarks onto a digitized image. The image includes a plurality of pixels, wherein each of the pixels includes brightness data that represents one brightness value if the image is monochrome, or a plurality of brightness data values if the image has multiple colors. In one aspect it provides for imparting more than one watermark into the digitized image comprising the steps of providing the digitized image, and multiplying the brightness data associated with at least one of the image pixels by a plurality of predetermined brightness multiplying value. Another aspect of the present invention is to provide a method for generating a composite watermark and imparting on a plurality of copies of a digitized image a different composite watermark into each copy. Also provided is a method for detecting one or more of the watermarks in the composite.

Abstract: A digital watermarking method encodes different pairs of watermarks into each of a plurality of images offered for use by a vendor. The watermarks in each pair are derived from two separate collections of watermarks and sufficiently different so as to prevent false positives. Because each pair of watermarks is assigned to a different customer relative to a particular image, unauthorized use of a digital image sold to a customer may be determined by locating the associated pair of watermarks assigned to the customer in the image. Collusion detection is also realized by forming each pair of masks from sub-collections of masks which are detectable in an image formed by combining the same images sold to one or more customers.

Abstract: The present invention provides methods and apparatus for imparting a multiplicity of watermarks onto a digitized image. The image includes a plurality of pixels, wherein each of the pixels includes brightness data that represents one brightness value if the image is monochrome, or a plurality of brightness data values if the image has multiple colors. In one aspect it provides for imparting more than one watermark into the digitized image comprising the steps of providing the digitized image, and multiplying the brightness data associated with at least one of the image pixels by a plurality of predetermined brightness multiplying value. Another aspect of the present invention is to provide a method for generating a composite watermark and imparting on a plurality of copies of a digitized image a different composite watermark into each copy. Also provided is a method for detecting one or more of the watermarks in the composite.

Abstract: A system for placing a visible "watermark" on a digital image is disclosed, wherein an image of the watermark is combined with the digital image. The pixels of the watermark image are examined, and for each pixel whose value is not a specified "transparent" value, the corresponding pixel of the original image is modified by changing its brightness but its chromaticities. This results in a visible mark which allows the contents of the image to be viewed clearly, but which discourages unauthorized use of the image.

Abstract: A system and method for fourier transform coding of data on peak limited channels using a redundancy scheme. The system and method section the data to be transmitted into contiguous blocks having sequence lengths of 2N. Each block is coded in the frequency domain and its Inverse Discrete Fourier Transform (IDFT) for each coded block is computed. The IDFT blocks are then clipped at predetermined peak values .+-. P to thereby derive clipping error values. The magnitude of the clipping error values is then determined. The magnitude squared values of the clipping error is summed for each block. If the sum exceeds a threshold .phi. for a given block, then, the block is transmitted X number of times, where X is a fixed number, each time using less than the prescribed power for the transmission, otherwise, a continuous signal is transmitted whose sampled values at the Nyquist rate are the clipped values of the IDFT for that particular block.

Abstract: A system and method for improving the quality of the output of a full-color image on a reproduction device, such as a display on a monitor or printout from a printer, that only consists of a small number of colors in comparison to the number of colors represented by the input signals. The disclosure involves specifying a new quantization method for multi-color images, rendered with orthogonal or separable color image palettes, that takes advantage of the calculations done by error diffusion. Accordingly, the image input signals are processed using the quantization error generated by one color component of a given pixel to influence the quantization of subsequent color components of the same pixel, and in such a way that the color image, so rendered, appears less grainy.

Abstract: Digital data defining images are stored in a multiplane buffer. The buffer may store plural images by restricting data corresponding to an image or image portion to storage in less than half the bit planes of the buffer. An image is displayed by reading data from the buffer and selectively passing only a portion of the data read to a display. The data defining the images may be converted from facsimile (single bit per pixel) to gray scale format (multiple bits per pel) before being written to the buffer. The conversion relies on a table storing data definitive of the effect, on the image, of a facsimile transition (1/0 ot 0/1) as a function of the location of the transition. Conversion from facsimile to gray scale is effected by examining the facsimile data for data transmission and summing the effect of each of the transitions to convert a segment of facsimile data to gray scale data.A system is also disclosed for rapidly converting an image in run-end form to a reduced-resolution gray-tone image.

Abstract: A binary image is reduced in size by a method including the steps of: storing the image in bit sequence; dividing the image into transposable blocks; transposing by look up table, for each block having any nonzero data, each group of 6 bits along a first axis to a group of 5 bits; transposing by look up table, for each block having any nonzero data, each group of 6 bits along a second axis to a group of 5 bits; storing said transposed blocks.

Abstract: A method for rotation of a binary image by 180 degrees, includes the steps of: positioning first and second address pointers at the center of at the beginning and end respectively of an image to be rotated; indexing the first pointer in a first direction through said image; indexing the second pointer in a second direction through said image; exchanging, for each index step, a first image word at the first pointer with a second image word, at the second pointer if the first image word and the second image word have any two bits with different values; reversing all exchanged words; storing the reversed, exchanged words at said pointer locations; repeating the above steps until the first pointer and the second pointer have been indexed through all words in the image at which point the image has been rotated by 180 degrees.

Abstract: An electronic processing system for reproducing mixed images, i.e., original images having areas of continuous tone and areas of text, in such a manner that both areas are of balanced, good quality in the reproduction. The image to be reproduced is (1) divided into non-overlapping 4.times.4 blocks of pixels or picture elements, and, (2) each block is classified as either of TEXT or IMAGE, based on the values of the 16 pixels within it. The classification is improved by (3) eliminating short runs of blocks with the same classification. The pixel values are then adjusted by appropriately (4) thresholding those in the TEXT blocks and, (5) averaging those in the IMAGE blocks. The IMAGE block values are quantized to one of 17 levels using an improved error diffusing process and then mapped onto a 4.times.4 pattern preparatory to (6) merging the binary images for the TEXT and IMAGE areas.

Abstract: The method of the present invention reduces a binary digital image in size by a factor F by a method including the steps of: storing the image in bit sequence; removing one or more rows of bits along the vertical axis of the image to convert i rows of bits to j rows of bits where 0.5i.ltoreq.j<i; modifying a line adjacent to each line discarded to preserve selected information from the discarded line; repeating the steps of removing and modifying a predetermined number of times to achieve a reduction by a factor F1 along the vertical axis; rotating the image in a first direction by ninety degrees; removing one or more rows of bits along the original horizontal axis of the image to convert i rows of bits to j rows of bits where 0.5i.ltoreq.

Abstract: A method for rotating an image by 90 degrees includes the steps of: storing the image in a raster format arranged in r rows by c columns, image information in each row being stored in a number of bytes, each byte having b bits, there being c/b bytes in each row of the raster format; moving a block of the image into a temporary storage, there being r rows by v columns in the block; separating each image block into groups of bytes of rotatable size; determining for each group if all bits are the same value; rotating each group that does not have all bits the same value; storing each rotated group in an output area of the raster storage; repeating the above steps for all remaining blocks of the image.

Abstract: A method for expanding a binary image includes the steps of: storing the image in bit sequence; inserting for each string of 5 bits along a first axis one or more expansion bits, to convert each said string of 5 bits to a string of 6 bits; assigning a value to each expansion bit generated by the above step; inserting one or more rows of expansion bits for each 5 rows of bits along a second axis of the image to convert each 5 rows of bits to 6 rows of bits along the second axis of the image; assigning a value to each expansion bit generated by the above steps; storing the enlarged image generated by the above steps.