International Business Machines Corporation

Roy Lee Adler

Chai Wah Wu

Charles Philippe Tresser

Martin Aureliano Hassner

Alan David Kalvin

Joseph Y Margulies

Marco Martens

Bruce P Kitchens

Joan LaVerne Mitchell

Peter Anthony Franaszek

John Peter Moussouris

Nenad Rijavec

Gerhard Robert Thompson

Richard C Schneider

Michael I Shub

Nogah Haramati

Jean-Pierre Dedieu

Robert H Risch

Spinal modeling is based on a concept called spinal energy which assumes that the spine assumes a shape to minimize spinal energy. Spinal energy depends on parameters called stiffness coefficients. These parameters can be determined from human data which, by hypothesis, are universal for a large class of humans. The method adapts Newton's method to the manifold SO(3) to find a solution of model of the human spine. Where basins of attraction are small in Newton's method, homotopy methods are introduced to move from known solutions to unknown solutions. By setting the gradient of the spinal energy to zero, Newton's method is used to solve the inverse problem of finding stiffness coefficients from human data. A new approach to improving deformed spines uses the modeling method based on spinal energy. This approach preserves maximally the range of motion of the spine. The technique used is vertebraplasty; i.e., adding and/or subtracting material surgically from various vertebral bodies without fusing or altering soft tissue. An interactive process is used to determine the surgery to be performed to improve spinal shape.

Computation of shapes of three-dimensional linkage structures based on optimization techniques

A method and apparatus for halftoning digital images renders color data subject to constraints on the number of colorants which can be deposited on a single pixel and constraints on consecutive pixels rendered with the same color. The color data to be rendered is mapped into a second data set in an achievable color gamut space. Then, using a digital halftoning method in the achievable color gamut space, the second data set is rendered, so that the constraints are satisfied.

Constrained digital halftoning

A watermarking method involves mostly invisible artifacts and is sensitive to any modification of the picture at the level of precision rendered by the compressed version of the image. The image is compressed according to a known compression standard, such as the JPEG standard, and with a fixed quality setting. Using the JPEG standard, the original image is cut into blocks to which the Discrete Cosine Transform (DCT) is applied and the DCT coefficients quantized. The watermark according to the invention is applied to the quantized DCT coefficients. This is done using an encryption function, such as a secret key/public key algorithm. The JPEG compression is then completed using a lossless compression scheme, such as Huffman coding, to produce the compressed and watermarked image. Authentication of the compressed and watermarked image begins with a lossless decompression scheme to obtain the set of quantized DCT coefficients. The coefficients are authenticated, and the DCT output of each block is dequantized. If necessary, an inverse DCT is applied to each block to output the decompressed watermarked image.

Compressed image authentication and verification

A method and apparatus for halftoning utilizes a truly aperiodic mask with memory requirements much smaller than the mask itself. The mask is constructed of several smaller compatible masks and a selector which selects between the smaller masks. In this way the computation of a large aperiodic mask is replaced by the computation of several much smaller masks. Using this technique, watermarks may be embedded for encrypting information in such a way that the quality of the image is not compromised.

Dithering masks with very large periods

A computer system and method solve the problem of getting a useful three-dimensional representation of an object like the spine using a small amount of data. This is done by gathering three-dimensional data in the form of a set of 2D computer tomography (CT) slices of a patient's bones and a coaxial set of 2D CT scout images, which are digital two-dimensional X-ray images that can be produced by a CT scanner; extracting from each of these three-dimensional data sets a corresponding stack of 2D contours; and constructing a 3D geometric model of the object. The main features of spinal deformation are captured by integrating these two sets of three-dimensional data, and constructing from them a three-dimensional geometric model of the spine. Scouts are usually used to monitor CT scan acquisition. Here, they are also used as an essential source of data.

System and method for three-dimensional geometric modeling by extracting

A computer system and method solve the problem of getting a useful three-dimensional representation of an object like the spine using a small amount of data. This is done by gathering and combining three-dimensional data in the form of (a) a set of 2D computer tomography (CT) slices of a patient's bones with (b) a set of 2D CT scout images, which are digital two-dimensional X-ray images that can be produced by a CT scanner. The main features of spinal deformation are captured by integrating these two sets of three-dimensional data, and constructing from them a three-dimensional geometric model of the spinal. Scouts are usually used to monitor CT scan acquisition. Here, they are also used as an essential source of data.

System and method for acquiring three-dimensional data subject to

An efficient method and apparatus corrects synchronization problems in the recovery data stored on magnetic media. Resolving blocks are inserted into the unconstrained data string at specified intervals. A resolving block is constructed to do two things: reset the encoding automaton and produce in the constrained data string blocks which allow correction of synchronization. Before decoding, synchronization is corrected. The constrained data string is decoded, and then the resolving block removed. The blocks are inserted before run-length limited encoding occurs and deleted after run-length limited decoding takes place. The run-length limited encoder and decoder are unchanged.

Resolving block method for synchronization correction in run-length

A computer system and method solve the problem of getting a useful three dimensional representation of an object like the spine using a small amount of data. This is done by gathering and combining three dimensional data in the form of computer tomography (CT) scans of a patient's bones with two dimensional data consisting of CT scout images (or scouts), which are digital two dimensional X-ray images that can be produced by a CT scanner. The main features of spinal deformation are captured by combining the two dimensional data from CT scouts and the three-dimensional information from the CT scans using simple modeling of vertebrae. Scouts are usually used to monitor CT scan acquisition. Here, they are also used as an essential source of data.

System and method for accessing the three-dimensional geometry of large

Method and apparatus is described for encoding and decoding a stream of randomly distributed binary bits representing digital data, including an encoder for encoding the bit stream to achieve a run length limited, partial response coding of the stream; a recording medium for recording the encoded stream; and a decoding system for recovering timing signals and a stream of data signals separately from the recorded stream using a first channel for decoding the recorded stream to recover a timing signal stream; therefrom; and a second channel for decoding the recorded stream to recover a stream of data signals therefrom.

Dual channel partial response system

An algorithm and the hardware embodiment for producing a run length limited code useful in magnetic recording channels are described. The system described produces sequences which have a minimum of 2 zeros and a maximum of 7 zeros between adjacent 1's. The code is generated by a sequential scheme that maps 1 bit of unconstrained into 2 bits of constrained data. The encoder is a finite state machine whose internal state description requires 3 bits. It possesses the attractive feature of reset data blocks which reset it to a fixed state. The decoder requires a lookahead of three future channel symbols (6 bits) and its operation is channel state independent. The error propagation due to a random error is 3 bits. The hardware implementation is extremely simple and can operate at very high data speeds.

Method and apparatus for generating a noiseless sliding block code for a

An algorithm and the hardware embodiment for producing a run length limited code useful in magnetic recording channels are described. The system described produces sequences which have a minimum of 1 zero and a maximum of 7 zeros between adjacent 1's. The code is generated by a sequential scheme that map 2 bits of unconstrained into 3 bits of constrained data. The encoder is a finite state machine whose internal state description requires 3 bits. It possesses the attractive feature of reset data blocks which reset it to a fixed state. The decoder requires a lookahead of two future channel symbols (6 bits) and its operation is channel state independent. The error propagation due to a random error is 5 bits. The hardware implementation is extremely simple and can operate at very high data speeds.

A cryptographic system for encrypting a block of binary data under the control of a key consisting of a set of binary symbols. The cryptographic system may be utilized within a data processing environment to ensure complete privacy of data and information that is stored or processed within a computing system. All authorized subscribers who are permitted access to data within the network are assigned a unique key consisting of a combination of binary symbols. The central processing unit within the computing network contains a complete listing of all distributed authorized subscriber keys. All communications transmitted from terminal input are encrypted into a block cipher by use of the cryptographic system operating under the control of the subscriber key which is inputed to the terminal device. At the receiving station or central processing unit, an identical subscriber key which is obtained from internal tables stored within the computing system is used to decipher all received ciphered communications.

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Chappaqua, NY, United States of America

Roy Lee Adler