Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.