Abstract: A method an apparatus for modifying the play time of digital audio tracks. For each data block of samples taken from a plurality of such blocks comprising an audio stream or track, the original block data plus a time shifted copy of the block data are superimposed, in a manner dependent on either desired expansion or desired contraction of play time, to create an overlap region. The overlap region is selected at a position of best match as resulting from a normalized correlation over the overlap, the super position being weighted by a linear cross-fading function. All signal crossovers (signal transitions of opposite signal sign) in a block are located. A position at which to superimpose a copy of the data block with the data block, and the length of the data block, are determined based upon the location of said crossovers within a given data block.

Abstract: An algorithmically based method and apparatus for registering halftone color separations using edge based registration techniques and three registration points on each film separation in order to handle image stretching in both directions. Improved techniques include the use of gray level transformation, an improved U.S.C. predicate, double accuracy interpretation after systematic convolution sampling, finer angle sweeping to achieve smoother edge transitions around sharp corners, elimination of gaps in the edge continuity, enhancement of final edge linking, a more accurate and robust segment matching algorithm, invocation of a registration quality index for quality control checking of each segment picture registration, and reduction of machine cycle time by performing computations concurrently with machine movement.

Abstract: A method and apparatus for locating the centers of crosshair register marks and using the mark center locations to register the color film separations or other objects which bear the register marks. A digital picture is taken of each mark, and the picture image is transformed into a picture in which the pixels range between 0 and 1. Weighting windows are constructed and scanned over the pictures along the x and y axes to record the intensity level at each pixel location. Weighted summation calculations are then made to determine the intensity centroid location in x and y. A special screening technique is used to reject contributions of dirt, dust and other noise to enhance the accuracy.

Abstract: An algorithmic based method and apparatus for registering halftone color separations using edge based registration techniques. Digital pictures are taken at two locations on each film, and, following optimal thresholding of the data, the edges are located by application of a Laplacian of a Gaussian edge detection operator. Sampling is used to reduce the computational requirements, and full resolution is restored by interpolation. The edge locations are corrected for operator edge bias, and the corrected edge points are linked into segments which are registered by the parameter space method. The initial offset is corrected for size differences by application of least squares correction techniques.

Abstract: A method and apparatus for registering the halftone color separation films used in color picture processing. A digital picture is taken of two register points on each separation film, and the pictures (which may contain register marks) are analyzed by algorithmic processes in order to calculate the movement necessary to register the halftone picture details (or register marks). Based on the calculations, the films are punched to provide a pair of register holes in each film at locations which result in registration when the register holes are aligned on register pins during the final reproduction process. The algorithmic process involves determining the halftone screen angle, average interdot spacing and fractional area occupied by each halftone dot within its halftone cell and using this data to construct a continuous tone picture. Interpolation techniques are used to interpolate the continuous tone picture to a registration picture which is a 150 line screen picture square with the raw data picture.