Abstract: A method for controlling a multi-user interactive display system including a soft-copy display including at least an information display region and a command control region, and a digital image capture system positioned to capture a time sequence of images of users located in a field-of-view of the soft-copy display. A time sequence of images is analyzed to detect a plurality of users, and at least one of the users is designated to be a controlling user. The captured images are displayed in the command control region, wherein the detected users are demarked using graphical elements. The captured time sequence of images is analyzed to detect a gesture made by the controlling user and content displayed in the information display region is updated accordingly.

Abstract: A method and apparatus for mapping a first color space into a second color space which allows a user to specify or constrain the mapping for a subset of the points within the first color space and determine the remaining unconstrained points according to a preexisting or default mapping.

Abstract: A method for halftoning a multi-channel digital color image having an x,y array of color pixel values, includes the steps of: providing a matrix of dither values for each color channel of the digital color image wherein two or more of the matrices of dither values are designed jointly to minimize a visual cost function; for each color channel modularly addressing the matrix of dither values with the location of a pixel in the digital color image to obtain an addressed dither value; comparing the addressed dither value for each color channel with the pixel value for the corresponding color channel to determine an output halftone image value for each color channel; and repeating steps b and c for each pixel in the digital image.

Abstract: A method for halftoning a multi-channel digital color image having an x,y array of color pixel values, includes the steps of: providing a matrix of dither values for each color channel of the digital color image wherein two or more of the matrices of dither values are designed jointly to minimize a visual cost function; for each color channel modularly addressing the matrix of dither values with the location of a pixel in the digital color image to obtain an addressed dither value; comparing the addressed dither value for each color channel with the pixel value for the corresponding color channel to determine an output halftone image value for each color channel; and repeating steps b and c for each pixel in the digital image.

Abstract: A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized; comprises the steps of transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness; applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.

Abstract: A device gamut boundary surface in a device independent color space (DICS) is defined by a set of small triangles. Each triangle in the DICS corresponds to a triangle on the surface of a 3D or 4D color cube in a device dependent color space (DDCS). The triangles in the DICS are derived based on a look-up table which can be obtained by measuring a set of color patches produced from the given device. A small set of carefully selected gamut boundary points in the DICS are determined, and their corresponding points or signals on the surface of the color cube in the DDCS are computed. These data are stored in a table called a gamut descriptor. Points in a gamut descriptor can be determined by a convex polyhedral cone inclusion process, and their corresponding points in the DDCS can be determined by triangle interpolation. The gamut descriptor usually includes gamut boundary points at a number of lightness layers along a series of predetermined hue angles.