Abstract: A series of approved printers is associated with each of multiples utilities. A client user having a local printer must first identify the local printer as one of the approved printers. The client user may then gain access to the utilities having an association with the local printer. The utilities have access to multiple image sets. Each image set includes a thumbnail representation for quick selection, a screen representation for editing the image, and a printer representation for printing the image. The printer representation is of higher resolution than the screen representation, and the screen representation is of higher resolution than the thumbnail representation. Each utility is further associated with list of predefined, and unalterably, printer setting. When a print option is actuated, the utility conveys is list of predefined printer settings to a printer without requiring the client user to submit any printer preferences.

Abstract: An internet presentation system includes an internet accessible server that permits access to a database of editable and executable presentation files to select users with a specific type of periphery device. The periphery device, or projector, includes a hardware ID used by the server to authenticate the user, and to update driver information for the periphery device. The server additionally maintains an administration mode by which select administrators may group and restrict the select users to specific groups of presentation files. The administrators also create and edit template files and color scheme files required, but not editable, by the select users. The server also maintain statistic of the select users and their activities. The administrators use the statistics to target template and color scheme files for deletion and editing.

Abstract: Known techniques for generating serial information to represent program objects (serialization) and to recreate program objects from the serial information (deserialization) often impose limitations on the changes that may be made to the class structure or definition of the program object. Many changes to the class structure introduce incompatibilities that prevent a one version of a program object from being recovered from serial information that represent a different version of the program object. Techniques are disclosed that overcome this difficulty by allowing the serialization and deserialization processes to be adaptive according to the version of the program object.

Abstract: Tone reproduction of an image is improved by the use of error diffusion or dithering in the mapping of input pixel values on an input values scale to printer pixel values on a printer values scale, where the input values scale and the printer values scale both have more than two levels, to generate an image where a spatial average of printer values approximates a spatial average of the corresponding input values, as measured on the printer values scale. To improve the tone reproduction of reduced-resolution images, the printer pixel values are grouped into multi-pixel cells, printer pixel values within each cell are mapped to a font index value, and a font cell corresponding to the index level is printed at the location of the cell. The font set is chosen such that differences in total deposited ink between consecutive font cells is minimized.

Abstract: Tone reproduction of an image is improved by the use of error diffusion or dithering in the mapping of input pixel values on an input values scale to printer pixel values on a printer values scale, where the input values scale and the printer values scale both have more than two levels, to generate an image where a spatial average of printer values approximates a spatial average of the corresponding input values, as measured on the printer values scale. To improve the tone reproduction of reduced-resolution images, the printer pixel values are grouped into multi-pixel cells, printer pixel values within each cell are mapped to a font index value, and a font cell corresponding to the index level is printed at the location of the cell. The font set is chosen such that differences in total deposited ink between consecutive font cells is minimized.

Abstract: An improved display of a color image is achieved by an optimum placement of color dots using an efficient stochastic screening process in which display elements are formed according to a priority ranking of color and according to a spatial-priority matrix. Various combinations of basic colors are ranked in priority according to visibility such that elements in a stochastic screen are first formed for the most visible colors. The number of elements in the screen that are used to represent more than one basic color is minimized. In preferred embodiments, a spatial-priority matrix is used to control the placement of colors in a stochastic screen such that an optimally uniform distribution of colors is achieved. A process for generating a spatial priority matrix for display devices that do not have a one-to-one display aspect ratio is described.

Abstract: An improved display of a color image is achieved by an optimum placement of color dots using an efficient stochastic screening process in which display elements are formed according to a priority ranking of color and according to a spatial-priority matrix. Various combinations of basic colors are ranked in priority according to visibility such that elements in a stochastic screen are first formed for the most visible colors. The number of elements in the screen that are used to represent more than one basic color is minimized. In preferred embodiments, a spatial-priority matrix is used to control the placement of colors in a stochastic screen such that an optimally uniform distribution of colors is achieved. A process for generating a spatial priority matrix for display devices that do not have a one-to-one display aspect ratio is described.

Abstract: A printer driver employs multi-level dither to limit the size of a look-up table required for its color-correction operation. To suppress some of the resultant artifacts, a filter operation precedes the half-toning operation used to produce the printer input signal. The computation cost of the filter operation is modest because it uses an infinite-impulse-response filter.

Abstract: A technique for reducing image artifacts is described. The technique includes utilizing a clustered-dot dither matrix having a plurality of layers with each of the layers arranged in one of a plurality of complementary patterns within the dither matrix. By using a dither matrix which generates layers of dots in complementary patterns, image banding artifacts and ink bleeding characteristics resulting from a printer generating a halftone image using a clustered-dot dithering technique are reduced.

Abstract: In generating instructions for a printer to render a digitally represented image, addresses for a color-correction look-up table that sparsely samples the source-image color space are generated from the source image by multi-level dithering, and no interpolation is performed to generate the color-corrected image from the values thus fetched from the table, even though it samples the source-image color space only sparsely. In a system in which dithering is also used to generate display commands from the corrected image's pixel values, the effective color resolution is essentially the same as that which would have resulted from interpolation instead of table-look-up-input dithering, but the computation cost is significantly less.

Abstract: The binary, on-or-off commands for a binary scan-line-oriented display are obtained by half-toning through the use of a dither matrix of the clustered-dot variety. But in "tiling" the display surface with the replicated dither matrix, successive columns of the dither matrices are offset from each other, in the direction transverse to the scan direction, by a fraction of the cluster-row spacing. This reduces the banding artifacts that otherwise result from non-uniform scan-line spacing.

Abstract: An ink-jet-printer driver employs clustered-dot dither to generate binary image signals that represent an image that has been adjusted for the ink-duty limit that must be imposed to avoid bleeding on some print media. Some image values that would result in ink duties that exceed the limit without adjustment are actually reduced by more than needed to meet the ink-duty limit. The resultant adjusted value is an increasing function of unadjusted value even for unadjusted values that exceed the ink-duty limit. To impose the limit, a Bayer dither process (94) receives an input that represents the ratio of ink-limit-adjusted ink duty to unadjusted ink duty. A gating operation (96) permits an ink request only at those locations where both dither processes (92 and 94) indicate that an ink is permitted.

Abstract: To impose a total-ink duty-cycle limitation by an ink-jet printer that substitutes black ink for simultaneous occurrences of cyan, magenta, and yellow, a printer driver determines a component-value adjustment as a function of the difference between a color's maximum and average component values. Adjusting the color values when this quantity is high but not when it is low enables one to prevent violation of the total-ink duty-cycle limit without unduly limiting black-ink use.

Abstract: A method and apparatus for selectively depositing ink on a recording medium is described. The method and apparatus implement a technique in which portions of a clustered-dot dither matrix are identified and no ink is deposited under any circumstances in the so-identified portions. The portions are organized into a relatively large dispersed distribution matrix within the clustered-dot dither matrix.

Abstract: In a computer system (10) that employs an ink-jet printer (12), a printer driver (36) receives signals from an applications program (34) that describes an image in multiple-bit pixel values. The driver converts the multiple-bit-per-pixel representation into the binary-pixel-value format necessary to operate the printer. In so doing, it submits the image values I(x,y) to complementary weighting processes (136 and 138). It then applies clustered-dot dithering to one of the weighting-process outputs and distributed-dot dithering to the other weighting-process output, and it commands the printer to apply ink at any pixel for which the output of either dithering step calls for it. Except at the highest pixel values, the weighting is such that the overall output is the same as that which clustered-dot dithering produces. At the highest pixel values, the results tend increasingly toward those of dispersed-dot dithering as the input value in-creases.

Abstract: An ink-jet-printer driver employs clustered-dot dither to generate binary image signals that represent an image that has been adjusted for the ink-duty limit that must be imposed to avoid bleeding on some print media. To impose the limit, a Bayer dither process (94) receives an input that represents the ratio of ink-limit-adjusted ink duty to unadjusted ink duty. A gating operation (96) permits an ink request only at those locations where both dither processes (92 and 94) indicate that an ink is permitted.

Abstract: A controller for an ink-jet printer (26) half-tones three color-component values in clustered-dot dither operations (80, 82, and 84) that employ respective dither arrays whose cluster centers are displaced from each other. Additionally, a half-toning operation (86) is performed on a fine-resolution black value obtained from the color-component values in an undercolor-removal operation (59) in which the resultant black value is less, throughout most of the component-value range, than the minimum of the color-component values from which the black value is derived. The banding effects that would otherwise result from ink bleeding are thereby greatly reduced. The banding effects can be further reduced by performing black-component half-toning in a non-cluster-dot-dither operation, without detracting significantly from the intended clustered-dot dither effect.

Abstract: To convert the multiple-bit-resolution intensity information for a color component of a given pixel into the ink-on or ink-off command required to control a printer, the source values for different pixels are compared with thresholds in a "dither matrix" of different thresholds for different pixels, and a given pixel is printed if the source value exceeds the dither-matrix value for that pixel. Different dither matrices are employed for different color components, with the result that lighter-color areas have a smoother appearance than they would result if a common dither matrix were employed for all color components.