Abstract: In an image processing method, on the basis of input image data with respect to a target pixel, independent multi-level data (g0, g1) corresponding to respective plural species of dots which are different in at least one of a density and a diameter are generated, and then data (O0, O1) relating to an amount of generation of the dots with respect to the target pixel are generated on the basis of a relationship between the generated independent multi-level data (g0, g1) corresponding to the plural species of dots. The image processing method is effective in performing design having a high degree of flexibility in proper use of a relatively high power dot (high density dot or large dot) and a relatively low power dot (low density dot or small dot) and can realize obviation or alleviation of an occurrence of granulation or an apparent frame caused due to the relatively high power dot.

Abstract: A novel image forming apparatus which makes gray-scale by performing at least one of operations including a manipulation of a plurality of dots arranged in a form of matrix, a single-dot-based density adjustment, or a single-dot-based size adjustment, includes a dot status detector and a density adjuster. The dot status detector detects an occurrence in which a dot exists at a focus dot position and no dot exists at positions immediately adjacent to the focus dot position in the main scaning direction. The density adjuster adjusts a writing level of the dot at the focus dot position so as to make the gray-scale smooth when the dot status detector detects the occurrence.

Abstract: A novel image forming apparatus which makes gray-scale by performing at least one of operations including a manipulation of a plurality of dots arranged in a form of matrix, a single-dot-based density adjustment, or a single-dot-based size adjustment, includes a dot status detector and a density adjuster. The dot status detector detects an occurrence in which a dot exists at a focus dot position and no dot exists at positions immediately adjacent to the focus dot position in the main scanning direction. The density adjuster adjusts a writing level of the dot at the focus dot position so as to make the gray-scale smooth when the dot status detector detects the occurrence.

Abstract: Input gray-scale bit map information is inputted to an image forming position extracting unit for extracting image forming position information. An input computer-formed image is inputted to an image forming position extracting unit for generating an image forming position. At an image forming position overlapping unit, two image forming positions are overlapped with each other, and the composed image forming position is sent to a pixel value calculating unit and an image forming position determining unit. The image value calculating unit measures a width of the composed image forming position and converts the measured value into a pixel value. The image forming position determining unit calculates a barycenter of the composed image forming position. The pixel value and the barycenter are sent as image information. Encoding without distortion can be executed by enhancing the precision of the barycenter.

Abstract: A method, associated software and resulting printing plate having both solid and halftone areas comprising ink cells. Ink cells may be provided in the solid areas according to a first pattern with a first density and size of cells per unit area, and in the halftone areas superposed on selected numbers of halftone dots. The selection of halftone dots with superposed ink cells may be according to a second pattern with a second density and size of cells in the halftone area that is a function of halftone dot size and that may or may not be be related to the first pattern.

Abstract: A method for generating a screened representation of an image, includes the steps of: (a) generating a first dot of the screened representation, wherein the first dot has a first dot size of at least two microdots; (b) repeating the dot generation step until a first number of the first dots are generated; (c) arranging the first number of dots in a frequency modulated pattern; (d) selecting a second number of second dots out of the first dots, wherein the second number is at most equal to the first number and larger than zero; and (e) enlarging the second dots by adding one or more microdots to each of the second dots.

Abstract: Xerox Reference No. D/A0639A system and method for improving xerographic halftoning by magnifying a threshold array, interpolating the in-between values, enabling multiple thresholds to be accessed simultaneously and presented to multiple comparators, to cause multi-bit output. A threshold array is sampled at distinct locations separated by the sparse sampling distance to allow warping of the threshold array dots by adjusting the sampling distance in small, fractional portions (deltas) of the magnified distance. By adding more thresholds, amplitude or intensity modulation is used to move dot edges in a process direction for further flexibility in printing irrational or warpable screens.

Abstract: A threshold mask for converting a contone image to a halftone image defines halftone cells that define halftone dots that undergo a growth in population as tone levels increase. After some growth in population, the halftone cells define halftone dots that then grow in size from a first predetermined size as tone levels increase further. During the growth in population, the halftone dots having a second predetermined size are placed into halftone gaps. The second predetermined size is smaller than the first predetermined size. In the simplest implementation, FM screening is used up to a tone level where the FM dither pattern holes begin to become visible. At this point AM screening is applied only to the remaining dot centers (corresponding to those holes) until they reach the stable dot size. Then, the dots are further grown according to the method used outside of the FM regime (e.g. the conventional AM process). In the FM regime, two types of visual disturbances can arise.

Abstract: A method, associated software and resulting printing plate having both solid and halftone areas comprising ink cells. Ink cells may be provided in the solid areas according to a first pattern with a first density and size of cells per unit area, and in the halftone areas superposed on selected numbers of halftone dots. The selection of halftone dots with superposed ink cells may be according to a second pattern with a second density and size of cells in the halftone area that is a function of halftone dot size and that may or may not be related to the first pattern.

Abstract: Halftone processing section carries out a halftone processing using a dither threshold plane on which thresholds in a predetermined threshold range corresponding to the tone range of input image data are arranged, and provides halftone-processed image data. Image output section has intrinsic, basic tone characteristics and outputs an image corresponding to the halftone-processed image data provided from the halftone processing section. The dither threshold plane consists of a plurality of same unit threshold matrixes and each of the unit threshold matrix consists of a plurality of sub-matrixes. An array of relatively low thresholds in the predetermined threshold range is equal among the plural sub-matrixes, and relatively medium thresholds and high thresholds in the predetermined threshold range are arranged periodically to extend over series of sub-matrixes.

Abstract: A method for converting an original halftone bitmap image to a color converted halftone bitmap image by morphological filtering of the original image to compensate for tone and color reproduction characteristics comprising: providing an original halftone bitmap image. The method includes providing a set of asymmetrical morphological filters that have the property that when they are applied recursively in order, the features in the halftone bitmap image are dilated or eroded by varying amounts by extending or reducing the edges first in one direction, then in two directions, etc.

Abstract: A method for color correcting an original halftone bitmap image by a predefined color correction function to produce a color corrected halftone bitmap image comprising: providing an original halftone bitmap image; estimating the dot area percentage of the original halftone bitmap image in a set of sub-image blocks; calculating an aim dot area percentage, based on a predefined color correction function, for each sub-image block in the original halftone bitmap image, calculating the number of halftone bitmap image pixels to convert to on or off states to produce a modified original halftone bitmap image that has the aim dot area percentage where said value is designated by N, for each sub-image block in the original halftone bitmap image, and converting N pixels in the original halftone bitmap image to either on or off states depending on whether the aim dot area percentage is greater or less than the dot area percentage of the original halftone bitmap image respectively, for each sub-image block in the origina

Abstract: A stochastic halftone pattern has been invented which has a narrow band power spectrum due to the incorporation of a dot growth process. The narrow band power spectrum may be matched to the resolution characteristics of specific printers, resulting in smoother printed halftone textures. The spectrum of a halftone pattern may be made anisotropic (angularly dependent), helping to de-couple sets of patterns for color printing with reduced color noise or mottle.

Abstract: A fluid ejector includes a drop size symbol that is based on the fluid ejector's drop size relative to one or more fixed drop sizes. The drop size symbol is formed by comparing the fluid ejector's drop size to the one or more fixed drop sizes. An image forming device includes a marking fluid ejector that includes a drop size symbol based on the marking fluid ejector's drop size relative to one or more fixed drop sizes. The image forming device forms an image based on the drop size symbol by determining the drop size symbol and then either selecting a marking fluid look-up table based on the drop size symbol, or forming an image correction factor based on the drop size symbol.

Abstract: The invention relates to a method for applying colors by subdividing the colors according to percentages allocated to each of the printing points which are, for example, divided centesimally in accordance with a rule which defines the distribution of appropriately superimposed basic colors, thereby creating binaries and blacks according to the subtraction of the percentage of the basic color most used percentually from the sum of basic colors less used percentually. Thus, the totality of visible colors are optically generated. The background of the surface to be printed is previously analyzed and the percentage quantity in each point of the based colors is deducted in the proportion contained in the background. The application of pigments is carried out by addition of transparent substrate or medium or while, until the proportion of each color is completed.

Abstract: A system and method are provided for linearizing the tone scale of individual colors in a multi-color printing system, by deriving a prescribed tone scale of individual colors in a single or multi-color printing system. Full linear ink gradations are printed on multiple substrates, and a linearization table is generated with multiple points for each of the multiple substrates and/or ink gradations. A polynomial curve is fitted to the points of each linearization table to generate polynomial curves. At least one point in the polynomial curves is selected, that shows high variation from one curve to a next curve, and coefficients of a group of polynomial curves are plotted as functions of the value of the at least one point. The range of prediction can be as narrow or as broad as an application requires. Finally, a prescribed tone scale table is derived from the polynomial curves and the at least one point.

Abstract: An image processing apparatus includes an edge detecting unit which identifies an area of given image data as a gradation sequence area and a character/line art area and which outputs edge information of the character/line art, a level converting unit which generates a strength modulation signal so as to emphasize an edge of the character/line art area, a laser driver which outputs a laser drive signal in order to form a picture dot larger than a standard size in response to the strength modulation signal. Further, according to the present invention, it is possible to print an image with emphasizing an edge portion of a character/line art by a laser printer.

Abstract: An AM half-tone screening process having special utility with a flexographic printing process is described. Such printing processes typically include a desktop publishing unit, a raster image processor for forming half-tone separations, and an image sitter for producing the half-tone separations. In accordance with the invention, the image area is divided into a multiplicity of groups of equally spaced dots. The combined value of the dots in a single group is set at a desired target film value but the individual dots vary in size for film values below a selected transition level. The minimum value of one of the dots can be determined by the operator of the system and, for example, may be greater than the size of the anilox cells in the printing process so that emersion of the raised area into the cell is not possible. The remaining dots of the group decrease in size in proportion to the target film value at a faster rate than the first dot.

Abstract: An image printing method, wherein one pixel is formed from a plurality of dots arranged in a primary scanning direction, in which printing elements are arranged, and in a secondary scanning direction perpendicular to the primary scanning direction; wherein the tone of one pixel is expressed by changing the overall printing area in accordance with whether or not the dots are printed; and wherein a multicolor image is printed by combination of one yellow pixel, one magenta pixel, one cyan pixel, and one black pixel, the method comprising the step of: setting to a nonintegral multiple a dimensional ratio among one yellow pixel, one magenta pixel, one cyan pixel, and one black pixel in the secondary scanning direction.