Abstract: A method and system are provided for processing digital multi-colour images for the reproduction thereof on a colour printing and/or copying system. Particularly, the printing and/or copying system is capable of complementary forming registered composite multi-colour images of coloured marking particles. This means that the separation images of coloured marking particles are formed contiguous to each other rather than in a superimposed relationship. The digital multi-colour images are processed such that during reproduction thereof any adverse effects on image quality caused by register errors in a predetermined direction are eliminated or at least limited. To accomplish this, a particular halftoning technique is used wherein with gradually increasing input density value of the image pixels, a linear growth pattern is generated in the predetermined direction by alternately adding image dots to both sides.

Abstract: In an apparatus for performing printing using a color ink-jet head having a plurality of ink-discharge-port strings corresponding to ink materials having different color tones, a high-quality image having excellent gradation can be recorded, while reducing the cost of the apparatus and increasing the data processing speed by reducing the capacity of a memory for storing dot arrangement patterns.

Abstract: A combined profile is created through a first step of deriving a coordinate component of a black on a color space for CMYK dot % for a printer associated with a predetermined representative coordinate in the color space for CMYK dot % for printing, on the representative coordinate, based on a printing profile and a printer profile; a second step of deriving a coordinate component of the black on the color space for CMYK dot % for a printer associated with coordinates other than the representative coordinate, based on the coordinate component of the black associated with the representative coordinate; and a step of deriving coordinate components of cyan, magenta and yellow on the color space for CMYK dot % for a printer, on the coordinates corresponding to the coordinate components derived in the first and second steps, based on the derived coordinate components of the black, the first and second color conversion definitions.

Abstract: An image region discrimination section in an image processing section, a characteristic signal calculation result obtained by hardware is subjected to macro-scoped correction and macro-discrimination by a processor. Further, in the image region discrimination section, a resolution and a signal bit number of a characteristic signals are decreased, the resultant characteristic signals is stored in a memory, and both a macro-discrimination result and the characteristic signals are synthesized to produce a final discrimination signal.

Abstract: Systems and methods of processing scanned pages are described. In one aspect, the invention features a method of processing a sequence of scanned pages of a document in accordance with which, page number indicators are extracted from scanned pages of the document. A histogram of extracted page number indicators is computed. Scanned page sequence information is determined based at least in part on the computed histogram. A computer program and a system for implementing the scanned page processing method also are described.

Abstract: An image processing apparatus includes an edge amount calculating device configured to calculate edge amounts of an image in a plurality of directions for each of a plurality of frequency bands of the image. A character edge area determination device determines, based on the calculated edge amounts, whether or not a selected picture element of the image is of a character edge area. A sharpness control device corrects a frequency characteristic of the image by performing a first correction to the edge amounts when the selected picture element is determined to be of a character edge area by the character edge area determining device, and by performing a second correction to the edge amounts when the selected picture element is determined not to be of a character edge area by the character edge area determining device.

Abstract: An image processing device for processing an input image so as to reproduce a halftone, includes: a matrix setting section for setting a threshold matrix having a plurality of elements arranged in M columns×N rows, at least two threshold values being stored in each of the elements; an element specifying section for specifying a corresponding element of the threshold matrix in accordance with a position of a pixel in the input image; and a multilevel signal generating section for fetching the threshold values from the specified element and for generating a multilevel signal by transforming an input pixel value to one of multiple levels in accordance with the fetched threshold values; wherein the multilevel signal generating section outputs a constant value Doutmin as the multilevel signal when a first condition that the input pixel value is smaller than or not larger than a minimum value of the threshold values, is satisfied; the multilevel signal generating section outputs a constant value Doutmax when a seco

Abstract: A method for determining lattice points to be referenced to prepare the correspondence defining data, said method including steps of prescribing a smoothness evaluation function which has a function form differing depending on each region in the color gamut to which the lattice point to be evaluated belongs and also contains a constraint condition that the closer the lattice point is to the boundary of the region of the color gamut, the more the evaluated value decreases as the result of its movement, optimizing the arrangement of lattice points in the device-independent color space by improving the rating of the smoothness evaluation function, with the lattice point position information in the low-dimensional color space varied, and determining lattice points to be referenced to prepare the correspondence defining data in the optimized state.

Abstract: The amount of moiré in halftone printed images is reduced using unique moiré intensity functions and moiré vectors in a halftoner. In various embodiments, moiré phase angle zones are determined over the full field of an image and high addressability units in the full-field moiré phase angle zones of the image are adjusted, including in an iterative manner, until they significantly reduce the moiré. A useful relationship between halftoner memory locations and moiré phase angle zones in a full field image is determined. The moiré that occurs in a halftone image is quantified and moiré compensation values obtained are then used to generate an inverse moire amount which is used to compensate for the moiré.

Abstract: A method for eliminating moire in scanned digital image comprises the steps of using an average circuit for taking weighted average and error diffusing a gray level difference between an error diffusion pixel Gij and neighbor pixels to neighbor to obtain output image pixel Y?ij; using a second adder for subtracting the error diffusion pixel Gij from the output image pixel Y?ij to obtain a neighbor image error dij; using a error filter H(z) to process the neighbor image error dij to obtain a corrected pixel error H(d(i,j)); and using a first adder for adding the corrected pixel error H(d(i,j)) and the input image pixel Yij to obtain the corrected error diffusion pixel Gij, and then jumping to first step until all pixels being processed. The method provides real time treatment for eliminating moire and provide smooth image.

Abstract: The invention relates to an apparatus for printing a multibit per pixel image (10) from a halftone binary digital bitmap having pixels having a multibit per pixel image memory for receiving the multibit per pixel image; a lookup table (16) external to the memory disposed in a programmable gate array (18) for converting the multibit per pixel image to a base duty cycle (20) wherein the base duty cycle is disposed in the programmable gate array and is adapted for creating a modulated drive signal (22) from the base duty cycle to modulate an exposure (24) for each pixel in the multibit per pixel image; and a printer (28) adapted for using the modulated exposure to print an image, having a dpi greater than 1400, further comprising a drum (32) capable of spinning, and an encoder (34) disposed on the drum for providing a home signal (36) and a pixel rate (38).

Abstract: Four test patterns are concurrently displayed on a display of a computer. The test patterns include respective backgrounds and contrast areas. The test patterns, different from each other in pixel value, have identically shaped contrast areas. The contrast between the background and the contrast area remains unchanged from test pattern to test pattern. The contrast areas are adjusted in contrast with the pixel value of the background fixed until the test patterns look the same.

Abstract: Dynamic Color Render Dictionaries are provided to automatically switch color rendering behavior between object types. The implementation resides entirely within the Color Render Dictionary (CRD) and require no changes to the state of the Postscript interpreter (There are no required “C” code changes and Postscript operator redefinitions.) The different color rendering behaviors are accomplished by concatenating multiple color transform tables into a single/RenderTable within the CRD. The different rendering behaviors are accessible to single graphics state by simply accessing different regions of the /RenderTable. By having the color rendering behavior “switch” without changing the graphic state makes the implementation very fast. Since the entire implementation is limited to the Color Rendering Dictionary, dynamic CRDs may be implemented on any existing Postscript printer. Even on ones that have been in the field for years.