Abstract: An image processing apparatus is provided, the image processing apparatus including: an interpreting section that interprets instructions of a print control contained in print information, the instructions including a resolution instruction, a monochrome designation instruction indicating whether a monochrome designation is applied, and a page description language designation instruction; a selecting section that selects a binary-processing threshold matrix in response to at least the resolution instruction, the monochrome designation instruction, and the page description language designation instruction by any of ways including selecting and eliminating; and a binary-processing section that binary-processes a page description language contained in the print information by employing the binary-processing threshold matrix selected by the selecting section.

Abstract: An image processing system utilizes an image type classification circuit to identify inputted image data as picture image data or text/graphics image data. A halftone circuit, operatively connected to the image type classification circuit, converts the inputted image data, identified as picture image data, to halftone image data. Moreover, a tile pattern circuit, operatively connected to the image type classification circuit, to replace the inputted image data, identified as text/graphics image data, with tile patterns. Non-halftone cluster areas in the tile patterns are encoded with a predetermined pattern. A bitmap rendering circuit combines the halftone image data with the encoded tile patterns to render a bitmap, wherein the bitmap can be used by a print engine to reproduce the image.

Abstract: A method for creating an image to be printed is provided. A first halftone pattern and a second halftone pattern for respective first and second periodic clustered dot halftone regions of the image are selected. The regions have respective frequencies and one of the frequencies is higher than the other frequency. A transition region is determined. The transition region includes a boundary between the two regions and includes additional portions of the two regions beyond the boundary. The two halftone patterns are blended with each other in the transition region based on a blending ratio of the two halftones where the blending ratio changes as a function of distance between the edges of the transition region.

Abstract: A method for controlling an image processing apparatus includes obtaining image data from a detachable memory unit, estimating whether the obtained image data is image data read by a scanner, and in a case where it is estimated that the obtained image data is image data read by the scanner, performing control not to execute predetermined screen processing on the image data.

Abstract: An image data processing system includes an image input module, a bit map generation module and an encoding module. The image input module receives an image and secret information and obtains at least one gray-level image according to image. The bit map generation module generates a bit map image according to gray-level image and generates an ordered dithering block truncation coding (ODBTC) image according to bit map image and gray-level image. The encoding module generates an encoded gray-level image according to bit map image and secret information, wherein the encoding module divides gray-level image into image blocks, finds candidate blocks with close black and white pixel numbers among the image blocks, selects high frequency blocks belong to the high frequency region of the image from candidate blocks, and randomly embeds secret information into high frequency blocks to generate encoded gray-level image with secret information embedded therein.

Abstract: The present invention relates to a method and apparatus capable of generating frequency-modulation halftone dots in high speed and belongs to the field of the digital image halftone. In the prior art, read-write operation is usually carried out many times in error rows during processing each pixel so that halftone dots are generated in low speed. In the method according to the present invention, the error generated by the current pixel is buffered in a register file and the final accumulated error values are written in the error rows only after all of the relative pixels are processed. Thus, read-write operation is carried out only once in the error rows for processing each pixel. The present invention also provides an apparatus to implement the method. The apparatus comprises an error row memory, an error buffer register file, a gray generation circuit, a threshold comparison circuit, an error generation circuit, an error buffer register file control circuit, and an error row control circuit.

Abstract: Systems and methods of halftoning an image for extended-colorant printing image spot colors are provided which perform a quality ranking of a plurality of periodic halftone screens to be used in halftoning the image and an objectionability ranking of the colorants used to produce the one or more image spot colors. Halftone screen-to-colorant assignments are then made using a ranked ordered pairing of the ranked screens and ranked colorants. The image is halftoned using these assignments and the results can be printed or saved for future printing. Pixel tags can be used to identify the ranked ordered halftone screen-to-colorant assignments.

Abstract: A disclosed method for setting multiple tones in a halftone process upon recording an image using ink includes the steps of: dividing the image into plural dot areas; and setting the multiple tones such that at least one dot area to which the ink is not attached is present between dot areas to which the ink is attached.

Abstract: Methods and systems herein provide for calibrating for a plurality of different paper types. In one embodiment, a system for calibrating a printer includes a measurement module operable to detect colors printed on a first tangible medium by the printer and convert the detected colors to a detected color characterization. The system also includes a storage module operable to store a calibration file. The calibration file includes color characterizations of a plurality of different tangible mediums and each color characterization includes color measurements for one of the plurality of different tangible mediums obtained from the printer via the measurement module when the printer is calibrated. The system also includes a calibration module operable to compare the detected color characterization to at least two color characterizations of the calibration file and determine an adjustment to an output color scheme of the printer based on the comparison to calibrate the printer.

Abstract: An image display device includes: an acceptance unit that accepts image information including at least one character image as a processing object; a detection unit that detects a size of a character included in the accepted image information; an extraction unit that extracts at least one part of the image information as a display object image; a decision unit that decides an enlargement ratio or a reduction ratio based on a size of the character included in the extracted display object image, information on the size of the character detected by the detection unit, and information on a size range for the character; and a display unit that displays the extracted display object image enlarged or reduced at the enlargement ratio or the reduction ratio decided by the decision unit.

Abstract: The image forming apparatus includes a halftone processing section that executes halftone processing having a halftone processing period, a signal add-on section that adds the add-on signals on the input image signals subjected to the halftone processing, a position information acquisition section that acquires position information to determine a relative position of halftone dots by the halftone processing and the add-on signals in a first image area, the first image area is based on a common multiple of the halftone processing period and a minimum interval of the add-on dots, and the position information preventing the add-on signals added by the signal add-on section from crossing over the halftone dots, and an add-on control section that continues or repeats add-on control processing of the add-on signals, executed based on the acquired position information, in a second image area based on the common multiple and consecutive from the first image area.

Abstract: Methods and systems herein provide for halftoning of Run length (RL) encoded datastreams. In one embodiment, a print controller identifies a packet within a RL encoded datastream. The packing includes a header and a block of continuous tone data. The print controller identifies an array of conversion values for converting RL encoded data to halftone data, and indexes the array using one or more bytes of the block of bitmap data. The print controller then outputs halftone data from the conversion array based on the index to convert the RL encoded continuous tone data of the packet to halftone data for a print engine.

Abstract: Disclosed herein is an image processing apparatus including: a screen processor for determining each pixel value of a screen processing application unit region composed of a plurality of pixels to which a threshold matrix is applied, in an inputted image; and for carrying out a screen processing by applying one threshold matrix among a plurality of threshold matrices in which applied positions of the threshold values are different from each other, to the plurality of pixels in the screen processing application unit region based on each determined pixel value.

Abstract: The present disclosure relates to a printed multi-tonal document with enhanced copy evident distortions security features and a method of printing such document. The document may include a multi-tonal background screen image area including a first set of halftone elements and a multi-tonal foreground hidden warning text and/or graphic screen image area including a second set of halftone elements, wherein the first set of halftone elements may be smaller in size than the second set of halftone elements. The multi-tonal foreground hidden warning text and/or graphic image area, when electronically copied, may appear different from the background of the copy of the document.

Abstract: As set forth herein, computer-implemented methods and systems facilitate the generation of halftone screens for moiré-free color halftoning. A first fundamental frequency vector and a second fundamental frequency vector of a halftone cell are sheared using a selected shearing value. The shearing value is selected as an offset in a fast scanning or slow scanning direction. The selected shearing value satisfies various moiré-free conditions associated with the identified frequency vectors and is capable of being selected for multiple halftone screens. The halftone screens generated using the sheared frequency vectors are used for moiré-free halftoning.

Abstract: Disclosed are moiré-free color halftoning methods, apparatus and systems to digitally reproduce an original color image. The disclosed embodiments are particularly useful for rendering a color image with a color printing device. According to one exemplary embodiment, an image forming method utilizes three or four rotated hexagonal screens which can include regular shaped hexagon screens or convex tessellated hexagon screens.

Abstract: An image processing apparatus is provided with a halftone frequency determining section for determining a halftone frequency of an input image data including a plurality of color components. The halftone frequency determining section includes: a threshold value setting section for setting a threshold value for a segment block that is consisting of a plurality of pixels, the threshold value being for use in binarization; a threshold value adjusting section for adjusting the threshold value according to input image data in order to remove an influence of an unnecessary color component; a maximum transition number averaging section for averaging maximum transition numbers of the binary data according to the adjusted threshold value in order to obtain a maximum transition number average; and a halftone frequency estimating section for estimating the halftone frequency from the maximum transition number average. With this, it is possible to determine the halftone frequency accurately.

Abstract: A system and methods for modifying the values of halftoned image pixels to replace a defective colorant with at least one non-defective colorant.

Abstract: A method of characterizing an imaging system is described includes printing a color chart having a plurality of predetermined color patches; measuring the color patches to obtain colorimetric data; initializing a Neugebauer model with the Neugebauer solids of said colorimetric data; optimizing the global parameters of the Neugebauer model; optimizing the parameters associated with Demichel terms based on the Neugebauer primary associated with the Demichel term; optimizing parameters that vary with device coordinates; and creating a characterization file for the imaging system.

Abstract: An image processing apparatus includes the following elements. A characteristic value calculator calculates characteristic values of a preset area set around a pixel of interest. A trapping determining unit determines, for each color plane of an N-valued image, on the basis of the calculated characteristic values, whether the pixel of interest is to be subjected to trapping processing. A pixel value calculator sets, for each color plane, a position of a reference pixel in a reference area, and calculates a pixel value for changing the pixel value of the pixel of interest on the basis of a pixel value of each color plane at the position of the reference pixel. A pixel-of-interest value changing unit changes the pixel value of the pixel of interest into the calculated pixel value when the trapping determining unit determines that the pixel of interest is to be subjected to trapping processing.

Abstract: A halftone correction device for an image forming apparatus including an intermediate transfer belt and performing halftone processes includes: a correction unit that performs halftone correction for each of the halftone processes using correction tables corresponding to the halftone processes; a pattern generation unit that generates on the belt halftone patterns based on at least one of the halftone processes; a measurement unit that measures image densities of the generated halftone patterns; an estimation unit that estimates, from the image densities of the halftone patterns, image densities of halftone patterns corresponding to the other ones of the halftone processes, by applying a relational expression as an estimation equation to patches of the halftone patterns having an equal image area ratio; and a table generation unit that generates the correction tables using target values and the image densities of the halftone patterns of the halftone processes.

Abstract: A method and apparatus are provided for compensating for spatial non-uniformities in a printer by deriving a true spatial non-uniformity tone response curve (TRC) that characterizes the printer in terms of color output variation for each addressable pixel location in a spatial range. The “true average” tone response curve is determined for a color channel. A prediction of the true response as a function of the spatial location is derived by printing and scanning a specially designed halftone-independent target of binary patterns. The predicted tone response curve for each color channel and halftone is predicted using a binary printer model, wherein the “predicted tone response curve” provides a model based approximation of the actual response for each addressable pixel location in the spatial range. Also stored is an “average predicted tone response” by averaging the “predicted tone response curve” over the spatial range of the printer.

Abstract: What is disclosed is a novel system and method for determining whether a pixel resides along a two-color edge in a halftoned bi-level bitmap. In one embodiment, a bitmap having a plurality of colored pixels is received. For each pixel in the bitmap, a window of size n×m is defined centered on the current pixel. The window is partitioned into a plurality of regions with each region having an orientation direction with each orientation direction having an associated numeric value. A number of pixels are counted for each of the first and second colors in each of the associated orientation directions. A determination is made as to the respective orientation direction having the maximum and minimum pixel counts for each of the first and second colors. Thereafter, a determination is made whether the pixel resides along a two color edge based upon the max/min counts and each associated orientation direction.

Abstract: A method and apparatus for processing an image are provided that can suppress blur edges at an edge portion of a character so that sharpness and quality of the image can be improved. The apparatus comprises an inside and outside edge discrimination portion for discriminating whether a target pixel to be processed belongs to an inside edge or to an outside edge, a threshold value generating portion for selecting a threshold value from plural threshold values for error diffusion process in accordance with an area discriminated by the inside and outside edge discrimination portion to output the selected threshold value and an error diffusion process portion for performing the error diffusion process for multilevel input data concerning the target pixel by utilizing the threshold value generated by the threshold value generating portion so as to produce output data whose gradation steps are reduced.

Abstract: Systems and methods are described that facilitate generating a ready-to-print binary dual-plane HLC image for output to an HLC device. A print-ready highlight color (HLC) image can be generated without digital front end (DFE) processing. For example, according to one or more aspects, a color scanner can be employed to produce a two-plane binary TIFF image. One plane contains black (e.g., achromatic) content, while the other contains highlight color content. Black pixels are identified and/or determined using neutral pixel and neutral window detection. Background pixels are mapped to white for both planes. Pixels that are non-neutral and non-background are designated as color pixels. After separation into a neutral plane and an HLC plane, the planes are processed into binary data for printing.

Abstract: A printing system is disclosed. The printing system includes an image processor to selectively rasterize a plurality of objects, and to determine if a size of a first object is less than or equal to a predetermined threshold perform a single-cell halftone process on the first object if the size of the first object is less than or equal to the predetermined threshold and perform a super-cell halftone process on the first object if the size of the first object is greater than the predetermined threshold.

Abstract: A 2-pixel averaging unit (101) halves an input image in the subscanning direction, and a multi-level error diffusion unit (102) performs multi-level error diffusion processing. A 2-pixel reconstruction unit (103) replaces each pixel with two pixels adjacent in the subscanning direction. A density value exchange unit (104) exchanges pixel values adjacent in the subscanning direction in each of 2×2 pixel blocks arranged in a checkered pattern in the image after replacement. High-density blocks each serving as a set of high-density dots and low-density blocks each serving as a set of low-density dots can be generated as 2×2 pixel blocks. The exposure region can be concentrated in PWM conversion.

Abstract: Techniques are provided that use one or more templates to improve the printing of non-saturated colored text and lines. Such templates are predetermined, fixed patterns which can be indexed or looked up via a code word with a fewer number of bits than in the corresponding template. Thus, such templates are used to increase the resolution or effective resolution of a display. In an embodiment, each template location represents a 4×4 region of binary pixels. The number of possibilities of template values is 2?(4*4) or 65,536. However, in accordance with an embodiment, only 256 of these 65,536 templates are available and are indexed by an 8 bit contone video value.

Abstract: A method and system modify a rasterized digital image to reduce registration artifacts, the image having a black plane and a color plane by determining if a pixel is part of a connected black region and if the pixel is part of a connected color region. It is determined if the pixel is part of a connected black region and a connected color region that are contiguous. A dilation operation is performed on the color plane value of the pixel if the pixel is part of a connected black region and a connected color region that are contiguous.

Abstract: In a matrix area, a plurality of linear areas each of which extends in a tilt direction tilted relatively to row and column directions are arranged in a direction perpendicular to the tilt direction without spaces, and the plurality of linear areas are alternatively assigned to first and second element groups along an arrangement direction. One element is specified in each element group, and subsequently a process of specifying an element farthest from the specified elements is repeated, to acquire a turn-on order of dots with increase in gray level in one grayscale range and a turn-off order of dots with decrease in gray level in the remaining grayscale range, and a threshold value of each element is determined according to these orders. Thus, generated is a threshold matrix capable of reducing graininess in a halftone image with directionality in the tilt direction, and improving the reproduction of thin lines and characters.

Abstract: A data conversion apparatus which converts data including a K pixel amount of bit data expressed as N bits/1 pixel, where N and K are plural, using conversion data of predetermined bits comprising: a holding unit configured to hold input data in K×N bits; an acquisition unit configured to acquire from the conversion data a number of bit patterns corresponding to a decimal value expressed by N bits among a conversion target to convert the input data held by the holding unit by N-bit units; a storage unit configured to store a pattern of N bits corresponding to a decimal value obtained from a bit pattern acquired by the acquisition unit in a bit position of the conversion target; and an updating unit configured to update the bit position of the conversion target each time the acquisition unit and the storage unit perform processing.

Abstract: An image processing apparatus includes an input unit which inputs a plurality of image object data, an acquisition unit which acquires resolution information and area information, a generation unit which generates image data based on the resolution information and stores the image data in a memory unit, an extraction unit which extracts overlap area information and resolution information of each of the image objects, and a composition unit which reads out, from the memory unit, pixel data corresponding to a pixel position of interest in accordance with the area information, if a plurality of pixel data existing at the pixel position of interest are located in the overlap area, converts one of the plurality of pixel data in accordance with higher resolution information extracted by the extraction unit, composites the converted pixel data with the other pixel data, and outputs the pixel data.

Abstract: An image printing system which determines dot forming condition when printing an image containing a plurality of pixels by using dots of a plurality of sizes includes: a fine drawing detecting unit which detects a dot color fine drawing pixel having a dot color used for printing the image and positioned on a fine drawing portion having a drawing width equal to or smaller than a predetermined value; an edge area detecting unit which detects a dot color edge area pixel having a dot color used for printing the image and positioned at a distance equal to or shorter than a predetermined value from an edge of the image; a first dot allocating unit which allocates dots such that a dot of predetermined size in the dots of the plural sizes can be formed for the dot color fine drawing pixel during printing the image; and a second dot allocating unit which allocates dots such that a dot of a size determined according to the distance from the edge of the image in the dots of the plural sizes can be formed for the dot col

Abstract: When a halftone frequency inputted to a diffusion coefficient storage section is a low halftone frequency, or when the halftone frequency is a middle halftone frequency or high halftone frequency and a zoom level is a middle zoom level or high zoom level, the same set of diffusion coefficients are selected. Moreover, when the halftone frequency inputted to the diffusion coefficient storage section is the middle halftone frequency or high halftone frequency and the zoom level is the low zoom level, individual sets of diffusion coefficients are selected for respective current pixels. A diffusion error calculation section calculates diffusion errors to be diffused to respective not-quantized peripheral pixels of the current pixel, based on a quantization error inputted from a quantization error calculation section and the set of diffusion coefficients selected from the diffusion coefficient storage section.

Abstract: As set forth herein, computer-implemented methods and systems facilitate halftoning by adapting 2nd generation halftone techniques to the spatial frequency content of an image utilizing a spot function introduced in conjunction with a technique for determining seed locations, which results in halftone images exhibiting improved edge and detail rendition. A dominant orientation of pixels in an input image is employed to select a pre-generated stochastic screen used to determine the seed locations.

Abstract: A model-based halftone independent method for characterizing a printer equipped with a plural of halftone screens comprises: printing a target set of basic patches comprised of a fundamental binary pattern independent of a halftone screen; measuring true color printer response from the target set; modeling a halftone independent characterization of the printer with the mathematical transformation using the measured response; modeling a first halftone dependent characterization of the printer with the mathematical transformer to generate a first predicted result using a selected halftone screen; comparing a measured response of the printer using the halftone screen with the predicted result to define a correction factor corresponding to the halftone screen; and modeling a halftone dependent characterization of the printer using a predicted response of the fundamental binary pattern and the correction factor.

Abstract: A method and system are provided for characterizing performance of a printer across a plurality of halftone screens. A first non-uniformity profile is generated by measuring printer performance. Cross-position differences between the first non-uniformity profile and selected corresponding cross-positions of a second halftone screen are detected. A scaling factor is computed relating the detected differences. Printer performance with the second halftone screen is predicted by applying the scaling factor associated with the second halftone screen to the non-uniformity profile of the first halftone screen.

Abstract: In an image processing device, the memory stores conversion characteristic information corresponding to respective recording portions of an image recording device that records an image at a recording medium while moving a recording unit, which is provided with a plurality of the recording portions arrayed in a first direction, relative to the recording medium in a second direction that is perpendicular to the first direction, the conversion characteristic information expressing conversion characteristics for converting image data in units of one pixel. The first processing unit performs conversion processing along the first direction, continuously converting respective sets of pixel data aligned in the second direction, using conversion characteristic information that corresponds to the recording portions. The second processing unit performs image processing in the order of processing by the first processing unit.

Abstract: As set forth herein, computer-implemented methods and systems facilitate halftoning using a parametrically controlled spot function based on triangle tessellation, which in turn facilitates dot growth control of periodic halftone using an irregular seed structure. The spot function determines the shape of the halftone dot used to reproduce a given pixel. The spot function is well suited for growing halftone dots arrayed on a non-regular grid and can also be used for grids with regular order. The spot function includes adjustable parameters for controlling its sharpness and slope.

Abstract: Before image data are screened for the subsequent exposure of a printing form, files needed for the screening step are changed in such a way that the values of individual elements in the data fields are changed. The number of elements whose values are changed is determined by evaluating contiguous regions within the data fields. These can be, for example, threshold value matrices in which individual matrix elements are set to a value corresponding to the color white, or which, for the half-tones, are calibrated to a reduced value of the full-tone density. In the latter case, the full-tone image points are screened with a frequency-modulated screen.

Abstract: A halftoning process includes: receiving CMYK input pixel data in terms of continuous tone input data values for cyan, magenta, yellow, and black colors converting the CMYK input pixel data to modified CMYKRGB* pixel data that define the input pixel in terms of error-adjusted continuous tone data values quantizing the modified CMYKRGB* pixel data to derive intermediate output CMYKRGB pixel data in which the cyan, magenta, yellow, black, red, green, and blue colors are each defined by either a first quantized value that represents no color or a second quantized pixel value that represents full color converting the intermediate output CMYKRGB pixel data to CMYK output data.

Abstract: In a case where a reusable object extracted from a print job and is subjected to transformation processing upon reuse thereof, a print device executes halftone processing taking into account the transformation indicated by the transformation processing for the reusable object, and generates image data to store the generated image data in a cache.

Abstract: A method for using a processor to process image data received from an image data source in preparation for multipass printing, comprising multitoning the image data to produce a multitoned image, using the multitone level of a pixel in the multitoned image to select a plane of a print mask, using the location of the pixel in the multitoned image to select a cell of output pixels in the selected plane of the print mask, and copying the selected cell of output pixels to corresponding locations within a print buffer.

Abstract: A method and system for controlling the darkness level of image data to assist in output matching between dissimilar rendering devices. Image source information from a source file can be interpreted by a rendering decomposer in order to generate halftone source image data. The decomposition of the image can be repeated in response to a request by an operator for an additional darkening level via a user input file. The additional layers can be shifted in an opposing direction and then a clockwise direction from the original position until the additional darkening level is attained. The required darkening level can be stored in a storage unit or memory so that the required darkening level can be later triggered by a source document name to employ the same darkening approach. The darkening level can be selected from an array of darkening levels to assist in output matching without major modifications to the utilized rendering device(s).

Abstract: A method and system modify a rasterized digital image to reduce registration artifacts, the image having a black plane and a color plane by determining if a pixel is part of a connected black region and if the pixel is part of a connected color region. It is determined if the pixel is part of a connected black region and a connected color region that are contiguous. A dilation operation is performed on the color plane value of the pixel if the pixel is part of a connected black region and a connected color region that are contiguous.

Abstract: A printing method for printing an input image. Firstly, a halftone mask is generated. The input image is transformed into a halftone image through the halftone mask. The halftone image is then output for printing. The halftone mask is an array of N elements, and the following steps generate the halftone mask. An initial array of N elements is first provided. Thereafter, a first value is selectively assigned to an element in the initial array to generate a first array. The second to the Nth arrays are then recursively generated based on the first array in the following steps. A minimum energy element in an Ith array is first determined. An (I+1)th value is then assigned to the minimum energy element to generate an (I+1)th array, wherein I denotes 2 to N?1.

Abstract: Even when image processing such as halftone processing and zoom processing is performed, it is enabled to execute image processing at high speed. When controlling image processing which is performed by each of a first image processing portion and a second image processing portion in parallel and independently from each other for image data including a plurality of pages, a control portion performs execution control by selecting any of the first image processing portion and the second image processing portion for each page of the image data and causing the first image processing portion or the second image processing portion which is selected to execute the image processing for the page.

Abstract: A processing condition selecting apparatus, a processing condition selecting method, and a storage medium storing a program therein serve to evaluate the production aptitude of a print under a signal processing condition, based on image forming information with respect to the print and prescribed evaluation criteria, to thereby generate a display image visually representing the production aptitude of the print that has been evaluated.

Abstract: A method for correcting at least one uniformity error selected from the group consisting of a process direction uniformity error and a cross-process direction uniformity error in an image printing system that prints on an image bearing surface movable in a process direction. The method includes printing on a media a test pattern that includes a plurality of segmented regions extending in the direction of the at least one uniformity error being corrected, receiving a correction data from the user, and adjusting a profile of the image printing system to correct for the at least one uniformity error based on the received correction data Each segmented region comprising a coarse halftone area and a fine halftone area adjacent one another. The resolution of the fine halftone area is at least about 1.5 times the resolution of the coarse halftone area.

Abstract: Methods and systems herein provide for reducing artifacts during printing. One printing system is operable to prepare a continuous tone image (CTI) for printing onto a print medium by generating an initial half tone image (HTI) based on the CTI. The printing system includes a printer and a print controller. The print controller filters the initial HTI and the CTI with a perceptual filter and determines an error between the filtered CTI and the filtered HTI. The print controller prints the HTI via the printer to determine printer artifacts and processes a scanned version of the printed HTI to determine an error between the filtered CTI and the scanned and filtered HTI. This processing updates the initial HTI and reduces the error between the filtered CTI and the filtered HTI.