Abstract: This disclosure provides a method and system to generate device dependent color space representations for an image output device. The method and system are particularly applicable to a printing device, where gamut boundary separated profile methods are executed to map device in-gamut and device out-of-gamut colors.

Abstract: A multi-dimensional printer profile look-up table for color correction is generated. First, an initial estimate for a black (K) component in a four-color color space for received color signals in the device independent color space is generated by using a three-dimensional parametric function. Next, initial estimates for the three non-black color components of the four-color color space are generated from the generated initial estimate for the black (K) component and the received color signals. Then, a printer profile including a map that maps the device independent color space to the four-color color space is generated using the generated initial estimates for the black (K) and the three non-black color components in the four-color color space.

Abstract: A method for encryption of a digital watermark by intelligent halftoning includes receiving image data that define at least a portion of a document to be printed in terms of at least three halftone images corresponding respectively to three printing colorants, each of the three halftone images comprising a plurality of halftone cells. The image data are modified by phase-shifting some of the halftone cells of at least one of the halftone images relative to the other halftone images to encode a watermark within the portion of the document such that the at least one phase-shifted halftone image includes a phase-shifted region and a non-phase-shifted region. The modified image data are used to print the portion of the document on a substrate that will fluoresce when subjected to UV illumination. The printed portion of the document includes a first printed pattern resulting from the phase-shifted region and a second printed pattern resulting from the non-phase-shifted region.

Abstract: A fluorescence-based correlation mark is included in a printed document by encoding the correlation mark as phase shifts in the yellow halftone image only of a printed color document. The correlation mark transparency key is likewise printed using only yellow colorant or can be printed in black or with another colorant or mixture of colorants that will appear dark or black when subjected to UV illumination. UV illumination of the document without use of the transparency key, and use of the transparency key without UV illumination of the document are insufficient to reveal the fluorescence-based correlation mark. UV illumination of the document while the transparency key is overlaid with the document will allow the correlation mark to be perceived.

Abstract: Systems and methods preserve the information lost in gamut-mapping during marking (e.g., printing) such that the lost information survives the marking and recapture (e.g. scanning) process. Generally, an encoding method may include gamut-mapping and image for a particular device; determining a residual image; and embedding the information needed to recover the residual image within the pixels of the gamut-mapped image. Generally, a decoding method may include extracting the embedded information from the image; and using the residual image to restore the gamut-mapped image to the original image.

Abstract: The proposed systems and methods automatically select the node locations of a multi-dimensional lookup table transformation in accordance with the relative importance of multi-dimensional input values. Such importance, as an example could be quantified by the statistical distribution of the input data. Additionally, the proposed scheme is efficient and works for inputs of arbitrary dimensionality. Finally, the proposed method accounts the characteristics of the input-data and the geometry of the input space. The proposed systems and methods are generally applicable to a large number of practical scenarios including, but not limited to, color imaging applications where input adaptive color look-up tables are desired.

Abstract: One aspect of the disclosure is directed to a calibration system. The calibration system includes a given imaging device including a predetermined print engine capable of being calibrated and a calibration sheet. The calibration sheet includes at least one visible calibration reference region including a given mix of one or more pre-selected reference colorants printed in the at least one calibration reference region on the calibration sheet. The one or more pre-selected reference colorants have been previously printed on the printable calibration sheet using a different imaging device that is different than the given imaging device and that has the same print engine as the given imaging device. The calibration sheet includes one or more freshly printable target regions on the calibration sheet.

Abstract: Spatially dependent colorant interaction effects are identified and isolated from other aspects of spatially dependent colorant appearance nonuniformities. A decorrelating function for compensating for the identified spatially dependent colorant interaction effects is determined. Spatially dependent single colorant compensating functions for compensating for the other aspects of the spatially dependent colorant appearance nonuniformities may also be determined. Image data is processed through the decorrelating function, thereby generating colorant values that are compensated for spatially dependent colorant interaction effects. Optionally, image data is also processed through the spatially dependent single colorant compensating functions, thereby generating colorant values that are compensated for both aspects of colorant appearance nonuniformities. The two kinds of compensating functions may be determined, calibrated and/or stored at different spatial and temporal frequencies or resolutions.

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. In a one-time offline process, the “true average” tone response curve is determined for a color channel and stored. The “true average” tone response curve defines an average true response for the printer across the printed output spatial range. 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 and stored, wherein the “predicted tone response curve” provides a model based approximation of the actual response for the printer for each addressable pixel location in the spatial range.

Abstract: A computer program product and method for calibrating and characterizing a color display perform calibrating and characterizing steps. A light source is operated in order to emit light from one or more light emitters on the light source. A color capture device, e.g., a digital camera, is calibrated and characterized based on the emitted light. Then, color images are displayed on the color display and captured on the color capture device. The color display is calibrated and characterized based on the captured color images. Computer program instructions are recorded on the computer readable medium, and are executable by a processor, for performing the calibrating and characterizing steps. A method for generating a controlled light source includes displaying light source selections to a user and receiving a user light source selection. Selected light emitters produce a light output matching the user light source selection.

Abstract: The teachings as provided herein relate to a watermark embedded in an image that has the property of being relatively indecipherable under normal light, and yet decipherable under infrared illumination when viewed by a suitable infrared sensitive device. This infrared mark entails in combination with at least one distraction pattern, a substrate reflective to infrared radiation, and a first colorant mixture and second colorant mixture printed as an image upon the substrate. The first colorant mixture layer in connection with the substrate has a property of strongly reflecting infrared illumination, as well as a property of low contrast under normal illumination against a second colorant mixture as printed in close spatial proximity to the first colorant mixture pattern, such that the resultant image rendered substrate suitably exposed to an infrared illumination, will yield a discernable image evident as a infrared mark to a suitable infrared sensitive device.

Abstract: The teachings as provided herein relate to a watermark embedded in an image that has the property of being relatively indecipherable under normal light, and yet decipherable under infrared illumination when viewed by a suitable infrared sensitive device. This infrared mark entails, a substrate reflective to infrared radiation, and a first colorant mixture and second colorant mixture printed as an image upon the substrate. The first colorant mixture layer in connection with the substrate has a property of strongly reflecting infrared illumination, as well as a property of low contrast under normal illumination against a second colorant mixture as printed in close spatial proximity to the first colorant mixture pattern, such that the resultant image rendered substrate suitably exposed to an infrared illumination, will yield a discernable image evident as a infrared mark to a suitable infrared sensitive device.

Abstract: The teachings as provided herein relate to a watermark embedded in an image that has the property of being relatively indecipherable under normal light by including a distraction pattern, and yet remains decipherable under infrared illumination when viewed by a suitable infrared sensitive instrument. This infrared mark comprises, a substrate reflective to infrared radiation, a foreground colorant mixture printed as an image upon the substrate, a background colorant mixture and a distraction colorant mixture. The foreground colorant mixture layer in connection with the substrate has a property of strongly reflecting infrared illumination, as well as a property of low contrast under normal illumination against the background colorant mixture as printed in close spatial proximity to the foreground colorant mixture pattern.

Abstract: The teachings as provided herein relate to a watermark embedded in an image, and methodology for same, that has the property of being relatively indecipherable under normal light, and yet decipherable under UV light. This fluorescent mark comprises a substrate containing optical brightening agents, and a first dot design printed as an image upon the substrate. The first dot design has as a characteristic, the property of strongly suppressing substrate fluorescence. A second dot design having a property of providing a differing level of substrate fluorescence suppression from that of the first dot design such that when rendered in close spatial proximity with the first dot design image print, the resultant image rendered substrate suitably exposed to an ultra-violet light source, will yield a discernable image evident as a fluorescent mark.

Abstract: The teachings as provided herein relate to a watermark embedded in an image that has the property of being relatively indecipherable under normal light, and yet decipherable under UV light. This fluorescent mark comprises a substrate containing optical brightening agents, and a first dot design printed as an image upon the substrate. The first dot design has as a characteristic the property of strongly suppressing substrate fluorescence. A second dot design having a property of providing a differing level of substrate fluorescence suppression from that of the first dot design such that when rendered in close spatial proximity with the first dot design image print, the resultant image rendered substrate suitably exposed to an ultra-violet light source, will yield a discernable image evident as a fluorescent mark.

Abstract: A calibration system includes a printer capable of being calibrated and a printable calibration sheet. The printable calibration sheet includes at least one calibration reference segment printed on the sheet and one or more defined printing spaces on the sheet. The at least one calibration reference segment includes one or more pre-selected colorants on the printable sheet. The one or more defined printing spaces are adjacent to the at least one calibration reference segment. The one or more defined printing spaces are arranged to accept printing of a color pattern from a printer under calibration.

Abstract: Methods and systems are presented for calibrating or characterizing a color printer or determining the color response of a color printer to combat spatial non-uniformity, in which color patches are printed on a test page according to an input matrix of input color in a printer-dependent-color space and the test page is measured to provide a corresponding output matrix of output color in a printer-independent-color space. Initial forward and inverse color transforms between the input and the output colors are generated based on the input and the output matrices. The output values are mapped to the input color space based on the initial inverse transform to form a feedback matrix, and spatial non-uniformities present in the printed test page are estimated according to noise values derived from the input matrix and the feedback matrix.

Abstract: A device calibration method based on two-dimensional calibration transform that allows complete control of two-dimensional planes in the three-dimensional CMY (Cyan, Magenta, and Yellow) cube. Two-dimensional planes can be identified in the three-dimensional CMY cube as a primary plane and projected onto two-dimensional calibration lookup tables (LUTs) for C, M, and Y. The LUTs are filled with CMY colorant values that will maintain a fixed color (e.g. CIELAB) response within the chosen primary planes. There are three possible realizations depending upon which primary diagonal CMY plane is chosen. This technique can be used to calibrate an engine over time and to bring two or more engines to the same desired state.

Abstract: A multifunctional device that processes electronic data includes a processor that processes the electronic data, a memory that stores the electronic data, an alteration circuit that alters the structure of the electronic data and a controller that determines whether idle time exists when the electronic data is stored in the memory, and controls the alteration circuit to alter the electronic data when the controller determines that idle time exists. Moreover, a method of processing electronic data includes processing the electronic data, storing the electronic data, controlling the electronic data by determining whether idle time exists when the electronic data is stored and altering the electronic data when sufficient idle time exists.

Abstract: A method is provided for creation of a substrate fluorescence mask having background color(s), UV mark color(s), and distraction color(s), to be printed as an image on a substrate containing optical brightening agents. The method includes selecting one or more UV mark colors for the mask such that the UV mark colors exhibit low contrast against the background color(s) under normal illumination and high contrast against the background color(s) under UV illumination. One or more distraction colors are also selected, such that the distraction color(s) exhibit low contrast against the background color(s) under UV illumination and exhibit high contrast against the background color(s) under normal illumination. A distraction pattern, formed from one or more distraction colors, is also selected.