Abstract: Disclosed are systems and methods for halftone independent temporal color drift correction, particularly for correction in hi-addressability xerographic printers

Abstract: What is disclosed is a system and method for searching a repository of documents containing images using an image as a query. The present method enables the adjustment of a threshold level through a no-reference quality assessment of the query image which produces an estimated measure of quality for the image. For each image in each document in the repository, a distance is computed between a hash value of each image extracted from the document and the hash value of the query image. Documents are flagged as possible matches if the computed distance is less than the adjusted threshold. Documents flagged as a result of the search are retrieved and provided to the user. The present method can be used along or as an adjunct to text-based search techniques. Other embodiments are provided.

Abstract: A model-based method and apparatus for characterizing the performance of a printing device comprising printing a target set of patches with the device and measuring device response when the target is set; compiling a LUT from the target set and measured response; and representing the LUT as a tensor. Tensor decomposition/parallel factor analysis is employed for compacting the tensor representation of the LUT.

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 for optimizing network transmission of print documents to a rendering device. A document for rendering (e.g., print job) can be received and metadata related to the document analyzed simultaneously. The metadata can then be compared to a number of locally saved files and the document containing matching metadata can be rendered directly from a local storage device, thereby reducing network traffic. Otherwise, the document can be transferred over a network to the rendering device. A record of a number of times the document is being requested for rendering can be tracked by the rendering device in order to retain the document for an extended period of time.

Abstract: What is disclosed is a method for iterative seam selection in an image resizing system utilizing a seam carving technique. In one embodiment, an importance map is generated for a received source image. Seams are carved through the image from one edge to an opposite edge. An energy is computed for each seam based on pixel importance values. A distance is computed from each seam to a previously selected seam. A weighting for each seam is computed using a defined weighting function and the calculated seam distances. The weighting is applied to the energy of each seam produce a revised energy for each seam. A seam is selected based on the produced revised energy. The image is resized at a location of the selected seam. The process repeats until the image has been resized to a desired target output dimension. In such a manner, unnatural image resizing results are avoided.

Abstract: A method for compensating for color drift in a printer includes determining a first true tone response curve for a color channel when said printer is in a first state. A first estimated tone response curve for the color channel is also determined when said printer is in the first state. A second estimated tone response curve for the color channel is determined when the printer is in a second, color-drifted state relative to the first state. A second true tone response curve for the color channel is mathematically predicted using the first true tone response curve, the first estimated tone response curve, and the second estimated tone response curve. The first and second estimated tone response curves are estimated using a 2×2 printer model. A printing apparatus includes an image processing unit for implementing the color-drift correction process.

Abstract: What is provided is a system and method for node set construction and look-up table generation to transform image data in the form of color values of an input color image in an input color space to an output color space of an image output system. In the present method, node locations are selected based upon an importance value generated by a significance function which describes a relative importance of a given color value in the input image or a region thereof. A distance weighting function is also provided which is applied to the significance function to balance the significance of a given node against a relative positioning of all other nodes in the multi-dimensional grid. Nodes can be added or deleted according to methods also described herein. Accordingly, a multi-dimensional look-up table is generated wherein node tiling is based upon a significance of color values of an input image.

Abstract: Disclosed are systems and methods for color calibration incorporating gray-component replacement, and more particularly, controlling gray component replacement in a color output device by applying a pre-defined transformation to a plurality of non-black channels to obtain at least one intermediate variable, and determining at least one output black (K) value from both the black channel input value and the intermediate variable, in order to provide control of gray component replacement in the color output device.

Abstract: What is disclosed is a novel system and method for encoding/decoding data in a cover contone image via halftone dot orientation modulation. Arrays of halftone threshold values are used to determine a desired orientation, e.g. 0/90°±45° for a given single data value of the original message to be embedded. Message data is embedded as a function of halftone dot orientation. Detection modeling of the print-scan process enables the determination of dot orientation from the image scan via statistically motivated image moments. A probabilistic model of the print-scan channel conditions received moments on input orientation. Density values of the received moments are used to determine dot orientation for each halftone cell. The embedded data is retrieved based on the determined orientations. The present method is applicable to areas of data embedding, document security, and the like.

Abstract: What is disclosed is a novel system and method for encoding/decoding data in a cover contone image via halftone dot orientation modulation. Arrays of halftone threshold values are used to determine a desired orientation, e.g. 0/90°+/?45° for a given single data value of the original message to be embedded. Message data is embedded as a function of halftone dot orientation. Detection modeling of the print-scan process enables the determination of dot orientation from the image scan via statistically motivated image moments. A probabilistic model of the print-scan channel conditions received moments on input orientation. Density values of the received moments are used to determine dot orientation for each halftone cell. The embedded data is retrieved based on the determined orientations. The present method is applicable to areas of data embedding, document security, and the like.

Abstract: What is disclosed is a novel system and method for content-aware resizing of a digital image. To take advantage of the characteristics of various importance maps generated for the image using different operators such as, for example, gradient, entropy, probabilistic operators, and the like, a method is provided herein for combining generated pixel importance maps. The present method uses a weighted combination of pixel importance maps—one corresponding to each image operator, to produce a hybrid map for all the image. The image can then be resized based on this hybrid map. The present method provides a high degree of image resizing flexibility and has broad applicability across differing classes of images and applications such as display, printing, packaging, and other document image processing software performing document layout, image personalization, and the like.

Abstract: In accordance with the disclosure, a method is provided for processing color images for rendering on a color image. The method comprises receiving a plurality of device color separations for an image intended for rendering on a color image device; forming at least one intermediate image by interleaving pixels from at least two of the device color separations, compressing the at least one intermediate image in a compression module; decompressing the at least one intermediate image in a decompression module; processing the at least one decompressed intermediate image through a multidimensional calibration transform to output a calibrated device color separation; and, the device color separations include at least three colors.

Abstract: A method and system for identifying print jobs that are repeats of a previously completed job utilizing an object level hash table. Received print jobs can be parsed into meaningful classes of objects and a table of hash values can be computed for objects in each class and for each print job. A synopsis comprising the table of hash values can be retained in a database along with the job specific settings. A newly encountered job can be then declared as a repeat of a previous job based on the hashes for the new job that match the hash values for the previous job stored in the database. The classes of objects are readily determinable in common document formats used for print job submission, such as PDF.

Abstract: Digital fingerprinting using synchronization marks and watermarks. At a watermark embedder, an input host signal is divided into regions, and a subset of the regions is selected to receive synchronization marks. Respective synchronization marks are then embedded into the selected regions. At a receiver, an input signal is divided into regions, and a subset of the regions is synchronized with additional regions, which were defined by the embedder when producing the signal that is input to the receiver. Also, the receiver can model any geometric distortion undergone by the input signal between the embedder and the receiver.

Abstract: What is provided herein is a method for automatically selecting a subset of pages from a multi-page document for image processing wherein each selected page is substantially different from all other pages according to certain features of interest and wherein the combined content of the selected pages approximately represents the content in the entire document. Selected pages are clustered wherein each page is represented by a feature vector meaningfully related to the task to be performed. A matrix of feature vectors is analyzed. Basis vectors are extracted from the matrix using rank-reduction techniques. Clustering is performed by subspace projection of page features onto the basis vectors with each page being assigned to a cluster to which that page maximally projects. Representative pages are selected from each cluster. The representative pages can then be used as input to a secondary process.

Abstract: A method and system for identifying print jobs that are repeats of a previously completed job utilizing an object level hash table. Received print jobs can be parsed into meaningful classes of objects and a table of hash values can be computed for objects in each class and for each print job. A synopsis comprising the table of hash values can be retained in a database along with the job specific settings. A newly encountered job can be then declared as a repeat of a previous job based on the hashes for the new job that match the hash values for the previous job stored in the database. The classes of objects are readily determinable in common document formats used for print job submission, such as PDF.

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: An image digest based search approach allows images within an image repository related to a query image to be located despite cropping, rotating, localized changes in image content, compression formats and/or an unlimited variety of other distortions. In particular, the approach allows potential distortion types to be characterized and to be fitted to an exponential family of equations matched to a Bregman distance. Image digests matched to the identified distortion types may then be generated for stored images using the matched Bregman distances, thereby allowing searches to be conducted of the image repository that explicitly account for the statistical nature of distortions on the image. Processing, associated with characterizing image noise, generating matched Bregman distances, and generating image digests for images within an image repository based on a wide range of distortion types and processing parameters may be performed offline and stored for later use, thereby improving search response times.

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.