Hewlett-packard Company

Hewlett-packard Development Company, L.P.

Other

Brian E Hoffmann

Jeffrey L Trask

Scott C Clouthier

Qian Lin

Steven J Simske

Gary Lee Vondran, Jr

Randall Edward Grohs

Robert Douglas Christiansen

James R Nottingham

Douglas Heins

Brent Michael Bradburn

Marcus A Smith

Eugene Cohen

Richard H Benear

Paul Wissenbach

James A Kazakoff

Loay Abu-Husein

David A Martz

Robert E Stevahn, Jr

David S Pitou

Rulon G Esplin

Chris Lee

A method of transmitting a document from a computing device to a printing device using a document server comprising, at the server, receiving user credentials from a user of an authorized computing device, receiving encrypted data defining the document from the authorized computing device, receiving information indicating the intended recipients of the data, receiving user credentials from an authorized printing device, and delivering the encrypted data to an authorized recipient.

Transmitting a document

A firmware bundle is download to a non-operational storage area without changing a live copy of firmware in a device. The firmware bundle is downloaded in order to reboot the device to deploy one or more downloaded firmware packages from the non-operational storage area to the device, launch an Early Boot Installer manager to spawn and monitor the status of one or more Early Boot Installer processes contained in the firmware bundle download, determine in parallel whether a firmware install to one or more subsystems of the device is desire, and install the downloaded firmware package in parallel to one or more subsystems of the device.

Firmware installation

Systems and methods for cooperative rasterization of print data in an enterprise network are described. In one aspect, a primary printer rasterizes a portion of a print job to input raster bits into a raster buffer associated with the primary printer. During print job processing operations, the primary printer identifies a potential underflow condition of the raster buffer. Thus, the primary printer communicates an un-rasterized portion of the print job to a secondary printer for the secondary printer to rasterize&#x2014;the primary printer not rasterizing the un-rasterized portion. Subsequently, the primary printer receives raster bits corresponding to the un-rasterized portion from the secondary printer. The primary printer prints all of the raster bits corresponding to the print job.

Cooperative rasterization of print data in an enterprise network

Systems, apparatus, and methods for enhancing management of raster image processing (RIP) resources are described. In one aspect, a printing environment includes a RIP engine and multiple RIP pipelines. The RIP engine is scheduled to perform RIP for a first time period for a first pipeline of the multiple RIP pipelines. Responsive to occurrence of a start time of the first time period, the RIP engine is automatically transferred to the first pipeline for RIP.

Enhanced management of raster image processing resources

A computer peripheral device learning apparatus includes a host computer, a communication path, and a computer peripheral device. The host computer includes a peripheral device driver configured to generate an output job. The computer peripheral device communicates with the host computer via the communication path. The computer peripheral device is configured to generate an output job in a first output job format. Furthermore, the computer peripheral device is operative to receive instructions from an external source on how to generate an output job in a second output job format. A method is also provided.

Apparatus and method for enhancing learning ability and behavior for a computer peripheral device

An Adaptive Image Resolution Enhancement Technology (IRET) process and apparatus is described to improve halftone imaging by changing ordered halftone screen resolution according to the content of the image and managing these changes based on image content. The Adaptive IRET halftoning technique maximizes the artifact reducing properties of coarser ordered screens, while minimizing the loss of rendered detail in image areas having high spatial frequency. IRET may utilize a mixture of any ordered halftone screen (e.g. clustered-dot dither, line screen, etc.) to generate halftone dots with a number of levels, and any dispersed halftone screen to generate additional levels for the ordered halftone dots. For some printing technologies, it is preferable to minimize printing artifacts by generating coarser halftone screens, rather than finer halftone screens. Coarser screening, however, means that details in the image, text, and line art will not be rendered well. Adaptive IRET uses an activity index to change its ordered halftone screen resolution according to the content of the image. To render a page with a mixture of text, line art, area fill, and photograph, it is preferable to render the &ldquo;busy&rdquo; areas, such as text, line art, and edge regions in a photograph, with a higher resolution screen. On the other hand, smooth areas, such as area fill and non-edge regions in a photograph, are better rendered with a lower resolution screen.

Adaptive image resolution enhancement technology

A test page, system, and method are used to set a color density level of a laser printer, by producing a dot gain test pattern. The laser printer has at least one primary color. The dot gain test pattern is self-indicating and thus requires no external reference in order to determine a correct color density level. A preferred embodiment of the dot gain test pattern includes (a) a stable pattern having a color density which is stable with respect to changes in the laser printer operating conditions, and (b) a sensitive pattern having a color density which is sensitive to changes in the operating conditions, wherein the sensitive pattern in reference to the stable pattern indicates the density level of the laser printer for the at least one primary color. Additionally, in a preferred embodiment, the stable pattern includes a uniform coarse dot pattern, and the sensitive pattern includes a gradient of fine dot densities, the gradient printed adjacent to the coarse dot pattern, wherein a correct density level of the laser printer for the at least one primary color is indicated when a mid-spectrum area of the fine dot gradient appears to blend into the coarse dot pattern.

Self-indicating test page for use in setting density level and color

A method for halftoning an image to be rendered onto a media sheet includes the steps of: classifying data portions of a received data stream into one of plural image types, each image type to be subjected to a particular halftone procedure; assigning to each data portion of a common image type, a common identifier and then converting the data portions into a raster representation; subjecting segments of the raster representation to individualized halftone procedures, each segment of the raster representation that is assigned a common identifier being subjected to an identical halftone procedure; and rendering the raster representation onto a media sheet, subsequent to the halftone process. The apparatus for performing the halftone method places the halftone operation subsequent to the rasterization operation and thereby avoids anomalies which occurred in the prior art. Further, the apparatus enables halftone tables which are utilized during the halftone procedure to be altered so as to enable improvements to the halftone method.

Method and apparatus for halftoning of images in a printer

A print apparatus performs a halftoning action on a raster pixel image. The print apparatus includes a super-pixel data base for storing plural n.times.n superpixels, each superpixel corresponding to a subset (or 'bucket') of gray level pixel values. The method comprises the steps of: logically tiling a dither matrix across the raster pixel image and outputting a threshold value which, logically and positionally corresponds to a given image pixel value. The given image pixel value is then quantized into a selected bucket of pixel values which encompass the given image pixel value. A proportionality value is then determined which identifies the relative position of the given image pixel value within the selected bucket of pixel values. The outputted threshold value is then compared to the determined proportionality value, and the selected bucket number is incremented to a next sequential bucket number if the proportionality value exceeds the threshold value. A superpixel is next selected that is identified by the selected bucket number or the next sequential bucket number, as the case may be. A superpixel includes plural halftone pixel values and the method selects one of those halftone pixel values that is positioned at a location determinable from the coordinates of the given image pixel value. The selected halftone pixel value from the superpixel is then passed to the print engine of the printer for rendering. The method of the invention is carried out, preferably, by an application specific integrated circuit so as to enable high speed halftoning of the raster image.

Resolution enhancement procedure and apparatus for a color laser printer

A print data processing pipeline for use in a color electrophotographic printer optimizes print quality and minimizes memory usage by separately processing lossy and lossless print data. Lossy print data may include print data for images and lossless print data may include print data for text, line art, and graphics. Partitioning print data into lossy and lossless components allows application of the print data compression operations optimized for each type of print data. High compression ratios can be achieved on lossy print data by applying visually lossless compression operations designed for the lossy print data. In addition, high compression ratios can be achieved on the lossless print data by applying lossless compression operations designed for the lossless print data. A merge unit combines the lossy and lossless print data streams after decompression to reconstruct the original image. Placement of the color space conversion operation and the halftone operation relative to the merge operation, further optimizes the print quality while minimizing memory usage. The print data processing pipeline includes a direct memory access controller which has the capability to allow print data to be selectively directed to the lossy or lossless compressor/decompressor, the color space converter, or the merge unit. Feedback paths within the print data processing pipeline allow the results of the various operations performed to be returned to the direct memory access controller for further processing or storage in system memory. Bypass paths in the color space converter and halftone unit allow print data to be selectively directed around these operations. These capabilities allow configuration of the print data processing pipeline to perform a multitude of permutations of print data processing operations optimized for the print data.

Configurable data processing pipeline

Fine pulse width modulation (PWM) adjustments in the output of a laser printer are accomplished by receiving values from a bit map and modifying the values in accordance with values in a lookup table (LUT). The lookup table is subdivided into a plurality of blocks, and a selection of the blocks is made in accordance with external values. This allows the output of a pulse width modulation circuit to be adjusted to a precision that is greater than that afforded by the bit size of the values from the bit map. The use of plural blocks in the lookup table permits adjustments in the output of the pulse width modulation circuit in accordance with external factors such as relative humidity, sensitivity of an optical photoreceptor, and developer life.

Adjustment of dot size for laser imagers

A method and a system for generating a dither matrix calibrated to a desired tonal response. The method and system comprise generating a dither matrix with a predicted tonal response, measuring the actual tonal response, manipulating a cumulative histogram for the dither matrix in response to the actual tonal response, and inputting the cumulative histogram to a dither matrix generation program to generate a dither matrix that conforms to the cumulative histogram. Other systems and methods are disclosed.

System and method for generating calibrated dither matrices

A binary pixel bitmap image is converted to a multi-bit gray level pixel image at a level of resolution that is reproducible by a laser printer. An edge smoothing procedure is employed by the laser printer and comprises the steps of: deriving from font contours of the image, a binary pixel bitmap of the image at a higher level of resolution than is output by the laser printer; logically stepping an m.times.n pixel window across pixel groups of the higher resolution binary pixel bitmap and, at each step, determining a count of pixels of one binary kind that are present within the pixel window; converting each count of pixels to a corresponding modulation signal; and controlling a laser in the laser printer in accordance with each modulation signal so that an edge smoothed gray level image is produced at the printer's level of output resolution.

Growing community of inventors

Boise, ID, United States of America

Brian E Hoffmann