Hewlett-packard Company

Hewlett-packard Development Company, L.P.

Cypress Semiconductor Corporation

In-system Design, Inc.

James R Nottingham

Gary Lee Vondran, Jr

Douglas Heins

Brian E Hoffmann

Scott C Clouthier

James G Eldredge

Dee Lee Chou

Richard H Benear

Calvin K McDonald

Ronald L Hall

Billy L Knorpp

Phil Dilmore

Apparatuses, systems, and methods are provided for processing data. In one method embodiment, the method includes defining a number of color channels, each channel to transfer a particular color element of a stream of color type pixel data. The method can also include identifying monochrome type pixel data within a data stream and allocating a color channel to transfer the identified monochrome type pixel data.

Monochrome and color transfer

A method and apparatus enhance a color or grayscale raster image in a printer by identifying a working pixel in the raster image for anti-aliasing, and then modifying luminance data of the working pixel in a luminance chrominance color space such that an anti-aliasing effect is achieved relative to the raster image. The luminance component of the raster image data is converted to a binary format to identify the working pixel using RET template matching. The luminance data of the working pixel is modified by utilizing luminance data of adjacent pixels to produce a new luminance value which is then assigned to the working pixel. One of the adjacent pixels defines an edge of the object being anti-aliased in the raster image, and the other of the adjacent pixels defines an edge of a region in the raster image that is adjacent the object. In the event chroma data is associated with the object, the chroma data is combined with the modified luminance data and also assigned to the working pixel for accurate imaging thereof.

Luminance-based color resolution enhancement

Parallel peripheral interface

A hybrid bilinear scaling (Qscale) scheme produces output images that have comparable quality to traditional bilinear interpolation algorithms, but requires a less complex hardware implementation. The Qscale system does not reverse-map output pixels back to arbitrary locations in the input space as defined by the mapping function. Rather all pixel values and locations are calculated after all of the original input pixels are mapped to the output. That is, all of the original image pixels are used &ldquo;as-is&rdquo; in the resultant scaled image. New pixels are generated from the original input pixels to meet the desired output pixel dimensions. Because only new pixels are computed, the Qscale system is less computationally complex. The computational requirements are further reduced because new pixels are computed between original pixel pairs meaning only two pixels are involved in the computation. Coefficients can be chosen to be fractional powers of two (0.5, 0.25, 0.125, etc) for the interpolation calculation between pixel pairs. By selecting coefficients this way, the linear computation reduces to a &ldquo;shift-and-add&rdquo; operation, which is easily implemented in hardware.

Hardware-efficient system for hybrid-bilinear image scaling

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 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.

Data merge unit

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 or 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.

Multi-path data processing pipeline

Configurable data processing pipeline

A printing media position sensing device provides sheet medium position status information for synchronizing media transfer operations in a hard copy machine using a sheet feeder system. When a sheet is picked and transferred from a stack in a replaceable cartridge, refillable tray, or the like, to the input registration and feed mechanism of the hard copy machine, a detector senses the further exit motion of the picked sheet, thus providing an indication that the input registration and feed mechanism has taken control of the sheet. A signal indicative of this condition is used to release the sheet pick and transfer mechanism associated with the stack so that the sheet is free to leave the stack uninhibited. The exit sensor automatically resets for the next cycle.

Growing community of inventors

Boise, ID, United States of America

James R Nottingham