Eastman-kodak Company

Thomas J Wetzel

Gregory Rombola

Russell L Godshalk

Hwai-Tzuu Tai

Rodney L Miller

Roger A Morton

James R Sullivan

Lawrence B Telle

Frank L Muster

Raymond E Maslinski

Larry L Christensen

Mark J Jablonski

The registration and skew information of a document about to be scanned are detected prior to capturing the entire image of the document. Two sensors, a fixed distance apart, are used to detect the document skew. A third sensor is used to detect the edge position of the document. Paper sensors in the Automatic Document Feeder (ADF) are used to determine the document size. The data from the skew sensors are used to calculate the required skew correction angle and direction by which to rotate the image. The document edge position information together with skew information is used to determine the exact location of a corner of the document. This information is used to correct skewed image in real-time, during scanning the document.

Real time electronic registration of scanned documents

A method and apparatus for processing image data of pixels to be rendered for efficient storage in a memory or efficient transmission wherein a grey level value of a rendered pixel is represented by multiple bits including a most significant bit (MSB) and a least significant bit (LSB). The method and apparatus provide for modifying of the density values of successive pixels in accordance with an error diffusion operation. The modified density values are then subject to a thresholding operation wherein the thresholding operation employs position of a pixel to determine the digital value of the LSB of the rendered pixel. There is thereby provided a pattern structure to the LSB data. The rendered pixel values may then be compressed to provide for efficient storage in a memory or for efficient transmission over a communication pathway. The invention thus relates to improving the compressibility of the total image data by imparting structure to at least rendered image data where the error diffusion process would normally remove any structure to the LSB's of the image.

Method and apparatus for increasing compressibility of multibit image

An apparatus and method for processing image data operates in a high capacity or a high quality mode. In the former a single bit per pixel is created and processed along one of two identical processing paths. The processing paths involve compression, buffering and expansion for output to a writer interface. The processing path selected for pixels in each image frame is in accordance with the most available buffering memory. In the latter mode two bits per pixel, a more significant bit (MSB) and a less significant bit (LSB) are created and processed simultaneously along the two processing paths. The processing path for each is selected in accordance with the LSB being processed by the processing path with the most available memory. As compression of the LSBs is not as efficient as that of the MSBs, the number of document pages stored in the compression buffers is maximized.

Marking engine for grey level printing having a high productivity image

An apparatus and method for processing image data operates in a high capacity mode or a high quality mode. In the former a single bit per pixel is created and processed along one of two identical processing paths. The processing paths involve compression, buffering and expansion for output to a writer interface. The processing path selected for pixels in each image frame is in accordance with the most available buffering memory. In the latter mode two bits per pixel, a more significant bit (MSB) and a less significant bit (LSB) are created and processed simultaneously along the two processing paths. The processing path for each is selected in accordance with the LSBs being processed by the processing path with the most available memory. As compression of the LSBs is not as efficient as that of the MSBs, the number of document pages stored in the compression buffers is maximized.

Method and apparatus for maximizing data storage in a processor of image

A halftoning method for creating a color binary image from a continuous tone color image or computer generated graphics signal is improved by diffusing color vector error and by including the visual color blur functions in the recursive error propagation algorithm so that perceived color vector rather than binary color error is propagated.

Color digital halftoning with vector error diffusion

Thresholding and background referencing apparatus are disclosed for use with apparatus for scanning documents having images with object and background regions. The background referencing apparatus receives, from the scanning apparatus, a video signal representing the document image and generation a signal having a value representative of an estimate of the background density level of the document being scanned. The apparatus produces a difference signal representative of the difference between the estimated background level signal and the received video signal. The estimated background level signal is stored, and updated in response to (1) the difference signal being of a first sign associated with transition from object to background, and (2) only small difference signals of a second sign associated with transition from background to object, whereby large difference signals of the second sign result in substantially no change in the stored estimated background level signal.

Growing community of inventors

Rochester, NY, United States of America

Thomas J Wetzel