Abstract: A system of estimating and reducing image blur in digital images.

Abstract: Geometric configurations for photosites found on photosensitive chips for creating electrical signals from an original image, as would be found, for example, in a digital scanner, copier, facsimile machine, or other document generating or reproducing device. The photosensitive chips are mounted on a substrate to form a photosensitive array in a full width scanner or other photosensitive device. The geometric configurations reduce the Moiré patterns to provide a higher quality image.

Abstract: Geometric configurations for photosites found on photosensitive chips for creating electrical signals from an original image, as would be found, for example, in a digital scanner, copier, printer, facsimile machine, or other document generating or reproducing device. The photosensitive chips are mounted on a substrate to form a photosensitive array in a full width scanner or other photosensitive device. The geometric configurations reduce the Moiré patterns to provide a higher quality image.

Abstract: A document-backing surface for reducing show-through when a duplex-printed document is scanned but without producing undesirable artifacts. The document-backing surface has a plurality of first and second light-absorbing surfaces, and a plurality of specularly reflective surfaces partially covering each of the second light-absorbing surfaces. The first specularly reflective surfaces are oriented to reflect light from a scanner lamp to a scanner sensor. In an alternate embodiment, the document-backing surface is partially covered by a specularly reflective surface oriented to reflect light from the scanner lamp to the scanner lens. In another embodiment, the document-backing surface has a set of teeth, each of which has light-absorptive first and second tooth surfaces and a specularly reflective surface partially covering each second tooth surface. In addition, the present invention is directed to a method for using a document-backing surface.

Abstract: A method for background adjustment. A background lightness level in an original image is estimated. Pixels are then converted to a luminance-chrominance color space. Pixels have lightness levels equal to the background lightness level are mapped to a value corresponding to white as background pixels. Chroma values for the background pixels are compared to a threshold ad adjusted as needed, either by adjusting the lightness value or by removing the chrominance values. The luminance-chrominance data is then converted to output space.

Abstract: The present application relates to document boundary determination.

Abstract: A method for super-resolution scanning in a image capturing device includes capturing a first color component of the image at one-half of a full resolution, capturing a first luminance component at one-half of the full resolution, and generating a first color-luminance output signal therefrom; capturing a second luminance component of the image at the full resolution and generating a luminance output signal therefrom; capturing a second color component of the image at one-half the full resolution, capturing a third luminance component of the image at one-half the full resolution, and generating a second color-luminance output signal therefrom; converting the first and second luminance components of the first and second color-luminance output signals and the third luminance component signal to a luminance component signal of 2X full resolution; and processing the full resolution output signals and the 2X full resolution output signal to form a combined output signal.

Abstract: A method and system implements a high addressability characteristic into an error diffusion process. A histogram of the image is generated and the actual background and black reference values are determined. A gray level value representing a pixel is received. The gray level value has a first resolution which corresponds to an original input resolution. The gray level value is interpolated to generate subpixel gray level values which correspond to a second resolution. The second resolution is higher than the first resolution and corresponds to the high addressability characteristic. A threshold circuit thresholds the interpolated gray level value and generates an error value as a result of the threshold using the determined background and black reference values. The error value has a resolution corresponding to the first resolution. A portion of the error value is diffused to adjacent pixels on a next scanline.

Abstract: A method and system automatically determines the width (i.e., left and right edges) of a document when it is loaded for scanning or copying. When a document is staged, the scanner collects a predetermined number scanlines of the leadedge of the document. Both first order and second order statistics of the scanner and document are then calculated based on the scanned data. The auto-width detection process is adaptive to CCD sensor output variation, document variation, and scanner variation, thus making it robust against dust in the sensor path and random fluctuations of the scanner.

Abstract: A method and system automatically determines proper background values for a document. A histogram of the document is generated and it is determined whether a background characteristic of the document is uniform. If the background is uniform, a white background value is set equal to a first calculated white peak value. If the background is non-uniform, the white background value is set equal to a second calculated white peak value. A foreground value of the document is analyzed for validity when it is determined that a background characteristic of the document is uniform. A black background value is set equal to a black peak value calculated from the histogram when it is determined that a foreground value of the document is valid.

Abstract: A printing system for rendering marks on a recording medium receives a multi-level grey scale pixel value representing a pixel having a first resolution. A screening circuit generates a screened multi-level grey scale pixel value equal to (G.sub.L -V.sub.i)+(S.sub.i -Th)*Dmp.sub.vi *Mod.sub.Eff wherein G.sub.L is the maximum grey level value of the pixel, V.sub.i is equal to the multi-level grey scale pixel value of the first resolution, S.sub.i is equal to a screen value corresponding to a position of the pixel, the image classification of the pixel and a brightness/darkness setting, The threshold value, Dmp.sub.vi is a video dependent dampening factor, and Mod.sub.Eff is a modulation multiplication factor.