Abstract: A method is provided for enhancing a grayscale raster image comprising pixels. The method comprises the steps of composing a second raster image of equal dimensions to said raster image, selecting a target pixel in the second raster image, having a target position, and deriving a grayscale value for the target pixel from a grayscale value of a pixel in said raster image that is in a neighborhood of a pixel on a position corresponding to the target position, thereby dispersing the gray value of a pixel in a predetermined range around its original position and working the second raster image up for a halftoning process without using pixel segmentation.

Abstract: A method for converting a full color image to a monochrome image is provided, wherein the color values of pixels are decomposed in a luminance and a chrominance component. Both components are converted to a grayscale value representing an intensity of a pixel. The luminance grayscale value is in a limited range close to a light end of the available grayscale. The chrominance grayscale value is closer to the dark end of the available grayscale when the chrominance component of the color value is larger. The darkest value of the two converted values is selected for a corresponding pixel. The effect of this conversion is that colored pixels are darker than colorless pixels, which is useful to highlight parts of a monochrome image that stand out because of their color in a full color image. It is particularly useful to help color blind people recognize colored parts of an image.

Abstract: A method is provided for enhancing a grayscale raster image comprising pixels. The method comprises the steps of composing a second raster image of equal dimensions to said raster image, selecting a target pixel in the second raster image, having a target position, and deriving a grayscale value for the target pixel from a grayscale value of a pixel in said raster image that is in a neighborhood of a pixel on a position corresponding to the target position, thereby dispersing the gray value of a pixel in a predetermined range around its original position and working the second raster image up for a halftoning process without using pixel segmentation.

Abstract: In a method of scanning an image on an original, an optical sensor including sensor elements for each of a number of basic colors is used to generate pixel values of rows of pixels of the scanned image. The sensor elements are used to generate grey scale pixel values representing different parts of the image. A first sensor element for each of the basic colors is used to generate pixel values of odd pixels of rows on the original, and a second sensor element for each of the basic colors is used to generate pixel values of even pixels of rows of the original. Each color pixel value is generated mainly on the basis of a pixel value of at least one of the first sensor elements and pixel values of at least two of the second sensor elements for adjacent pixels.

Abstract: A method is provided for reducing a background in a raster image as generated from capturing a hardcopy original. The background indicates a deviation between a lightness value of a subset of pixels in the raster image and a maximum lightness value of raster image input values, contrasting with dark information in the image. Two areas around the target pixel are defined, one area being substantially smaller than the other. An average of a lightness value of the pixels in each of the two areas are combined to obtain a background parameter, indicating a locally varying background in the raster image. A target pixel lightness value is scaled using the background parameter and the maximum lightness value.

Abstract: A method is provided for reducing a background in a raster image as generated from capturing a hardcopy original. The background indicates a deviation between a lightness value of a subset of pixels in the raster image and a maximum lightness value of raster image input values, contrasting with dark information in the image. Two areas around the target pixel are defined, one area being substantially smaller than the other. An average of a lightness value of the pixels in each of the two areas are combined to obtain a background parameter, indicating a locally varying background in the raster image. A target pixel lightness value is scaled using the background parameter and the maximum lightness value.

Abstract: A method for converting a full color image to a monochrome image is provided, wherein the color values of pixels are decomposed in a luminance and a chrominance component. Both components are converted to a grayscale value representing an intensity of a pixel. The luminance grayscale value is in a limited range close to a light end of the available grayscale. The chrominance grayscale value is closer to the dark end of the available grayscale when the chrominance component of the color value is larger. The darkest value of the two converted values is selected for a corresponding pixel. The effect of this conversion is that colored pixels are darker than colorless pixels, which is useful to highlight parts of a monochrome image that stand out because of their color in a full color image. It is particularly useful to help color blind people recognize colored parts of an image.

Abstract: A method for converting a hard copy original to a digital image by a scanner system having an image line sensor and a transport system for transporting the hard copy original across the image line sensor are provided. The scanner system has several modes of operation, each mode being associated with a predefined original type and each mode assembling either grey lines or color lines for composing the digital image. The method includes determining an optimal mode of operation for converting the hard copy original by transporting a first part of the hard copy original across the image line sensor. Grey lines from the image line sensor are used in the determination, because this allows the hard copy original to be transported three times as fast across the image line sensor. It is still possible to discern originals with color information from scanned originals with only black-and-white information.

Abstract: A processing unit for an image processing apparatus enables the reduction of background noise or disturbances on a scanned image. The processing unit is arranged to apply an image enhancement method to the luminance image data of the scanned image only and merge the obtained modified luminance image data with additional luminance image data obtained from the chrominance image data so as to recover light shades on the background that may have been removed by the image enhancement method.

Abstract: In a method of scanning an image on an original, an optical sensor including sensor elements for each of a number of basic colors is used to generate pixel values of rows of pixels of the scanned image. The sensor elements are used to generate grey scale pixel values representing different parts of the image. A first sensor element for each of the basic colors is used to generate pixel values of odd pixels of rows on the original, and a second sensor element for each of the basic colors is used to generate pixel values of even pixels of rows of the original. Each grey scale pixel value is generated mainly on the basis of a pixel value of at least one of the first sensor elements and a pixel value of at least one of the second sensor elements for adjacent pixels.

Abstract: In a method of scanning an image on an original, an optical sensor including sensor elements for each of a number of basic colors is used to generate pixel values of rows of pixels of the scanned image. The sensor elements are used to generate grey scale pixel values representing different parts of the image. A first sensor element for each of the basic colors is used to generate pixel values of odd pixels of rows on the original, and a second sensor element for each of the basic colors is used to generate pixel values of even pixels of rows of the original. Each grey scale pixel value is generated mainly on the basis of a pixel value of at least one of the first sensor elements and a pixel value of at least one of the second sensor elements for adjacent pixels.

Abstract: In a method of scanning an image on an original, an optical sensor including sensor elements for each of a number of basic colors is used to generate pixel values of rows of pixels of the scanned image. The sensor elements are used to generate grey scale pixel values representing different parts of the image. A first sensor element for each of the basic colors is used to generate pixel values of odd pixels of rows on the original, and a second sensor element for each of the basic colors is used to generate pixel values of even pixels of rows of the original. Each color pixel value is generated mainly on the basis of a pixel value of at least one of the first sensor elements and pixel values of at least two of the second sensor elements for adjacent pixels.

Abstract: A processing unit for an image processing apparatus enables the reduction of background noise or disturbances on a scanned image. The processing unit is arranged to apply an image enhancement method to the luminance image data of the scanned image only and merge the obtained modified luminance image data with additional luminance image data obtained from the chrominance image data so as to recover light shades on the background that may have been removed by the image enhancement method.

Abstract: A document scanning system includes a scan apparatus adapted to scan a document and to create and store electronic raw data representing the scanned document. An input system permits a user to input settings for the scanned document. A start mechanism causes the scan apparatus to start a scan process. A a processing unit is adapted to process the raw data and to create a formatted document file representing the scanned document. The input system is adapted to permit the user to input format settings for a document after the start mechanism has started the scan process for that document, and the processing unit is adapted to process the raw data in accordance with the format settings.