Abstract: A method and apparatus for compressing a mixed raster content image that represents a color or gray scale a document is disclosed. The pixel map is decomposed into a three-plane representation—a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. An iterative smoothing technique is then used to pre-process the upper and lower planes using the information contained in the selector plane, thereby reducing the amount of data that will be subjected to further processing.

Abstract: A method and device for describing a complex color raster image as a collection of objects in a hierarchical and device independent format can be carried out using an apparatus for generating an image capable of being displayed and printed.

Abstract: A period-based method for converting digital image data for a plurality of pixels from a first bit depth to a second bit depth includes receiving an input scanline of an arbitrary length comprising digital image data for a plurality of input image pixels. Each of the input image pixels is defined at the first bit depth. The input scanline is divided into a plurality of periods each comprising digital image data for a select number of input image pixels. The period is selected so that the image data for the select number of input image pixels exactly comprises m bytes when defined at the first bit depth and exactly comprises n bytes when defined at the second bit depth, wherein m and n are different integers. For each of the periods in succession, the image data for each of the select number of input image pixels is converted from the first bit depth to the second bit depth.

Abstract: An improved technique for processing a color or gray scale pixel map representing a document is disclosed. The pixel map is decomposed into a three-plane representation, a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. The “upper” and “lower” planes contain the color or gray scale for the page as well as the continuous tone pictures that are contained on the page. The selector plane stores information for selecting from either the foreground plane or background plane during decompression. Information contained in the selector plane is first used to pre-process the upper and lower planes to reduce the amount of data on each of the other two planes that will be subjected to further processing. Each of the pre-processed planes is compressed using a compression technique optimal for the type of data that resides upon it.

Abstract: An improved technique for processing a color or gray scale pixel map representing a document is disclosed. The pixel map is decomposed into a three-plane representation, a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. The “upper” and “lower” planes contain the color or gray scale for the page as well as the continuous tone pictures that are contained on the page. The selector plane stores information for selecting from either the foreground plane or background plane during decompression. Information contained in the selector plane is first used to pre-process the upper and lower planes to reduce the amount of data on each of the other two planes that will be subjected to further processing. Each of the pre-processed planes is compressed using a compression technique optimal for the type of data that resides upon it.

Abstract: An improved technique for processing a color or gray scale pixel map representing a document is disclosed. The pixel map is decomposed into a three-plane representation, a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. The “upper” and “lower” planes contain the color or gray scale for the page as well as the continuous tone pictures that are contained on the page. The selector plane stores information for selecting from either the foreground plane or background plane during decompression. Information contained in the selector plane is first used to pre-process the upper and lower planes to reduce the amount of data on each of the other two planes that will be subjected to further processing. Each of the pre-processed planes is compressed using a compression technique optimal for the type of data that resides upon it.

Abstract: An improved technique for processing a color or gray scale pixel map representing a document is disclosed. The pixel map is decomposed into a three-plane representation, a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. The “upper” and “lower” planes contain the color or gray scale for the page as well as the continuous tone pictures that are contained on the page. The selector plane stores information for selecting from either the foreground plane or background plane during decompression. Information contained in the selector plane is first used to pre-process the upper and lower planes to reduce the amount of data on each of the other two planes that will be subjected to further processing. Each of the pre-processed planes is compressed using a compression technique optimal for the type of data that resides upon it.

Abstract: A method and apparatus for compressing a mixed raster content image that represents a color or gray scale a document is disclosed. The pixel map is decomposed into a three-plane representation—a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. An iterative smoothing technique is then used to pre-process the upper and lower planes using the information contained in the selector plane, thereby reducing the amount of data that will be subjected to further processing.

Abstract: A scheme that generates image processing source code for custom applications automatically by using structured image (SI) technology in a way that takes advantage of the unbound and incomplete features of SI. Resulting custom applications developed by this method can be defined and converted to running source code in minutes, or shipped to a co-user of the system in a compact portable form for remote code generation.Nested sub-component references and associated image processing operations necessary to generate an output raster image are obtained from a structured image template. Image processing operations and the order of said operations within an image processing definition are stored within the structured image definition. Unbound structured image references to undefined component objects and incomplete structured image references to image processing operations and parameters not explicitly defined within said structured image are input options.

Abstract: A scanner generates a first set of M-bit signals representing an image in a document. A default table translates the M-bit signals into linearized N-bit signals where M>N. A color image processing module processes the N-bit signals to generate an image-dependent look-up table which, thereafter, is loaded into the scanner. The scanner then generates a second set of M-bit signals using a high resolution re-scan of the same image. The second set of M-bit signals are translated into N-bit signals using the image-dependent look-up table to generate an electronic representation with enhancement characteristics.

Abstract: An editing process and device for modifying images in the structured image (SI) format. The image editor can perform image processing operations, transparency and geometric transform to objects. The underlying SI format allows the image editor to be memory efficient with unlimited undo capability.

Abstract: A method of improving the contrast in a natural scene image. A relevant histogram of the image is derived for from a selected subset of local histograms representing regions of the image. The signal describing the histogram is operated on with a filter having the characteristic of weakening strong peaks and valleys in the function, but not effecting flat portions of the signal. The filtered histogram signal is used for controlling the TRC mapping in a device at which the image is to be printed. To assure optimum selection of local histograms, regions including the black point and white point of an image are determined and added to the subset of local histograms representing regions of the image.

Abstract: A method and device for describing a complex color raster image as a collection of objects in a hierarchical and device independent format. The purpose of structured imaging (SI) is to expand the scope of a raster image to a collection of individually manipulable component objects. An SI is a hierarchical description of a single output image raster which may be used as one component of a page in a structured document. Objects contributing to the output raster may originate from text, graphics, other rasters or a combination thereof, and all maintain their heritage for selectability and modification. The SI describes not only the source data but also the image processing operations required for rendering the output raster. SI technology supports re-editability, customization and enhancement, automatic image assembly and high performance imaging. Thus, such a model has implications not only in an image editing and processing arena, but also in the filing and printing services used for image handling.

Abstract: A method of improving the contrast in a natural scene image, in which the image is converted from an original set of color coordinates to an expression where one term has a relationship to overall image intensity. A global histogram of the image is derived for that term, which plots the populations of pixels at each possible level of intensity in the image. The signal describing the histogram is operated on with a filter having the characteristic of weakening strong peaks and valleys in the function, but not effecting flat portions of the signal. The filtered histogram signal is used for controlling the TRC mapping in a device at which the image is to be printed. Contrast is improved in areas likely to have the most image information, using the method described above, and further, dividing the image into a number of segments, each describable by a local histogram signal for that image segment. Each local histogram signal is compared to the global histogram, to determine which signals are flatter.

Abstract: A method of altering the sharpness in the reproduction of an electronically encoded natural scene image, including process steps of: a) converting the signals to a luminance-chrominance signal format, wherein at least one signal represents overall image intensity; b) determining the maximum local contrast within the image; c) determining a filter function applicable to the image which increases maximum local contrast to a predetermined target value, and all other contrast to an amount proportional thereto; and d) applying the determined filter function to the image to increase sharpness thereof.

Abstract: A method of improving processing of a color natural scene image defined by color density signals processed by multiple processing elements, wherein after an exposure processor incorporates a luminance signal histogram, a modifying TRC curve is derived and applied to the luminance histogram signal. The resultant modified luminance histogram signal is blurred prior to directing it to a contrast processor. The modifying TRC curves determined at each processor are combined and applied to the color density signals only after combination.