Abstract: A method adapts image data using more than eight bits per pixel to be compatible with devices using only 8-bit per pixel data. The method separates the higher bit depth data into an 8-bit image data stream, the balance of the bits are carried in a separate tag data stream. The 8-bit image data stream can be used in legacy devices that can handle only 8-bit data, and the tag data stream can be used in legacy devices that incorporate a tag data stream for their internal image processing.

Abstract: A method adapts image data using more than eight bits per pixel to be compatible with devices using only 8-bit per pixel data. The method separates the higher bit depth data into an 8-bit image data stream, the balance of the bits are carried in a separate tag data stream. The 8-bit image data stream can be used in legacy devices that can handle only 8-bit data, and the tag data stream can be used in legacy devices that incorporate a tag data stream for their internal image processing.

Abstract: 4+ color management sequentially processes four colors at a time from among the 4+ colors to leverage solution capability using a 4-color management tools. In methods and apparatus for processing 4+ colors, received information of 4+ colors may be processed in a first stage using four colors of the 4+ colors, such as CMYO. The processed four colors are then mapped into three virtual colors. The mapped three virtual colors and one additional unprocessed color of the 4+ colors are then processed in a second stage using a 4-color tool. From this, a second color model of at least five colors (4+) is generated. The resulting four colors determine five printer colors, and are then mapped into three virtual colors. The mapped three virtual colors and one additional unprocessed color of the 4+ colors are then processed in a third stage using a 4-color tool. From this, a third color model of at least five colors (4+) is generated.

Abstract: A color management method, system and storage medium output 4+ color separation signals to a 4+ (5 or more) color print engine. An input source color is converted into virtual intermediate CMYK separation signals using a 4-color management tool, which may be a conventional tool. These virtual intermediate CMYK separation signals are received as input within a digital front end (DFE), which transforms the intermediate signals into 4+ separation signals, such as for a 6-color print engine. A transformation unit of the DFE passes some of the input separation signals through directly as output (without transformation) while transforming others by splitting them into light and dark separation signals, such as light and dark cyan or magenta using a blend curve that will output the same tonal quality. The transformation unit may use a blending curve that takes into account ink-limit constraints and may maximize light colorant usage to improve image smoothness in light image regions.

Abstract: A xerogrpahic system and method use a tri-level development process in which at least one xerographic imaging unit includes a photoreceptor and a pair of developer units. A first developer unit includes a conventional first toner of a given color (CYMK) and a second developer unit includes a hypochromatic light form of the first toner. By use of a specific tri-level process, excellent color-to-color registration can be achieved for each processed color separation because overlap between colorants can be prevented. Moreover, by use of two forms of the same colorant, a smoother tone reproduction curve can be achieved when an aggressive blending strategy is used. Gamut loss and ink limit violation can be avoided by adjusting the blending curve in certain situations.

Abstract: The present invention is a method and apparatus for processing image data to accomplish tuning or adjustment of images, so as to modify at least the darkness thereof, using compact, efficient methods and designs.

Abstract: 4+ color management sequentially processes four colors at a time from among the 4+ colors to leverage solution capability using a 4-color management tools. In methods and apparatus for processing 4+ colors, received information of 4+ colors may be processed in a first stage using four colors of the 4+ colors, such as CMYO. The processed four colors are then mapped into three virtual colors. The mapped three virtual colors and one additional unprocessed color of the 4+ colors are then processed in a second stage using a 4-color tool. From this, a second color model of at least five colors (4+) is generated, The resulting four colors determine five printer colors, and are then mapped into three virtual colors. The mapped three virtual colors and one additional unprocessed color of the 4+ colors are then processed in a third stage using a 4-color tool, From this, a third color model of at least five colors (4+) is generated.

Abstract: A first series of control patches is printed with a first marking engine. A second series of control patches is printed with a second marking engine. Relative reflectance values of the patches printed with the first and second marking engines are measured with respective first and second engine response sensors. Based at least on a difference in the measured relative reflectance values of the control patches printed with the first and second marking engines, a relative engine to engine error is determined. The engine to engine error is decomposed into components. Based on the decomposition, adjustment of at least binary values of a digital image is determined so that print density of a first marking engine output substantially matches print density of a second marking engine output.

Abstract: Disclosed herein is an image processing method for producing enhanced halftone edges, particularly suited to those edges which only lie upon the background as apposed to those edges which abut other halftone screens. It utilizes a step of defining border pixels and a step of halftoning those border pixels in a different manner than the halftoning applied to the interior region of the tint or image segment. The preferred halftone for the border pixels will be related to the interior halftone by some number of common spatial frequency harmonics.

Abstract: A xerogrpahic system and method use a tri-level development process in which at least one xerographic imaging unit includes a photoreceptor and a pair of developer units. A first developer unit includes a conventional first toner of a given color (CYMK) and a second developer unit includes a hypochromatic light form of the first toner. By use of a specific tri-level process, excellent color-to-color registration can be achieved for each processed color separation because overlap between colorants can be prevented. Moreover, by use of two forms of the same colorant, a smoother tone reproduction curve can be achieved when an aggressive blending strategy is used. Gamut loss and ink limit violation can be avoided by adjusting the blending curve in certain situations.

Abstract: A color management method, system and storage medium output 4+ color separation signals to a 4+ (5 or more) color print engine. An input source color is converted into virtual intermediate CMYK separation signals using a 4-color management tool, which may be a conventional tool. These virtual intermediate CMYK separation signals are received as input within a digital front end (DFE), which transforms the intermediate signals into 4+ separation signals, such as for a 6-color print engine. A transformation unit of the DFE passes some of the input separation signals through directly as output (without transformation) while transforming others by splitting them into light and dark separation signals, such as light and dark cyan or magenta using a blend curve that will output the same tonal quality. The transformation unit may use a blending curve that takes into account ink-limit constraints and may maximize light colorant usage to improve image smoothness in light image regions.

Abstract: In an image processing method, a first raster having a first resolution is divided into a plurality of sub-sampling cells each containing a selected number of neighboring pixels. A pixel from each of the sub-sampling cells is selected in a periodic or quasi-periodic pattern biased toward selecting a pixel position within each sub-sampling cell that is distal from a selection position within at least one neighboring sub sampling cell. The selected pixels define a second raster having a second resolution lower than the first resolution.

Abstract: A method of adjusting a TRC of an image is provided. The method involves receiving an image at an input resolution, resampling the image to a processing resolution if the imput resolution and the processing resolution are not same, processing the image using rank-ordered error diffusion, and resampling the processed image to a desired output resolution for the image if the processing resolution and the output resolution are not same.

Abstract: The present invention is a method and apparatus for processing image data to accomplish tuning or adjustment of images, so as to modify at least the darkness thereof, using compact, efficient methods and designs.

Abstract: The present invention is a method and apparatus for processing image data to accomplish tuning or adjustment of images, so as to modify at least the darkness thereof, using compact, efficient methods and designs.

Abstract: A method and system for converting, transforming or translating an imaging element associated with a first resolution into a second imaging element associated with a second resolution are provided. The method and system provide for the selection of output imaging element pattern based on context information extracted from areas neighboring an area undergoing conversion when information extracted from the area undergoing conversion provides an insufficient basis from which to select an output imaging element pattern. Exemplary embodiments are directed toward preservation of area coverage and centroid placement. The method provides for consideration of characteristics of a marking engine in the output imagine element pattern selections process. In xerographic environments clustering can be maximized, thereby reducing xerographic stress. In inkjet environments output pattern selections can be directed toward decreased clustering.

Abstract: There is disclosed in embodiments methods for halftone dot encoding for engine-dependent-rendering. The methods first carefully design an asymmetric halftone dot for a specific printer and then utilizes a halftone dot encoding algorithm, which encodes the asymmetric halftone dot into a symmetric format. The asymmetric halftone dot design is satisfies the requirements of raster output scanner electronics, as well as several engine dependent constraints. These include: rotation insensitivity, minimum dot size, minimum hole size, minimum appendage, and minimum cavity. The symmetric dot encoding allows perfect reconstruction of the binaries that may have been generated using the original asymmetric dot. This reconstruction is achieved using imbedded binary resolution conversion. In this way, this resolution conversion is acting as a decoder.

Abstract: A method and system for converting, transforming or translating an imaging element associated with a first resolution into a second imaging element associated with a second resolution are provided. The method and system provide for the selection of output imaging element pattern based on context information extracted from areas neighboring an area undergoing conversion when information extracted from the area undergoing conversion provides an insufficient basis from which to select an output imaging element pattern. Exemplary embodiments are directed toward preservation of area coverage and centroid placement. The method provides for consideration of characteristics of a marking engine in the output imagine element pattern selections process. In xerographic environments clustering can be maximized, thereby reducing xerographic stress. In inkjet environments output pattern selections can be directed toward decreased clustering.