Oce-technologies B.v.

Canon Production Printing Holding B.v.

Oce-technology B.v.

Maurice L M Luttmer

Jan H Geels

Ernst P Van Horssen

Matthieu W J Helder

Julien Malik

Philippe Sobczak

A method for calibrating and converting colors of a digital image into printer specific colorant control values is disclosed. This method comprises the steps of calibrating a specific printer of a printer type according to a printer type specific procedure, wherein for each colorant separately a one-dimensional relationship between a printer tone value and a colorant control value is established; profiling the printer type to establish an output profile that defines a relationship between color values in a profile connecting color space and the printer tone values; deriving from the input profile and the output profile a one-dimensional relationship between a black channel and the black printer tone value of the printer; determining if an image color value is to be converted either by using the profiles or by using the one-dimensional relation; converting the image color value and subsequently using the printer calibration relations to obtain the colorant control values. This procedure enables the use of G7 colors in a printer that is limited in its amount of colorant that can be applied locally.

Method for calibrating and converting CMYK colors

A method for processing with a document processing system is provided. The method includes generating a sheet assembly by executing a production route model of at least one function leading to a plurality of actions, the sheet assembly including a set of transitions that result from invocation of the plurality of actions, extracting from the sheet assembly a document imposition recipe including a set of imposition descriptions generated by computing transformations and parameters for each transition performed on the sheet assembly, and rendering the imposition descriptions of the document imposition recipe on behalf of at least one source file in order to deliver impositions in a source format describing at least placement of content of pages of the source file and action marks for subsequent displaying of the impositions on a user interface of the document processing system and/or for subsequent processing on the at least one printer and/or an the at least one finisher. A document processing system is configured to execute the method.

Document processing system for processing a print job

A method for making a color transform for an output device is provided. The color transform represents a correspondence relation between a first and a second color space. Each of the two color spaces involves a number of color channels and the color channels of the second color space control the colorants in the output device. An excess relation for the color channels of the color space associated with the output device is established and only color points in the second color space wherefor a sum of the excess values related to the color point is lower than a predetermined limit, are included in the color transform. This enables to adapt the shape of a color gamut to a behavior of the colorants and enhances the flexibility in making a color transform for various print processes.

Method for making a color transform

A color management method, wherein a Graphics Processing Unit (GPU) is used for converting colors from a source device color space to an output device color space in accordance with predetermined color profiles of the source and output devices. The method includes the steps of storing, in the GPU, an at least three-dimensional conversion texture that specifies a color conversion table; loading input color data into the GPU; sampling the conversion texture at a position specified by the input color data, thereby to identify output color data; and outputting the output color data.

Color management method, module, and program product, and printer using said method

A method of compressing and decompressing digital data that is especially suitable for halftoned image data in which every bit represents the marking of a receiving material by ink or toner is provided. The method is lossless and balances the use of memory, the processing time, the compression factor and the cost of hardware resources. The recurrence of data in halftoned images on which the smaller data size of the compressed data is based, is caused by the use of a halftone dither matrix. Various halftone dither matrices may be used in the halftoned image. The method is adapted to employ the characteristics of a specific halftone dither matrix by applying a dynamic set of offset values, in which an offset value represents a number of words between the current word of digital data and an identical, previously processed word.

Method for compressing and decompressing digital data

A method compresses a digital continuous tone image of pixels situated on scan lines. The method includes the steps of, for a current pixel to be encoded, said current pixel having an actual pixel value, predicting a predicted pixel value based on pixel values of at least one previously processed pixel from the same image, using a fixed rule, determining a difference parameter based on a difference value of said predicted pixel value and the actual pixel value of said current pixel to be encoded, and inspecting the difference parameter for existence of an uninterrupted series of highest order bits having a value equal to zero, removing at least part of said highest order zero bits, and, if a number of bits within predetermined limits remains, generating a compression code having a predetermined fixed length, said code indicating the number of remaining bits.

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Velden, Netherlands

Maurice L M Luttmer