摘要:
A color marking device including a control system for calibration of the device based upon dynamic color balance control of an output image. The system comprises a front end converter for converting an input signal representative of a target image comprising a preselected color into a device-dependent control signal in accordance with a device TRC, a color marking device for outputting an output image in response to the control signal, a sensor for measuring a parameter from the output image representative of a color of the output image, and, a point-wise controller for comparing the parameter with a corresponding parameter from the target image and constructing adjusted controlled points for the device TRC when the measured parameter and the corresponding parameter vary by a preselected value, a color balance controller for constructing an adjusted device TRC from the controlled points, whereby subsequently generated output images are output with the adjusted device TRC and, more accurately represent target input images.
摘要:
An apparatus and method that provide consistent output across a plurality of different hard copy output devices which may be included in a system comprising an image data source and a hard copy output device. The image data source supplies image data to a printable image data adjusting apparatus. The image data supplied may be in a device-dependent color space or a device-independent color space. If the image data is in a device-dependent color space, the printable image data adjusting apparatus first converts the image data into device-independent image data and stores it in memory as target image data. If the image data is already device-independent image data, the image data are simply stored in the memory of the printable image data adjusting apparatus as target image data. The printable image data adjusting apparatus then uses the target image data to generate printable image data. The hard copy output device uses the printable image data to generate a hard copy image. The hard copy image is then passed within the optical field of a sensor that detects device-independent image data values of the hard copy image. The detected device-independent image data values are then compared against the target image data to generate color adjustment factors. The color adjustment factors are then used to produce a hard copy image having detected device-independent image data values that more closely represent the target image data. The apparatus and method may be implemented in real-time with or without human intervention.
摘要:
A halftone cell is composed of a plurality of pixel groupings predefined to correspond to optimal tone level gradations. Selected output pixel groupings vary in number, and in shape of subpixels used from other pixel groupings, in order that successive input levels correspond to successive halftone cells defining substantially equal changes in a measured darkness value. Tone level gradations are optimized by purposeful correlation of input levels to output levels, especially where the number of output levels exceeds the number of input levels. During optimization, a calibration sample is produced by the image output device and calibration elements are empirically measured. Darkness change between successive levels is calculated and compared. Where the percentage of darkness change exceeds a desired amount, additional calibration elements are produced until the change calculated between successive levels is substantially the same. Successive input levels are associated with successive output levels such that a change between any adjacent input levels produces a change in darkness in the desired amount. The correlation is stored in a look up table for use during operation of the image output device.
摘要:
A system and method for printer control and color balance calibration. The system and method address the image quality problems of print engine instability, low quality of color balance and contouring from the calibration. The method includes defining combinations of colorants, such as inks or toners that will be used to print images, defining a desired response for the combinations that are to be used and, in real time, iteratively printing CMY halftone color patches, measuring the printed patches via an in situ sensor and iteratively performing color-balance calibration based on the measurements, accumulating corrections until the measurements are within a predetermined proximity of the desired response. The calibration is performed on the halftones while they are in a high quantization resolution form.
摘要:
Disclosed is a method for processing raster image data and determining via a reference device (e.g., LUT), an amount of marking medium (toner, ink) to be used for printing a document. Then billing costs based on the amount of medium is determined. In particular, a calibration method may be performed on an apparatus to determine the amounts of medium used for that particular apparatus. The calibration method includes printing pages with test patches for a plurality of colors at a particular dot value (or density), and weighing similar printed test pages so that the amount of medium used to print colors at particular dot values is determined by subtracting a weight of the pages before printing from the weight of the printed test pages. The change in weight (or mass) of the medium is used to populate the reference device for that apparatus.
摘要:
This disclosure provides methods, apparatus and systems to generate vector halftone data for rendering an image on an image output device. According to one aspect, a method generates vector halftone data as a function of contone pixel data for a given colorant at its nominal resolution and contone pixel data for the other colorants at a relatively lower resolution.
摘要:
Vector halftoning and error diffusion are combined to provide a quantization method that yields high quality rendered images while demanding fewer system resources. For instance, the method is tolerant of resolution reductions in secondary or auxiliary channels to the vector halftoning process. Accordingly, these secondary pixel data channels can be sub-sampled and/or bit-depth reduced for transmission bandwidth conservation and/or reduction in data storage requirements. Restoring the resolution of the low resolution channels provides estimated image data to arrange or align with high resolution target channel data for the vector halftoning process. Error from marking decisions generated by the vector halftoning process is diffused to neighboring unprocessed pixels. The method also allows for the use of a small vector halftone threshold array while providing quantized images with fine texture and wide color gamuts. In some embodiments error diffusion is distributed according to vector error diffusion.
摘要:
Halftone generating methods and systems convert continuous tone anti-aliased image data to halftone image data using halftoning techniques that efficiently use memory resources. One of a plurality of Holladay counters is selected and the address bits from the selected Holladay counter are output to a look-up table that efficiently stores various halftone screens. Halftone image data is then output. If necessary, the halftone image data is unpacked and replicated as required depending on the resolution requirements of the halftone screen.
摘要:
The present invention is a super-scalar method and apparatus for the generation of halftone dot patterns in an image processing system. The super-scalar design employs at least one block of memory for the storage of at least one predetermined halftone dot pattern across a plurality of unique locations therein, and a sequencer for producing an index into said memory as a function of the position of the pixel along a scan line and the halftone dot characteristics. Also included is addressing circuitry for memory access control, to combine the index produced by said sequencer and a pixel value for the pixel to produce a memory address, the memory address being thereby employed to access one of said locations in memory and to cause said memory to output a signal representative of a portion of the halftone dot pattern stored at the unique addressed location.
摘要:
According to an aspect of the disclosure, a printing system is provided comprising a plurality of resources including idle and non-idle resources having a at least one image marking engine. The plurality of resources includes a page parallel RIP system wherein the RIP system supports configurable sized print chunks. The RIP system adaptively adjusts the size of the chunks according to the busyness of receiving RIP nodes.