摘要:
An apparatus for correcting beam-to-beam spacing error on an image plane of a photoreceptor includes a controller which generates beam-to-beam spacing error corrections signals, a plurality of optical elements, each of which is adjustable and responsive to beam-to-beam spacing error correction signal and a gray level measurement device. The controller performs the beam-to-beam spacing error correction analysis, determining whether or not a correction is necessary, and if so, which optical element to adjust and the magnitude of adjustment. Enhanced toner area coverage sensors are used to detect the gray level of a toned area of raster scan line patterns at various locations across the photoreceptor image plane. By repeatedly evaluating the beam-to-beam spacing error during operation, the apparatus of the invention is able to correct beam-to-beam spacing errors that may develop during operation and does not permit residual errors to persist even after an initial correction has been implemented.
摘要:
Systems and methods for template matching of multicolored images provide an image conversion process that respectively views two, three or four input color planes through an input observation window. Single plane vectors are obtained that represent the color planes. The obtained single plane vectors are combined into a multi-plane vector that may be used in a look-up table for descreening or resolution enhancement, for example. Various interactions between color planes may be taken into account to provide optimum color space conversion. Additional information obtained by using the multi-plane vector allow performance of image processes with optimized accurate color values.
摘要:
The methods and apparatus of this invention model and reconstruct binarized images. A grayscale image is modeled using a template matching approach. Each binarized grayscale image value is characterized by a unique set of templates which are rotations of each other. The set of templates allows construction of a look-up table between patterns and grayscale values. The look-up table is provided with a limited number of entries. As a result, the number of entries in the look-up table is reduced. The look-up table thus obtained is used for reconstructing the original grayscale image from the binarized image. The generated image quality is good in comparison with conventional methods. The process may be applied to various halftoning processes including error-diffusion processes.
摘要:
The present invention is a method for antialiased rendering (AAR) of an image. First, tagging methods for identifying antialiased pixels were described, the methods being employed separately or in concert with one another. After identifying AAR pixels, a fill order is determined and applied using a fill order algorithm that preferably employs a pixel window that is a subset of the larger window employed for pixel identification.
摘要:
The present invention is a method for efficiently processing an image to detect antialiased pixels using reduced buffering memory. The method stores, in a scanline buffer memory, a predefined number of scanlines of data including data for a target pixel position and, in a tag buffer memory, a plurality of binary antialiasing tags, including at least a previously estimated tag for the target pixel position. Then using the stored pixel data and previously estimated tag, an antialiasing tag for the target pixel position is generated.
摘要:
The present invention is a method and apparatus for logic based resolution conversion and enhancement of digital images. The invention employs a selectively controllable architecture wherein a plurality of input resolutions can be converted to a common output resolution. The system has particular use in highlight color systems, wherein the highlight color data may be processed separately for each color plane, using the present invention, and then recombined to produce enhanced highlight color output. Moreover, the hardware preferably employs an interlocked area mapping technique to produce the resolution converted bit planes of digital image data.
摘要:
The present invention is a method and apparatus for improving the appearance of printed documents, and more specifically, to the use of a template matching process to enhance the fast-scan resolution of digital images while maintaining raster resolution for printing. The present invention uses multiple-bit per pixel, statistically generated templates, implemented using look-up tables, to improve document appearance by converting from a single-bit per pixel to N-bits per pixel, while preserving raster resolution of the printed output. The resulting N-bit per pixel image signals may be utilized to control a scanning beam where the beam varies in intensity and duration according to the pulses used to control it.
摘要:
A method and apparatus for automating the design of morphological or template-based filters for print quality enhancement. A plurality of different phase, but same resolution, subsampled images are generated from training documents. Statistical data derived therefrom is then employed in an automated process to generate filters. The filters may be used for resolution enhancement and/or conversion of bitmap images. Furthermore, the statistical data is used to produce filters that are intended to not only optimize image structure, but image density as well.
摘要:
A hybrid halftone cell selection method enables selection of gray levels in halftone printing algorithms to minimize the effects of noise resulting in nonuniformities, such as, for example, halftone banding. The method requires selection of hybrid halftone cells possessing structures wherein the total number of gray pixels are limited. The number of gray pixels having any given intermediate reflectance level in any halftone cell is also limited. The cell selection method thus reduces the number of TRC gray steps to some minimum required number by eliminating the most noise sensitive cells (i.e. those cells having the highest percentage of gray level pixels). The intermediate reflectance values of the gray pixels in the selected cells are then selected to produce uniform gray steps and reduce variability in the TRC.
摘要:
The present invention is a method for automating the design of pattern matching templates used to implement a print quality enhancement filter that preserves image density More particularly, the method is directed to the use of a representative set of page description language decomposed or scanned training documents, and statistical data derived therefrom, in an automated process that generates one or more sets of template-pattern pairs that are used as filters for resolution enhancement and/or conversion of bitmap images.