Oki Data Corporation

Oki Electric Industry Co., Ltd.

Nobuhito Matsushiro

Ikuo Oyake

Yasushi Kobayashi

Noriharu Fujiwara

Kazuyo Kurabayashi

Yukio Endo

Tomonori Kondo

Norihide Miyamura

Takayoshi Yoshida

Kazuyo Watanabe

Yoshihiko Yoshida

Noboru Ota

Hazime Hatanaka

Ikuo Ooyake

An image converting method includes the steps of: converting each pixel of an input image into 2-dimensional conversion chromaticity coordinate values which are obtained by projecting conversion chromaticity coordinate values obtained by converting each of said pixels by using parameters for converting in chromaticity coordinates onto a unit plane, and obtaining parameter values in which a barycenter of a color region including the 2-dimensional conversion chromaticity coordinate values are set to &#x2153;; and converting the input image by the obtained parameter values.

Image converting method and image converting apparatus

An image processing apparatus for measuring concentration of concentration patterns by optical sensors and correcting image information on the basis of a correction value obtained on the basis of measured concentration values has: a measured concentration value obtaining unit which measures the concentration in different concentration patterns by the optical sensors and obtains the measured concentration values; an estimation value obtaining unit which estimates original concentration by an independent component analysis on the basis of the obtained measured concentration values and obtains an estimation value; and a correction value obtaining unit which obtains the correction value for allowing the measured concentration value to approach the obtained estimation value. An influence of color noises is reduced, thereby correcting an image.

Image processing method, image processing apparatus, and image forming apparatus

A light source presuming apparatus includes: a candidate light source color obtaining unit which obtains candidate light source colors; a guide light source color holding unit which holds guide light source colors for guiding obtainment of parameters of a color adaptation model showing color adaptation of the sight sense from the candidate light source colors to a reference light source color; a guide parameter obtaining unit which obtains such parameters so as to be guided to the guide light source colors; an error converging unit which obtains light source colors, as correction candidate light source colors, having the relation showing the color adaptation of the sight sense with the reference light source color by using the color adaptation model shown by guide parameters, substitutes the correction candidate light source colors for the candidate light source colors, and converges errors included in the candidate light source colors; and a light source color presuming unit which presumes the correction candidate light source color of the minimum errors as a light source color of the image data.

Light source presuming method and apparatus

Parameters for mapping colors from an input system to an output system are determined by displaying a set of adjustment colors in the input system and outputting a reference color pattern in the output system. A human operator selects the reference colors most closely matching the adjustment colors. The mapping parameters are determined from the operator's selections, by table look-up or by use of a mathematical formula, for example. Accurate color mapping parameters can be generated in this way without the need for trial and error.

Image processing apparatus and method of generating color mapping parameters

A print head comprises a plurality of light emitting devices which are arranged such that the adjacent light emitting devices are stepped from each other in the rotation direction of a photosensitive member, or a plurality of light emitting devices which are disposed linearly such that the light emitting devices emit light at different timings each other by employing a delay mechanism. Consequently, it is possible to provide the output pattern capable of directing the human eyes in two dimensions so as to reduce the visible difference in the image density.

Print head and image forming apparatus

A method for obtaining spectral sensitivity characteristics of a color image input device such as a color scanner or a like is provided. The most optimum spectral sensitivity characteristics of the color image input device can be obtained by amending CIE XYZ color matching functions so that X, Y and Z values of two color stimuli perceived to be the same in color by observation under a specific illuminant are made equal and by performing linear transformation on the amended color matching function.

Method of deriving spectral sensitivity characteristics for color image inputting device and apparatus for same

A method of image transforming is proposed. The method includes generating from an original image having a plurality of original picture elements, a new picture element from the plurality of original picture elements that are neighboring, and forming a first transformation image by arranging the new picture element among the plurality of original picture elements; dividing the original image into a plurality of first regions each having picture elements, searching respective second regions each having picture elements corresponding to the picture elements in the first region, and forming a second transformation image by transforming the picture elements in the first region into the picture elements in the second region; comparing values of respective picture elements in respective corresponding regions of the first transformation image and the second transformation image; and on the basis of the comparison result, deciding to output one of the regions in the first transformation image and the second transformation image.

Method and device of image transform

When image data are processed to generate pseudo-tone patterns, a predetermined threshold is modified according to at least two periodic functions with different spatial periods. The picture elements are compared with the modified threshold, and the comparison results are used to generate an output image. The periodic threshold modifications cause dots to appear preferentially in regular patterns, thereby reducing dot noise, and providing improved control over the overlaying of dot patterns in different color planes in a color image.

Image-processing method and apparatus generating pseudo-tone patterns with improved regularity

A color correcting apparatus corrects color data according to second ambient light so that an output device outputting a color based on the color data calibrated in first specified ambient light can output almost the same color in the second light. The apparatus comprises a storing section used to store several main component data each representing a different component of light, which are combined to reproduce the second light, an input section used to input several weighing coefficients to assign weight to each of the several pieces of component data when they are combined and a correcting section used to correct color data based on correction parameters obtained using the several pieces of component data stored in the storing section and using the several weighing coefficients input through the input section.

Color correcting apparatus

An image is coded by counting runs of non-background picture elements, and counting consecutive scanning lines having only background picture elements. Consecutive scanning lines of this type are coded as a single command and value, giving the number of scanning lines. Consecutive scanning lines having identical numbers of runs of non-background picture elements are coded as another single command and value, giving the run count, followed by run information describing each run. Sparse images, consisting mostly of background area, can be coded efficiently in this way.

Method and apparatus for efficiently coding and decoding sparse images

An image is divided into blocks and coded by matching each block with a pattern having either a single region, or two or more regions defined by internal edges. The coded value of the block includes a pattern identifier, and a single pixel value for each region in the matching pattern. The coded image is decoded by constructing blocks divided into regions according to the pattern identifiers, and filling each region with the given single pixel value. The decoded blocks may be the same size as the blocks in the original image, or smaller, in which case the decoded image is reduced, or larger, in which case the decoded image is enlarged.

Image coding and decoding methods, image coder, and image decoder

A multi-level input image is divided into blocks, each of which is quantized to a bi-level output block. A single quantization error value is calculated for each block, and distributed over neighboring blocks that have not yet been processed. Blocks containing abrupt changes in image content are preferably converted by comparing each picture element individually with a threshold value. Blocks not containing abrupt changes are preferably quantized by comparing the average value of the block with multiple threshold values to determine a multi-level block output value, from which a predetermined pattern of bi-level picture elements is generated.

Image processing method and apparatus employing block error diffusion

When the corresponding position of each pixel in stereo video pair is searched, a fixed pixel is set in one side video and the corresponding pixel is set in the other side video. Then, a window is set around the fixed pixel in one side video and a same size window is set around the corresponding pixel in the other side video. Selectable and plural kinds of window size are prepared at that moment. Pixel values are compared with each other respectively. The MDL standard value is adopted as for an evaluation standard. In the comparison, the smaller the MDL standard value of the window size, the more suitable the window size. All pixel values in the window are used for parameters to calculate the MDL standard value. The MDL standard value contains the value which is equivalent to error quantity in case of comparing each pixel in the window, it also indicates resemblance of the video picture in the windows. The corresponding pixel having the minimum MDL standard value is supposed to be the corresponding position of the fixed pixel. In this way, searching the corresponding point can be performed based on the comparison results in the most suitable model.

Video signal processing and apparatus therefor

An image is divided into blocks of N consecutive pixels, and each block is coded with reference to M reference pixels, where M and N are integers greater than one. Different patterns of N pixels are obtained from the M reference pixels. If one of these patterns matches the N consecutive pixels sufficiently closely, that block of N consecutive pixels is coded as a flag and a pattern code. When the coded data are decoded, the flags identify blocks that were coded in this way, and these blocks are decoded by copying already-decoded data identified by the pattern codes.

Coding and decoding methods and apparatus for compressing and expanding

An input data sequence is divided into fixed-length source segments, and each source segment is predicted from preceding data. The data are coded as a sequence of coded segments, each designating a non-negative number of correctly predicted segments and a non-negative number of literal segments. The literal segments are inserted into the coded data among the coded segments. The coded data are decoded by decoding each coded segment, predicting the designated number of correctly predicted segments from previously decoded data, and copying the literal segments. The length of the coded segments may vary according to the number of consecutive correctly predicted segments. The prediction rule, or the original data, may be modified under certain conditions, in order to increase the predictability of the source segments.

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Tokyo, Japan

Nobuhito Matsushiro