Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Hitoshi Yoneda

Hiroki Kanno

Hironobu Machida

Koji Tanimoto

Takefumi Nosaki

Hajime Nakamura

Haruyoshi Hasegawa

Hidekazu Sekizawa

Naofumi Yamamoto

Ryosuke Hiramatsu

Tutomu Saito

Akito Iwamoto

Tadanobu Kamiyama

The video coding system picks up the whole image of postal matter, inputs the picked image to a character/code & image reader to read a user code on the postal matter, prints bar code information corresponding to the read result on the postal matter, and sorts the postal matter according to the bar code information. In this system, a display device displays the whole image of postal matter from which the user code cannot be read, and user code candidate characters, together with a user code input area for inputting the user code, an image of a specific user code location, and images of a plurality of user code candidate areas. An operator inputs the user code, which the character/code & image reader failed to read, in the user code input area while visually checking the displayed whole image and the images of the user code candidate areas. The input user code is stored in a memory.

Video coding system

An apparatus for printing an image which is stored on an optical disk is read by a scanner. A plurality of images read out from the optical disk are edited to form an abstract image on the basis of a predetermined unit (e.g., one page), and code data (i.e., retrieval data) is added to the abstract image. The resultant image, including both the abstract image and the code data, is printed on a sheet. The code data is extracted from the printed image, and desired images are retrieved from the optical disk on the basis of the code data.

Image forming apparatus with filing function which can store image data

This invention utilizes the fact that a maximum density difference of pixels in a window within a predetermined range including a pixel of interest is large for a character region, and is small for a photograph region. A maximum density difference of an image within the predetermined region is calculated. A quantization error of pixels around the pixel of interest is calculated, and a correction amount is then calculated by proportionally distributing the quantization error in accordance with a feature amount calculated by a feature amount calculator. The correction amount is added to an image signal of the pixel of interest to form a compensation image signal, and the compensation image signal is quantized.

Image processing apparatus with improved dithering scheme

An image processing apparatus having a first conversion section for converting image data of a target pixel in a multi-color image as an object to be processed into first color data corresponding to colors of the image data, a second conversion section for converting the first color data converted by the first conversion section into binary data, a first calculation section for calculating second color data having the same colors as those of the image data on the basis of a plurality of the binary data converted by the second conversion section, a second calculation section for calculating color errors between the image data and the second color data calculated by the first calculation section, a third calculation section for calculating weighting errors by multiplying the color errors calculated by the second calculation section with predetermined weighting coefficients, a storage section for storing the weighting errors calculated by the third calculation section, and a correction section for correcting the image data of the target pixel according to the weighting errors stored in the storage section.

Image processing apparatus and image processing method for reproducing a

An image forming apparatus capable of magnifying a target image to any desired magnification, includes functions for detecting the maximum and minimum densities from limited image information, including a data piece representing a picture element of the target image, functions for determining from the difference between the maximum and minimum densities detected by the detection means, whether the picture element is in a photographic region or a character region, functions for determining a picture element density appropriate for magnifying the target image from the density of the target picture element and that of a picture element close to the target picture element, and functions for outputting the picture element density determined by the density-determining means, in accordance with whether the target picture element is in a photographic region or a character region.

Image processing apparatus for variably magnifying image and controlling

This invention utilizes the fact that 'a maximum density difference in a window within a predetermined range including a pixel of interest is large for a character region, and is small for a photograph region.' A maximum density difference of an image within a predetermined range is calculated as a feature amount. A quantization error of pixels around a pixel of interest is calculated, and then, a correction amount is calculated by proportionally distributing the quantization error in accordance with the feature amount calculated by a feature amount calculator. The correction amount is added to an image signal of the pixel of interest to form a compensation image signal, and the compensation image signal is quantized.

An extractor extracts, from image data to be binarized, a feature amount of a target pixel including at least a maximum density difference among pixels in a local region including the target pixel. A predictor predicts an image type of the target pixel in accordance with a minimum density value among the pixels in the local region. A selector selects one of the feature amount of the target pixel from the extractor and a feature amount obtained by adding the feature amount of the target pixel to feature data of neighboring pixels in accordance with the image type predicted by the predictor. A discriminator discriminates the image type of the target pixel in accordance with the feature amount selected by the selector. A weighting section weights the discrimination result from the discriminator with respect to the neighboring pixels of a predetermined range preceding the target pixel in accordance with distances from the target pixel to the neighboring pixels so as to generate feature data of the neighboring pixels selectively used by the selector. A determinator adaptively determines a threshold value for binarizing the image data in accordance with the discrimination result. A binarizing section binarizes the image data in units of target pixels by using the threshold value determined by the determinator.

Image data processing system with adaptive binary quantization

An image processing apparatus including an input circuit for receiving image data, a binarizing unit for binarizing a subject pixel of the image data supplied from the input circuit, an error detector for detecting an error between a binarized image data obtained by the binarizing unit and the image data supplied from the input circuit, an error diffusing circuit for diffusing the error on other image data associated with other pixels around the subject pixel, a compensating unit for compensating the image data of the subject pixel by using a compensation data which is caused by a previous error diffusion of the error diffusing circuit, a circuit for detecting an image density of the image data for a prescribed image area surrounding the subject pixel and a controller for controlling the compensating unit in response to the image density detected by the image density detecting circuit.

Image processing apparatus

A feature-analyzing section determines whether a given picture element included in image information supplied from a line buffer represents a character portion or a photograph portion. In accordance with the determination made by the feature-analyzing section, a threshold value selection section selects either a threshold value calculated by a first threshold value calculation section, and to be used in relation to charcter portion, or a threshold value calculated by a second threshold value calculation section, and to be used in relation to photograph portion. By using the threshold value selected by the threshold value selection section, a binary-encoding section binary-encodes image information which is supplied thereto through a delay circuit. On the basis of the determination made by the feature-analyzing section, a determination section determines whether or not the given picture element represents a bold character portion. If the determination section determines that the given picture element represents a bold character portion, a selection section then selects a predetermined value supplied from a value generation section, in place of an output of the binary-encoding section.

Image binarization apparatus

A image processing apparatus includes a dither processor, which converts an electrical signal representing a continuous-tone input image into a binary image singal by a dither method using a dither matrix. The binary image signal is stored in a memory, and supplied to a pixel-density conversion processor, which converts a pixel density of the binary image signal at a predetermined ratio, and generates a converted image with the pixel coordinates as defined by the conversion ratio. A pixel coordinate calculator calculates a coordinate position of each pixel of the converted image in the binary image, and selects a fiducial pixel. A reference pixel selector defines a window area on the binary image containing the fiducial pixel and corresponding in size to the dither matrix size, and extracts reference picture elements in the window area. A calculator calculates an average image-density of the reference picture elements and generates density data, which is binarized by a second dither processor by using a second dither matrix.

Method of and apparatus for changing the pixel density of a binary image

A method and apparatus of electrophotography used for a printer or a copying machine, wherein a toner having no photoconductivity is applied on a surface of a photoconductive layer of a photoreceptor consisting of a transparent conductive layer and the photoconductive layer which are sequentially formed on a transparent substrate. The photoconductive layer is exposed from a side of the transparent substrate. Toner particles on an exposed region of the photoconductive layer are transferred to toner-receiving paper opposite the photoconductive layer so as to form a toner image. A process for developing a latent image can be omitted. In addition, a special toner such as a photoconductive toner having low sensitivity is not used, thereby forming a high-quality image.

Method and apparatus of electrophotography

A color copying apparatus includes a color image sensor, an image information signal processing unit, and a color printer. The apparatus converts the three color component signals from the color image sensor into a luminance signal component and color difference signal components. At least one of the luminance signal component and the color difference signal components is subject to a nonlinear conversion. For density conversion between an input image and an output image, the luminance signal component is subject to a nonlinear conversion in a nonlinear conversion circuit.

Color image copying apparatus

The invention provides an apparatus for forming a multicolor image, comprising a photoconductive drum which comprises a conductive substrate, and a photoconductive layer and a transparent insulating layer, a first charger to perform primary charging, a first light source to expose the entire surface of the photoconductive drum, a second charger to secondarily charge the transparent insulating layer at the second polarity, a second light source to emit light, an amount of which is controlled to have two levels in accordance with first and second color image data, a first developing unit to develop the first color image, a third light source to perform a second entire-surface exposure of the photoconductive drum, and a second developing unit to develop the second color image.

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Kawasaki, Japan

Hitoshi Yoneda