Toshiba Tec Kabushiki Kaisha

Kabushiki Kaisha Toshiba

Kabushiki Kaisha Tec

Nobuhiko Nakahara

Hiroki Umezawa

Masaaki Yasunaga

Atsushi Kubota

Sunao Tabata

Tomonori Ikumi

Kazunori Murakami

Nobuyuki Kato

Disclosed is a method of generating a screen for an image processing apparatus, which reproduces a multi-gradation image in one pixel using a PWM technique for controlling a pulse width and reference position data. The method includes inputting image data with a first resolution, virtually increasing the first resolution to a second resolution using the reference position data, and generating a screen with the second resolution with respect to the image data using two reference vectors based on the reference position data.

Screen generating apparatus, screen generating method, and image processing apparatus

An image processing apparatus includes a contour pixel extraction unit configured to extract a contour pixel component from a bit plane. The bit plane is a set of bits, the number of which is equal to the number of pixels, and each of which is 1 bit of a plurality of bits representing an intensity of each of pixels. Also provided is a connectedness detection unit configured to detect equivalent bits adjacent to each other in a window including a bit corresponding to a target pixel on the bit plane. Also provided is a filter unit configured to reduce an intensity of the target pixel by a reduction amount determined in accordance with the contour pixel component extracted by the contour pixel extraction unit and the equivalent bits adjacent to each other detected by the connectedness detection unit.

Image processing and formation with line thininng by reducing intensity of target pixel based on extracted contour pixel and area connectedness information

An image forming apparatus includes a laser array in which n light emitting sources are arrayed, an image-input converting unit configured to create, for each of channels of the laser array, a recording pattern for executing PWC from input image data and extract recording patterns of an nth channel and a first channel of the next scanning of the laser array, an overlapping control unit configured to calculate the width of laser pulses in the same position in a main scanning direction as overlapping width, a data correcting unit configured to reduce laser pulse width by a reduction amount corresponding to the calculated overlapping width and correct the laser pulse width, and a laser driver configured to control the intensity of laser beams in the respective channels of the laser array according to the recording patterns after the correction.

Image forming apparatus, image forming method and image processing apparatus

An image processing apparatus includes an image input device to convert image data into uncompressed data of CMYK, a gradation processing device to perform a gradation process on the uncompressed data to generate a halftone image, a rearrangement determination device to determine necessity of rearrangement of pixels of the halftone image, a selector to select an output destination based on a rearrangement necessity determination result, a rearrangement device to rearrange the pixels by using a threshold table used at a time of execution of the gradation process of the halftone image, and a coding device to output data obtained by coding data of the halftone image. According to the image processing device, coding efficiency can be improved more than in the related art while a harmful effect (reduction in code amount) due to the rearrangement process is suppressed.

Image processing apparatus and image processing method

A halftoning process section in an image processing apparatus includes a process switching section that switches a process of a signal from a color conversion process section. The process switching section executes switching in accordance with input tag data. In the case of a text, a text halftoning process section executes a halftoning process. In the case of graphics, a bit number increasing section increases a bit number for graphics, and a graphics halftoning process section executes a halftoning process. In the case of a photo, a bit number increasing section increases a bit number for a photo, and a photo halftoning process section executes a halftoning process.

Image processing apparatus

An image data decoding apparatus decoded synthesized-compressed data in which image data with a plurality of resolutions is compressed in block units by different compression systems, respectively, and each compressed data is synthesized to a single piece of compressed data. The image data decoding apparatus comprises a separating section-for separating the synthesized-compressed data to compressed data with every resolution, decoding sections--for decoding separated and compressed data with a first resolution to obtain first high-resolution data and also decoding compressed data with a second resolution obtained from the separating section to obtain first low-resolution data, a conversion section-for converting the first low-resolution data into second high-resolution data, and an image synthesis section-for synthesizing the first and the second high-resolution data to obtain a decoded image signal.

Image data decoding apparatus and method

In the present invention, in an image output apparatus having a specific resolution, a micro normal random number or a blue noise is synthesized in threshold matrix having a plurality of half-tone centers, having an equal interval between half-tone centers in most vicinity, and having lattice elements addressable at a rational tangent angle, wherein a growth order among half-tones is defined in a defined periodic order.

Method and apparatus for processing of half-tone image

A halftone processing section halftone-processes input image data using a plurality of dither threshold planes. An image output section having different output position accuracies between a main scan direction and a sub-scan direction outputs an image corresponding to halftone-processed image data. Each of the dither threshold planes consists of a plurality of the same unit threshold matrixes. In the unit threshold matrix, a relatively medium to high threshold array in a predetermined threshold range corresponding to the entire tone range of the input image data is an aperiodic array and an anisotropic array with neighboring thresholds having close values, in a direction coincident with a scan direction, in which the output position accuracy of the image output means is low. With this configuration, the image output section outputs an image having serial medium and high tone dots in the scan direction.

Image processor and color image processor

Halftone processing section carries out a halftone processing using a dither threshold plane on which thresholds in a predetermined threshold range corresponding to the tone range of input image data are arranged, and provides halftone-processed image data. Image output section has intrinsic, basic tone characteristics and outputs an image corresponding to the halftone-processed image data provided from the halftone processing section. The dither threshold plane consists of a plurality of same unit threshold matrixes and each of the unit threshold matrix consists of a plurality of sub-matrixes. An array of relatively low thresholds in the predetermined threshold range is equal among the plural sub-matrixes, and relatively medium thresholds and high thresholds in the predetermined threshold range are arranged periodically to extend over series of sub-matrixes.

The invention provided an image processing method having the steps of, storing a plurality of multi-level dither threshold value arrangements employed for a multi-level dither process, discriminating a given first gradation image data expressing one pixel by a first bit number into an image field emphasizing a resolution and an image field emphasizing a gradation, selecting an optimum multi-level dither threshold value arrangement from a plurality of multi-level dither threshold value arrangements on the basis of a discrimination result by the discriminating step, and converting the gradation image data into a second gradation image data expressing one pixel by a second bit number less than the first bit number according to a multi-level dither process on the basis of the selected optimum multi-level dither threshold value arrangement. Accordingly, it is possible to perform a multi-level dither process which establish both of a resolution in a character/line image field and a gradation in a photo image field.

Image processing method according to sort of image and image processing apparatus

In a multilevel error diffusion process, an input image signal Din with tones and an image correction signal Ecd are added together to produce a corrected image signal Dinc, which in turn is converted into an eight-level image signal to provide an output image signal Dout with eight tones. To convert the input image signal into the output image signal, there are provided a plurality of conversion tables and a switching means for selectively switching the conversion tables at random. The conversion tables are switched with each pixel in the corrected image signal.

Image processing method and device and image formation device

In case of subjecting input graduation image data of 8 bits per pixel to multilevel dither processing, to convert them into image data having gradients of 3 bits per pixel on the basis of dither threshold planes, in a combination of threshold arrays extending over the plural dither threshold planes, dither thresholds for raising spatial fre0 quency, as shown in FIG. 8A, are arranged in low density areas of the input graduation image data, and dither thresholds for making spatial frequency lower than that in the low density areas, as shown in FIG. 8C, are arranged in half tone areas and high density areas of the input graduation image data.

Image processing method and printer

Dot width data of a plurality patterns each corresponding to a recording range in one scanning operation are stored in a memory in advance. Each dot width data required to correct an f-.theta. error is used to determine each dot width in one scanning operation. In accordance with the operation of an address counter, a bus switching circuit selectively reads out dot width data of a pattern different from a preceding pattern from the memory for each scanning operation, and outputs the data to a latch circuit. A programmable counter determines each dot width of image data on the basis of the dot width data from the latch circuit. A laser diode driver ON/OFF-controls a laser beam from a laser diode on the basis of the image data from the programmable counter.

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Susono, Japan

Nobuhiko Nakahara