Fuji Xerox Co., Ltd.

Mitsubishi Denki Kabushiki Kaisha

Fuji Xerox Corporation

Koh Kamizawa

Yutaka Koshi

Shunichi Kimura

Tokumichi Murakami

Setsu Kunitake

Taro Yokose

Kazuhiro Suzuki

Naoto Kinjo

Hideo Ohira

Masatoshi Kameyama

Akihiro Andoh

Takanori Hisanaga

Yoshiaki Katoh

Atsushi Itoh

Fumiyoshi Kawase

Shinji Shishido

Katsuya Mitsutake

Kohtaro Asai

Takahiro Fukuhara

Yuri Hasegawa

Takashi Matsumoto

Kazuhiro Matsuzaki

Yasutoshi Maeda

Takao Wakabayashi

Yuji Kozawa

Masami Nishida

Osamu Nakamura

Masanori Sekino

Kenichi Kawauchi

Fujio Ihara

Toshiaki Yoshinari

Ichiro Yamashita

Takeshi Chiba

Kouichi Yoshimura

Ken Umezawa

Toshi Minami

Eizo Yamazaki

Naoto Kinjoh

Kohji Ogura

Shuichi Kimura

Shun-ichi Kimura

Takahiko Hayano

An index signal and a delta signal are generated from an input pixel value, and then, inputted to an input buffer by every predetermined pixel to be processed. A controlling unit compares the index signal in the input buffer with a tag (index signal) in a coefficient cache. When they coinside with each other, the controlling unit reads out the corresponding coefficient from the coefficient cache and supplies the same to an interpolating unit. The interpolating unit simultaneously receives the delta signal and supplies the keeping color data to an output buffer. Thereafter, the interpolating unit accesses to the coefficient storing memory by using an index signal that does not coinside with either one of cache-tag (index signal) to obtain a coefficient, and similarly, interpolatively generates color data. Data of converted color is outputted from the output buffer in the order of inputting the pixel. A color converting device of the present invention can perform a color conversion with high precision without increasing a reading-out band of a coefficient table for a color conversion.

Color converting device

A data transmission control information acquisition section generates data transmission control information based on control information exchanged between applications of a data transmitter and a data receiver before data transmission is started. A data transfer control section determines a bandwidth to be used by the data transmission, transmission start time, etc. in a shared transmission medium in a unified manner based on the data transmission control information and current bandwidth use conditions, and transmits the thus-determined information to the data transmitter. The data transmitter transmits data to the data receiver via the transmission medium under unified management.

Method and system for data transmission accordance with the form of the data transmission based on control information exchanged between applications of a data transmitter and a data receiver before data transmission is started

An image analysis device and method that have a mechanism for exactly predicting image quality determining factors and determine a coding parameter for an input image by combining plural different image quality determining factors, which does not deteriorate the image quality of the input image and raises the compression ratio as high as possible. In the image analysis device, an image extraction unit,extracts an image area to be analyzed from an input image,. The extracted image area,is input to plural physical quantity calculating units,. Each physical quantity calculating unit,calculates a physical quantity,independently of others and each of obtained physical quantities,is input to plural image quality determining factor calculating units,. On receiving the plural physical quantities,, each of the image quality determining factor calculating units,calculates an image quality determining factor,. A coding parameter calculating unit,calculates a coding parameter based on the plural image quality determining factors,output from the plural image quality determining factor calculating units

Image analysis method and device

A data transfer apparatus and method uses recovery-type congestion control and avoidance-type congestion control. A bandwidth determination unit determines a requested bandwidth for a congestion avoidance-type data transfer in accordance with control information communicated between applications prior to the congestion avoidance-type data transfer. A bandwidth estimation unit estimates a bandwidth having been used by a congestion recovery-type data transfer in accordance with the control information communicated between applications prior to the congestion recovery-type data transfer. A management information memory stores information data of all the congestion avoidance-type data transfers and congestion recovery-type data transfers that use the bandwidth at a particular moment (i.e., simultaneously). A bandwidth allocation unit determines whether a newly requested congestion avoidance-type data transfer can be performed in accordance with an unused bandwidth and a bandwidth requested by the new data transfer, and allocates a certain amount of bandwidth to the new congestion avoidance-type data transfer. A data transfer instruction unit instructs an application to perform new data transfer.

Data transfer apparatus and method using congestion recovery-type and

A data transmission apparatus having a storage device for storing at least one structure data piece of a data processing device in a receiving data processing apparatus, a computation device for computing a transmission error detection code from the structure data stored in the storage device and a device for attaching the transmission error detection code computed by the computation device to the structure data stored in the storage device. The data transmission apparatus further includes a transmitter for transmitting the structure data to which the transmission error detection code is attached to a receiving apparatus, a receiver for receiving a retransmission request for each structure data piece returned from the receiving apparatus when a transmission error is detected based on the transmission error detection code and structure data transmitted by the transmitter, and a device for responding to the restransmission request for each structure data piece received by the reception means by retransmitting the corresponding structure data piece to the receiving apparatus.

Data transmission apparatus and method

An image quality control apparatus having an image divider, a converter, an image analyzer, an image output property circuit, a quantization method selector, a quantizer and a coder. The image divider divides an input image into a plurality of divided images including a predetermined number of picture elements. The converter converts the divided images into converted coefficients. Then, the image analyzer determines a property of the divided images which is output by the image output property output circuit. A quantization selector selects a quantization method in response to the divided image property that was found by the image analyzer and the image output property output circuit. The quantizer quantizes the conversion coefficients found by the converter in accordance with the quantization methods selected by the quantization selector. A coder then codes the conversion coefficients quantized by the quantizer.

Image quality prediction apparatus and method, and image quality control

A plurality of reference pixel extracting means check their corresponding reference pixel ranges and pixel values in predetermined auxiliary regions. Reference pixel range selecting means selects a reference pixel range based on the checked pixel values. When the number of types of pixel values for an input image is found to be locally low in the selected reference pixel range, the number of reference pixels is increased. On the other hand, when the number of types of the pixel values for the input image is found to be locally large, the number of reference pixels is decreased. As a result, states can be generated by a Markov model image encoding system capable of improving encoding efficiency without increasing the number of the states sharply. Owing to the above construction, even when the number of tones for the input image is high upon Markov model image encoding, the number of reference pixels can be increased without abruptly increasing the number of states later on to improve compression efficiency.

Markov model image encoding device and method

The memory capacity required for temporarily holding image data with respect to a printer is reduced, and loads involved in supplying image data, such as decoding and conversion processes, are dispersed and reduced. The apparatus divides image data in parallel with a main scanning direction by an image divider, stores the divided data in image data memory, and supplies the divided image data to image data temporary memory by an image data supply to perform a decoding process. In order to provide a matching with a process speed, the image data temporary memory temporarily retains the divided image data, and a printer prints an image on a sheet of paper on the basis of the divided image data stored in the image data temporary memory. A predictor predicts a supply process time by way of image data supply, and an image data supply control causes the image data supply to start the supply process of the divided image data at a time preceding the time for the start of the print process by the printer according to the time predicted.

Image forming apparatus

An image information coding apparatus includes a block generator for dividing image information into pixel blocks, each of which consists of a predetermined number of pixels. A block selector selects a pixel block in a position different from that of a pixel block selected in a preceding block line in a main scanning direction from the pixel blocks generated by the block generator. A parameter setting device sets a coding parameter to a predetermined value. A first variable-length coding device conducts variable-length coding of the pixel block selected by the block selector using the coding parameter. A code amount controller changes a value of the coding parameter so that the code amount of the pixel block selected by the block selector and coded by the first variable-length coding device is not more than a predetermined code amount, and a second variable-length coding device conducts variable-length coding of all of the pixel blocks using a coding parameter changed by the code amount controller.

Image information coding apparatus and method using code amount of a

Transfer control information for controlling a transfer amount per unit time of a transfer path is delivered from a transfer control section to an information transfer section. During encoding, the information transfer section receives image information from an external device in accordance with the transfer control information, and inputs the same to an image-information encoding/decoding section. A code-amount control section forwards code-amount control information for controlling the code amount to the image-information encoding/decoding section. The image-information encoding/decoding section encodes the image information in accordance with the code-amount control information outputted from the code-amount control section. The information transfer section transfers to an external device encoded information outputted from the image-information encoding/decoding section, while the transfer amount per unit time is being controlled by the transfer control section.

Image information encoding/decoding apparatus assuring a minimum

The present invention provides a program control system comprises plural programs each of which includes an instruction to execute a process corresponding to each of plural statuses of the system, a program memory for storing the plural programs, a program counter for outputting an address of the memory at which a part of the plural programs to be executed is stored, the address including a flag which indicates one of the plural statuses, and execution means for reading one of the programs from the program memory in accordance with the address output by the program counter and executing the read program.

Program control system

In a coding system, when any of the prediction results of pixel value prediction sections 20 and 21 matches an object pixel, a coding section 50 codes an identifier of the pixel value prediction section whose prediction result matches the object pixel. When none of the results match the object pixel, the coding section 50 codes a prediction error of a prediction error calculation section 30. A decoding system decodes code to an identifier or prediction error and outputs pixel data from the corresponding pixel value prediction section based on the identifier or takes out pixel data from a prediction error addition section 31 based on the predication error.

Image coding system and image decoding system

An image transforming section subjects image data to compression processing. A quantizing section quantizes the transformed data using a quantization width. A variable-length coding section subjects the quantized data to variable-length coding. A code-amount computing section determines a total code amount by accumulating partial code amounts. A control section performs control based on the code amount. An estimating method selecting section adaptively selects a quantization width estimating method. A coded result storage section stores data of a code amount corresponding to the quantization width. First and second quantization width estimating sections have different quantization width estimating methods.

Image coding apparatus utilizing a plurality of different

In an image forming apparatus, memory capacity necessary for temporarily retaining image data is reduced. A decoding process is carried out by diving image data for one frame into element data for each color component Y, M, C and K. The element data for each color component is stored in the temporary memory. A controller starts conveyance of recording media on the basis of estimation of the completion time of decoding processing by a decoding speed estimator, and controls the recorders for Y, M, C and K to execute the recording process of element data retained in the temporary memory. This results in an image being recorded on the recording medium for each element data retained in the temporary memory, such that the conveyance of the recording media and the supply of data to the recorders for Y, M, C and K are matched, and the data amount to be retained in the temporary memory is reduced.

An image coding apparatus wherein an image signal including a locally high signal can be coded efficiently with minimized distortion by adaptively performing quantization for each subblock. An input image signal is divided into a plurality of subband signals by a subband division section. The subband signals from the subband division section are each divided into a plurality of subblocks by a subblock division section. In a classification section, a subband signal is classified, for each of the subblocks from the subblock division section, in terms of a feature parameter of an image, for example, a dynamic range, and a class index is outputted. In a quantization section, a quantizer is changed over for each subblock in response to the class index from the classification section. Each subblock is coded with a necessary minimum number of bits. The bit number is multiplexed with a code. Accordingly, the code can be decoded by referring to the bit number.

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Kanagawa, Japan

Koh Kamizawa