Fuji Xerox Co., Ltd.

Akihiro Andoh

Yutaka Koshi

Shunichi Kimura

Koh Kamizawa

Setsu Kunitake

Shinji Shishido

Taro Yokose

A color image of a dot-sequential system is converted into a color image of a field-sequential system and a color image can be encoded/decoded at a high speed with a high compression ratio. A pixel value of image data of a dot-sequential system is sequentially inputted to a reference area generating means, and the reference area generating means outputs target pixel data and reference area data. A same pixel value distributing and generating means generates and outputs a same pixel value distribution from the target pixel data and the reference area data. A predictive information encoding means encode data in accordance with an encoding generating table, and outputs predictive information encoded data and an encoding result signal. A dot-sequential/field-sequential image converting means converts pixel data of dot-sequential system into image data of field-sequential system when data cannot be encoded. A predictive error calculating means calculates and outputs a predictive error based on a pixel value data of field-sequential system. A predictive error encoding means encodes a predictive error, for example, in an arithmetic coding fashion.

Color image encoding apparatus and color image decoding apparatus

An image coding apparatus and method efficiently compresses a variety of images by a lossless or near-lossless coding, and an image decoding apparatus and method decodes code data encoded by the image coding apparatus and method. A windowing unit determines peripheral pixel values, which include a coding object pixel value and values of pixels located near the coding object pixel. An approximation unit uses plural approximation methods so as to output decoded pixel candidates, each of which approximates the coding object pixel value based on the values of the nearby pixels by using one of the plural approximation methods. The plural approximation methods can include an interpolation method and a quantization method. A minimum error selector calculates an error between the coding object pixel value and each of the decoded pixel candidates, and outputs a rank of the approximation method that produced the minimum error. A rank/runlength calculator counts the runlength of first ranks and outputs a coding symbol. The coding symbol can be the rank or the runlength. An encoder encodes the coding symbol so as to output code data.

Image coding apparatus and method, and image decoding apparatus and method

The present invention has an object to determine whether image data is generated by data processing such as PDL, or optically captured scan-in image, for each area. To achieve the object, a determining table is provided for distribution patterns of pixels having substantially the same pixel value for image data area composed of plural pixels. Then a reference area designating unit designates a reference area by selecting from input image data the pixel of interest having a pixel value and the reference pixels surrounding thereof. A same pixel value distribution generating unit compares the pixel value of the pixel of interest with the pixel values of the reference pixels in the reference area to generate a distribution pattern of the pixel having substantially the same pixel value. Next, a determining unit compares the generated distribution pattern with the distribution patterns held in the determining table to determine the reference area to be the image data generated by data processing.

Image processing apparatus

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

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

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 auxiliary storage controlling device is able to assure the data transferring rate even when an irregular occurs. The controlling device comprises a plurality of auxiliary storage units each of which stores the same data, a readout system for reading out said data from said plurality of auxiliary storage units simultaneously in response to a readout command, a detecting system for detecting an auxiliary storage unit in which the reading out of said data is finished at the earliest, a selecting system for selecting said data which is read from said detected auxiliary storage unit, an irregular detecting system for detecting an irregular auxiliary storage unit which is still working, and a readout prohibiting system for prohibiting a consecutive readout command against said irregular auxiliary storage unit. Additional features to assure the data transferring rate are also disclosed.

Growing community of inventors

Nakai-machi, Japan

Akihiro Andoh