Canon Kabushiki Kaisha

Hidefumi Ohsawa

Akihiro Katayama

Yasuji Hirabayashi

Tadashi Yoshida

Yasuhiko Yasuda

Hiroshi Hosokawa

Shigeo Kato

Masahiko Yoshimoto

Izuru Sunohara

Keiji Ishizuka

Akiko Fukuhara

Naoto Kawamura

Kunihiro Yamamoto

Miyuki Enokida

Akihiro Usami

Masahiro Sakamoto

Yasuyuki Shinada

Katsutoshi Ushida

Kenichi Ohta

Yuji Nishigaki

Shinichi Ishida

To increase the cache hit ratio of a requested image and shorten the user's average waiting time, images of a CD-ROM changer are cached in an intermediate HDD having a high retrieval speed, and provided to the user. When a requested image is not cached in the intermediate HDD, the free volume of the intermediate HDD is checked. If the intermediate HDD is judged not to have a free volume, images of hierarchies having large volumes are erased from ones stored the intermediate HDD in the order from lower popuralities or older access dates.

Image management apparatus and method, image management system, and storage medium

A color image processing apparatus for digitally reading a color document and effecting digital printing comprises a character region extracting device for extracting a character region of the color document; a black portion extracting device for extracting a black portion of the color document; and a single black color processing device for processing a single black color only with respect to a region which falls within the character region and the black portion in the color document, so as to allow character portions to be distinguished favorably.

Color image processing apparatus

A half-tone image is produced by scanning a plurality of input points of an original, outputting a screened image having a plurality of black and white dots and transmitting signals representing the screened image to a marking device. The size of each plurality of dots is determined from a recursive relationship between a value of a current input point, a previous output and an error representing a difference between a value of a previous input point and the previous output.

Apparatus and method for producing a half-tone image

The invention provides an information processing apparatus in which data is encoded with a desired compression ratio without producing significant degradation in the quality of the encoded data. The apparatus includes: a monitor for monitoring the amount of encoded image data which has already been generated prior to current image data to be encoded; and an encoder for encoding the current image data to be encoded selectively using either a reversible encoding algorithm or an irreversible encoding algorithm wherein the encoding algorithm is selected depending on the above-described amount of codes.

Information processing apparatus and method which selectively controls data encoding by monitoring amount of encoded data

There is provided a coding apparatus and method for hierarchically coding an image, in which a number of consecutive lines of image data representing pixels of the image are entered line by line. Reduced image data representing pixels of a reduced image based on the entered image data are formed. A determination is made in parallel with the formation of the reduced image data as to whether or not image data of an object pixel to be coded can be predicted from the reduced image data and from image data representing surrounding pixels of the entered object pixel. The entered image data are coded in accordance with the determination result.

Coding method and apparatus therefor

At the encoding side, a sum of code lengths of a block is calculated and stored in a memory for each of block lines (stripes); and at the decoding side, when decoding of one block is completed, a head address of a code in the next block is calculated utilizing a sum of an amount of codes utilized for the decoding operation and code lengths for each of the stripes. The rotation process of an image utilizing encoded data is performed in accordance with the head address. Further, at the encoding side, colors of pixels in a predetermined block is determined, and encoding operation is performed block by block for only those blocks including pixels of different colors. At the decoding side, an address of block data for sequentially constructing a rotated image is controlled to decode the pixels in the block, and finally the rotation process is performed on the pixels in the block in accordance with the color of the pixels.

Image encoding and decoding apparatus

An image processing apparatus comprising binarization means for converting a multi-level color signal into binary form, removal means for removing edge component from the multi-level color signal, based on a binary color signal from said binarization means, and encoder means for encoding the binary color signal from said binarization means and the multi-level color signal having edge component removed with said removal means.

Image processing apparatus capable of removing an edge portion from a

A color image encoding method to encode a color image signal expressed by a plural number of color component signals, wherein the plural number of color component signals of a pixel of interest are input serially, encoding conditions are serially determined in relation to each color component signal of the pixel of interest input serially, and each color component signal of the pixel of interest input serially is encoded according to the encoding conditions determined serially.

Color image encoding method

A movement vector detecting apparatus for detecting a movement vector of an object between frames which are close to each other on a block unit basis is provided. A first mode to detect the movement vector by using color components and a second mode to detect the movement vector by using a luminance component are switched in accordance with chromaticity statistics of an input block, thereby detecting the movement vector. There is also provided an encoding apparatus wherein a difference between an input signal to be encoded and a prediction value is quantized, the quantized signal is generated, the quantized differential signal is inversely quantized the sum of the inversely quantized reproduction differential signal and the prediction value is stored, the stored signal is read out on the basis of an address signal regarding the input signal, the read-out signal and the input signal are received as inputs and the prediction value is obtained, and when the prediction value is derived, an evaluation function to obtain the prediction value is determined in accordance with chromaticity statistics of the input signal.

Block matching method and apparatus which can use luminance/chrominance

An image processing apparatus having an input means which inputs coded image data for a plurality of frames, with the coded image data being coded by intraframe and interframe coding. A decoder decodes the coded image, and skips decoding of the decoded image data in units of frames when the decoding is not performed at a predetermined timing, and performs decoding of intraframe coded image data following a skipped frame.

Image processing apparatus

An encoding apparatus wherein a difference between an input signal to be encoded and a prediction value is quantized, the quantized signal is generated, the quantized differential signal is inversely quantized, the sum of the inversely quantized reproduction differential signal and the prediction value is stored, the stored signal is read out on the basis of an address signal regarding the input signal, the read-out signal and the input signal are received as inputs and the prediction value is obtained. When the prediction value is derived, an evaluation function to obtain the prediction value is determined in accordance with chromaticity statistics of the input signal.

Encoding apparatus and method for encoding a quantized difference

The invention is to exactly select an enconding method with satisfactory encoding efficiency, by comparing the final predicted code lengths for plural encoding methods, prior to the actual encoding operation. This object can be attained by an encoding device comprising generation means for generating difference data between an encoding target pixel and another pixel in each of the predetermined plural difference encoding methods, first prediction means for predicting the code length in case the difference data generated by the generation means are encoded, second prediction means for predicting the data length of additional data, other than the difference data generated by the generation means, selection means for selecting one of the difference encoding methods based on the code length predicted by the first prediction means and the data length predicted by the second prediction means, and difference encoding means for effecting difference encoding according to the result of selection by the selection means.

Selectively utilizing multiple encoding methods

When image data coded by a DCT coding method in a predetermined block size is to be decoded, an image processing apparatus extracts necessary DCT coefficients of a block on the basis of an enlargement/reduction ratio determined in advance, then decodes the extracted DCT coefficients. Thereby it is possible to produce a reduced image at high speed without using a memory of high capacity.

Image processing method and apparatus

An image processing apparatus in which a multi-level color signal is input and converted into a binary color signal. An edge component is removed from the multi-level color signal based on the binary color signal and the binary color signal and the multi-level color signal of which the edge component is removed are encoded.

Image processing apparatus and method in which multi-level color signal

An ADCT mode or a standard mode of still image encoding is employed to perform fixed length encoding. According to the present invention, an image processing apparatus includes a circuit for counting code lengths, a circuit for cutting off encoding of a block (appending an end of block (EOB) code at an earlier step). Therefore, when an average code length is longer than a predetermined value, EOB is allocated in the middle of encoding of a block. Thus, code lengths are controlled.

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Kawaguchi, Japan

Hidefumi Ohsawa