Canon Kabushiki Kaisha

Yasuhiko Yasuda

Shigeo Kato

Akihiro Katayama

Hidefumi Ohsawa

Hirokazu Uchio

Hidefumi Osawa

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

This invention relates to an image processing apparatus having a function of encoding or decoding image data and discloses a technique for extracting an image feature, especially a thin image portion of a specific color of an image, and for encoding the thin image portion with high efficiency to minimize degradation of image quality by selecting an appropriate encoding method.

Color image encoding method and apparatus

There is provided an image encoding method in a facsimile apparatus or an image filing apparatus as an image communication apparatus. In this method, a color image signal which is expressed by a plurality of color component signals to be encoded is input, the input color image signal is converted into a bit stream signal, and the bit stream signal is encoded by prediction encoding. A parameter for the prediction encoding is changed in accordance with the color image signal to be encoded. The encoding operation is executed adaptively to the color image signal to be encoded. By virtue of bit stream converting the binary color signal, efficient encoding using the color correlation can be executed and an increase in data amount is prevented. By encoding the bit stream signal using a dynamic arithmetic code, a binary color image can be efficiently encoded.

Image encoding method

Apparatus and method for decoding differently encoded multi-level and

Method and apparatus for efficiently encoding image data of a color facsimile or the like are provided. A specific color judgment unit discriminates a specific color portion such as white or blank portion of the image data inputted from an image input unit. An orthogonal transforming process is not executed to the blank block, thereby raising an encoding efficiency. A discrimination signal is subjected to a dynamic arithmetical encoding, thereby producing code data.

Image processing apparatus for advantageously encoding blocks of data

The invention relates to an image processing apparatus having the function to encode or decode image data and discloses a technique in which an optimum encoding method is selected in accordance with the characteristics of an image and a high efficient encoding with little deterioration in image is executed.

Method and apparatus for encoding or decoding an image in accordance

Method and apparatus for encoding and decoding color images

In an image encoding method in which a pixel of interest is predicted with reference to a plurality of pixels near the pixel of interest to be encoded, and encoding is performed on the basis of coincidence/noncoincidence between the predicted pixel and the pixel of interest, a parameter for predicting a pixel is changed on the basis of a rate of coincidence/noncoincidence of the predicted pixel and the pixel of interest.

There is provided an image encoding method in a facsimile apparatus or an image filing apparatus as an image communication apparatus. In this method, a color image signal which is expressed by a plurality of color component signals to be encoded is input, the input color image signal is converted into a bit stream signal, and the bit stream signal is encoded by the prediction encoding. A parameter for the prediction encoding is changed in accordance with the color image signal to be encoded. The encoding operation is executed adaptively to the color image signal to be encoded. By bit stream converting the binary color signal, the efficient encoding using the color correlation can be executed and an increase in data amount is prevented. By encoding the bit stream signal by using a dynamic arithmetic code, a binary color image can be efficiently encoded.

Image encoding method and apparatus providing variable length bit stream

An image encoding apparatus includes a smoothing circuit for smoothing a binary image to be encoded, a binary-encoding circuit for binary-encoding the image smoothed by the smoothing circuit, a sampling circuit for sub-sampling the image binary-encoded by the binary-encoding circuit, and an encoding circuit for encoding the binary image sub-sampled by the sampling circuit. A degree of smoothness of an image by the smoothing circuit and a threshold value for a binary-encoding operation of the binary-encoding circuit can be varied.

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Musashino, Japan

Yasuhiko Yasuda