Patents by Inventor Hidefumi Ohsawa

Hidefumi Ohsawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6509900
    Abstract: 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.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: January 21, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Yasuhiko Yasuda
  • Patent number: 6415052
    Abstract: 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.
    Type: Grant
    Filed: February 24, 1995
    Date of Patent: July 2, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Ohsawa
  • Publication number: 20010019631
    Abstract: This invention provides an image processing apparatus and method characterized by inputting successive image data, detecting a change in the image data, generating initial contour information for extracting an object present in the image data in accordance with the detection result, and extracting object image data corresponding to the object on the basis of the generated initial contour information.
    Type: Application
    Filed: December 29, 2000
    Publication date: September 6, 2001
    Inventors: Hidefumi Ohsawa, Osamu Itokawa
  • Patent number: 6285464
    Abstract: 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.
    Type: Grant
    Filed: October 8, 1992
    Date of Patent: September 4, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiro Katayama, Hidefumi Ohsawa, Akiko Fukuhara
  • Patent number: 6266449
    Abstract: 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.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: July 24, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Ohsawa
  • Patent number: 6026197
    Abstract: 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.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: February 15, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Keiji Ishizuka
  • Patent number: 5991450
    Abstract: 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.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: November 23, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Yasuji Hirabayashi, Katsutoshi Ushida
  • Patent number: 5917956
    Abstract: 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.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: June 29, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Yasuji Hirabayashi, Tadashi Yoshida
  • Patent number: 5903366
    Abstract: 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.
    Type: Grant
    Filed: October 15, 1993
    Date of Patent: May 11, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuji Hirabayashi, Hidefumi Ohsawa, Tadashi Yoshida
  • Patent number: 5900910
    Abstract: 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.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: May 4, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuji Hirabayashi, Tadashi Yoshida, Hidefumi Ohsawa
  • Patent number: 5898461
    Abstract: 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.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: April 27, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Kunihiro Yamamoto
  • Patent number: 5892546
    Abstract: 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.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 6, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuji Hirabayashi, Tadashi Yoshida, Hidefumi Ohsawa
  • Patent number: 5883976
    Abstract: 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.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: March 16, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Ohsawa
  • Patent number: 5875039
    Abstract: 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.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: February 23, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Yasuji Hirabayashi
  • Patent number: 5844718
    Abstract: 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.
    Type: Grant
    Filed: August 4, 1994
    Date of Patent: December 1, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidefumi Ohsawa, Yasuji Hirabayashi, Tadashi Yoshida
  • Patent number: 5840741
    Abstract: 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido?1, 2-a!pyrimidin-4-one represented by the following formula; ##STR1## and the physiologically-acceptable salts thereof showed to have excellent inhibitory effect on the proliferation of vascular smooth muscle cells and are effective to prevent the occurrence of restenosis after the operation of PTCA, and hence the compounds can be useful for the therapeutic and preventive treatment for arteriosclerosis and other diseases whereto the proliferation of vascular smooth muscle cells is directly concerned.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: November 24, 1998
    Assignee: Tokyo Tanabe Company Limited
    Inventors: Hisao Tomioka, Hidefumi Ohsawa, Masao Moroi, Toshio Kawashima
  • Patent number: 5825934
    Abstract: 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.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: October 20, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Ohsawa
  • Patent number: 5818537
    Abstract: Image processing method and apparatus for converting between data encoded in different formats includes structure and steps for converting motion image data into first digital coded motion image data having a first encoding format and capable of being transmitted to a medium. The first digital coded motion image data is then converted into second digital coded motion image data without decoding entirely the first digital coded motion image data. The second digital coded motion image data has a second encoding format different from the first encoding format. Preferably, the second digital coded motion image data has a digital data amount which is less than that of the first digital coded motion image data.
    Type: Grant
    Filed: December 2, 1996
    Date of Patent: October 6, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Miyuki Enokida, Hidefumi Ohsawa
  • Patent number: 5790195
    Abstract: The invention provides an image processing apparatus comprising: an activity detecting unit for detecting an activity of input image data, a processing unit for space filter processing the input image data by controlling filter coefficients in accordance with the activity detected by the activity detecting unit, and an encoding unit for encoding the input image data processed by the processing unit. An image processing apparatus comprising, an activity detecting unit for detecting an activity of input image data, and a quantizing unit for quantizing the input image data by controlling a quantization step in accordance with the activity detected by the activity detecting unit is also provided.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: August 4, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Ohsawa
  • Patent number: 5732153
    Abstract: 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.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: March 24, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Ohsawa