Image reading apparatus and image reading method
AssigneeCanon Kabushiki Kaisha
InventorSatoshi Tada
Life of this patent
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Abstract
An image reading apparatus has an image sensor in which a plurality of sensor arrays for reading a document image are connected into a line, and parallel-output image data. In the image reading apparatus, of image data output from each sensor array, image data of a pixel at one end and image data of the remaining pixels are compressed by different compression methods. The compressed data of one line are decompressed by a set method at the timing when the number of pixels reaches a preset number of pixels.
Claims7
An image reading apparatus having an image sensor in which a plurality of sensors for reading a document image are arranged into a line, the apparatus comprising:
- a compression unit configured to compress image data of a pixel at one end read by each sensor in the image sensor by a first compression process and to compress image data of remaining pixels in the each sensor in the image sensor by a second compression process different from the first compression process;
- a storage unit configured to store the image data compressed by said compression unit;
- a decompression unit configured to decompress the image data output from said storage unit;
- and
- a counting unit configured to count the number of pixels input to said decompression unit;
- wherein when the number of pixels counted by said counting unit matches a predetermined number, said decompression unit changes a decompression process for the image data stored by said storage unit between a first decompression process for the image data compressed by the first compression process and a second decompression process for the image data compressed by the second compression process.
An image reading method for an image reading apparatus having an image sensor in which a plurality of sensors for reading a document image are arranged into a line, the method comprising:
- compressing image data of a pixel at one end read by each sensor in the image sensor by a first compression process and compressing image data of remaining pixels in the each sensor in the image sensor by a second compression process different from the first compression process;
- storing the image data compressed in the compressing in a storage unit;
- decompressing the image data output from the storage unit in accordance with a first decompression process for the image data compressed by the first compression process and a second decompression process for the image data compressed by the second compression process;
- counting the number of pixels output from the storage unit;
- and
- changing, when the counted number of pixels matches a predetermined number, a decompression process for the image data stored in the storage unit between the first decompression process and the second decompression process.
Dependencies are inferred from the claim text.