Image processing apparatus, image processing method and computer-readable medium on which image processing program is recorded
AssigneeFujitsu Limited
InventorJun Moroo
Life of this patent
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Abstract
The invention provides an image processing apparatus which can correct distortion of read image data using only the image data without using a two-dimensional sensor. The image processing apparatus includes an estimation section for estimating a displacement amount between part data which form image data based on a cross-correlation between the part data, and a correction section for correcting the image data so as to cancel a displacement in the image data based on the displacement amount estimated by the estimation section. The image processing apparatus is used to correct distortion of an image, particularly a document image, inputted from an image inputting apparatus such as, for example, a handheld image scanner.
Claims46
An image processing apparatus for performing a process for image data including a plurality of rows of line image data extending along a main scanning direction defined as a leftward and a rightward direction expediently, and arranged in a sub scanning direction defined as an upward and a downward direction expediently, comprising:
- estimation means for successively extracting line image data for one row from the image data and estimating a displacement amount in the main scanning direction between the line image data based on a cross-correlation between the extracted line image data;
- and
- correction means for correcting the image data so as to cancel a displacement in the main scanning direction in the image data based on the displacement amount in the main scanning direction estimated by said estimation means.
An image processing method for performing a process for image data which are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and a rightward direction expediently, and arranged in a sub scanning direction defined as an upward and a downward direction expediently, comprising:
- successively extracting line image data for one row from the image data and estimating a displacement amount in the main scanning direction between the line image data based on a cross-correlation between the extracted line image data;
- and
- correcting the image data so as to cancel a displacement in the main scanning direction in the image data based on the displacement amount in the main scanning direction estimated by the estimation step.
A computer-readable recording medium on which an image processing program which causes a computer to execute an image processing function for performing a process for image data including a plurality of rows of line image data extending along a main scanning direction defined as a leftward and a rightward direction expediently, and arranged in a sub scanning direction defined as an upward and a downward direction expediently, is recorded, the image processing program causing a computer to function as:
- successively extracting line image data for one row from the image data and estimating a displacement amount in the main scanning direction between the line image data based on a cross-correlation between the extracted line image data;
- and
- correcting the image data so as to cancel a displacement in the main scanning direction in the image data based on the displacement amounts in the main scanning direction estimated by said estimation means.
An image processing apparatus for performing a process for image data which are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and rightward direction expediently, and arranged in a sub scanning direction defined as an upward and downward direction expediently, comprising:
- estimation means for estimating, based on a cross-correlation between part data which form the plurality of rows of line image data, displacement amounts in the main scanning direction on the left side and the right side of the image data;
- detection means for detecting inclinations of an image on the opposite upper and lower sides of the image data based on the image data;
- and
- reconfiguration means for reconfiguring the image data based on the displacement amounts in the main scanning direction estimated by said estimation means and the inclinations detected by said detection means to cancel a distortion of the image data.
An image processing method for performing a process for image data which are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and rightward direction expediently, and arranged in a sub scanning direction defined as an upward and downward direction expediently, comprising:
- an estimation step of estimating, based on a cross-correlation between part data which form the plurality of rows of line image data, displacement amounts in the main scanning direction on the left side and the right side of the image data;
- a detection step of detecting inclinations of an image on the opposite upper and lower sides of the image data based on the image data;
- and
- a reconfiguration step of reconfiguring the image data based on the displacement amounts of the main scanning direction estimated by the estimation step and the inclinations detected by the detection step to cancel a distortion of the image data.
A computer-readable recording medium on which an image processing program which causes a computer to execute an image processing function for performing a process for image data which are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and rightward direction expediently, and arranged in a sub scanning direction defined as an upward and downward direction expediently, is recorded, the image processing program causing a computer to function as:
- estimation means for estimating displacement amounts in the main scanning direction on the left side and the right side of the image data based on a cross-correlation between part data which form a plurality of rows of line image data;
- detection means for detecting inclinations of an image on the opposite upper and lower sides of the image data based on the image data;
- and
- reconfiguration means for reconfiguring the image data based on the displacement amounts in the main scanning direction estimated by said estimation means and the inclinations detected by said detection means to cancel a distortion of the image data.
An image processing apparatus for performing a process for image data are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and rightward direction expediently, and arranged in a sub scanning direction defined as an upward and downward direction expediently, comprising:
- division means for dividing the image data into a plurality of blocks in the sub scanning direction;
- inclination estimation means for estimating inclinations of an image on the opposite upper and lower sides of each of the blocks obtained by the division by said division means;
- displacement amount estimation means for estimating displacement amounts in the main scanning direction on the left side and the right side of each of the blocks based on a cross-correlation between part data which form line image data in the block;
- and
- reconfiguration means for reconfiguring, for each of the blocks, the image data in the block based on the displacement amounts in the main scanning direction estimated by said displacement amount estimation means and the inclinations of the image on the opposite upper and lower sides of the block estimated by said inclination estimation means to cancel a distortion of the image data in the block.
An image processing method for performing a process for image data which are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and rightward direction expediently, and arranged in a sub scanning direction defined as an upward and downward direction expediently, comprising:
- a division step of dividing the image data into a plurality of blocks in the sub scanning direction;
- an inclination estimation step of estimating inclinations of an image on the opposite upper and lower sides of each of the blocks obtained by the division by said division step;
- a displacement amount estimation step of estimating displacement amounts in the main scanning direction on the left side and the right side of each of the blocks based on a cross-correlation between part data which form line image data in the blocks;
- and
- a reconfiguration step of reconfiguring, for each of the blocks, the image data in the block based on the displacement amounts in the main scanning direction estimated by the displacement amount estimation step and the inclinations on the opposite upper and lower sides of the block estimated by the inclination estimation step to cancel a distortion of the image data in the block.
A computer-readable recording medium on which an image processing program which causes a computer to execute an image processing function for performing a process for image data which are a plurality of rows of line image data extending along a main scanning direction defined as a leftward and rightward direction expediently, and arranged in a sub scanning direction defined as an upward and downward direction expediently, is recorded, the image processing program causing a computer to function as:
- division means for dividing the image data into a plurality of blocks in the sub scanning direction;
- inclination estimation means for estimating inclinations of an image on the opposite upper and lower sides of each of the blocks obtained by the division by said division means;
- displacement amount estimation means for estimating displacement amounts of the main scanning direction on the left side and the right side of the blocks based on a cross-correlation between part data which form line image data in the blocks;
- and
- reconfiguration means for reconfiguring, for each of the blocks, image data in the block based on the displacement amounts of the main scanning direction estimated by said displacement amount estimation means and the inclinations on the opposite upper and lower sides of the block estimated by said inclination estimation means to cancel a distortion of the image data in the block.
Dependencies are inferred from the claim text.