Image data processing apparatus having line memory
First Claim
1. An image data processing apparatus, to which data, representative of pixels on each of a plurality of scanning lines, are sequentially supplied, said apparatus performing processing with data corresponding to N lines including supplied data corresponding to a present line to which pixels represented by the supplied data belong and data corresponding to (N-1) other lines scanned just ahead of the present line, said apparatus comprising:
- storing means, having a data capacity corresponding to (N-1) lines, for storing data representative of pixels belonging to the (N-1) lines scanned just ahead of the present line;
means for sequentially reading out from the storing means, data representative of pixels belonging to the (N-1) lines scanned just ahead of the present line to provide read data, the reading means reading out data representative of a pixel belonging to the line scanned (N-1) lines ahead of the present line in parallel with data representative of pixels belonging to other lines scanned ahead of the present line;
processing means, to which the read data representative of the pixels belonging to the (N-1) lines and the data representative of the pixels belonging to the present line are applied, for performing predetermined processing; and
means for writing the supplied data representative of the pixels belonging to the present line to storage locations from which data representative of pixels belonging to a line scanned (N-1) lines ahead of the present line have been read out from said storing means before the reading out means reads out, from the storing means, all data representative of pixels belonging to the line scanned (N-1) lines ahead of the present line.
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Accused Products
Abstract
An image data processing apparatus for performing processing using data corresponding to a plurality of lines which correspond to a plurality of scanning lines at the time of reading an image. For example, when processing is performed using data corresponding to three lines, that is, the present line, a line one ahead of the present line and a line two lines ahead of the present line, a line memory having a capacity of two lines is used. When the data corresponding to the line two lines ahead of the present line are read out from the memory, the data corresponding to the present line are written to storage locations from which the data have been read out. Consequently, it is possible to perform processing using data corresponding to three lines using a line memory having a capacity for two lines.
15 Citations
16 Claims
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1. An image data processing apparatus, to which data, representative of pixels on each of a plurality of scanning lines, are sequentially supplied, said apparatus performing processing with data corresponding to N lines including supplied data corresponding to a present line to which pixels represented by the supplied data belong and data corresponding to (N-1) other lines scanned just ahead of the present line, said apparatus comprising:
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storing means, having a data capacity corresponding to (N-1) lines, for storing data representative of pixels belonging to the (N-1) lines scanned just ahead of the present line; means for sequentially reading out from the storing means, data representative of pixels belonging to the (N-1) lines scanned just ahead of the present line to provide read data, the reading means reading out data representative of a pixel belonging to the line scanned (N-1) lines ahead of the present line in parallel with data representative of pixels belonging to other lines scanned ahead of the present line; processing means, to which the read data representative of the pixels belonging to the (N-1) lines and the data representative of the pixels belonging to the present line are applied, for performing predetermined processing; and means for writing the supplied data representative of the pixels belonging to the present line to storage locations from which data representative of pixels belonging to a line scanned (N-1) lines ahead of the present line have been read out from said storing means before the reading out means reads out, from the storing means, all data representative of pixels belonging to the line scanned (N-1) lines ahead of the present line.
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2. An image data processing apparatus to which data pixels on each of a plurality of scanning lines, are sequentially supplied, said apparatus performing predetermined processing with data corresponding to three lines and representative of nine pixels that constitute a 3×
- 3 pixel matrix, the three line corresponding data including data corresponding to a present line to which pixels represented by the supplied data belong, data corresponding to a line scanned one line ahead of the present line, and data corresponding to a line scanned two lines ahead of the present line, said 3×
3 pixel matrix being centered with respect to a target pixel belonging to said line scanned one line ahead of the present line, said apparatus comprising;storing means, having a data capacity corresponding to two lines, for storing data representative of pixels corresponding to the line scanned one line ahead of the present line and the line scanned two lines ahead of the present line; reading means for sequentially reading out, from the storing means, data representative of pixels belonging to the lines scanned one line and two lines ahead of the present line to provide read data, the reading out means reading out data representative of a pixel belonging to the line scanned one line ahead of the present line in parallel with data representative of a pixel belonging to the line scanned two lines ahead of the present line; processing means, to which said read data representative of the pixels belonging to the lines scanned one line and two lines ahead of the present line and the data representative of the pixels belonging to the present line are applied, for subjecting data representative of the target pixel to the predetermined processing based upon predetermined data from among the data representative of the nine pixels constituting said 3×
3 pixel matrix; andwriting means for writing the supplied data representative of the pixels belonging to the present line to storage locations from which data representative of the pixels belonging to the line scanned two lines ahead of the present line have been read out from said storing means before the reading means reads out, from the storing means, all data representative of pixels belonging to the line scanned two lines ahead of the present line. - View Dependent Claims (3, 4, 5, 6, 7, 8)
- 3 pixel matrix, the three line corresponding data including data corresponding to a present line to which pixels represented by the supplied data belong, data corresponding to a line scanned one line ahead of the present line, and data corresponding to a line scanned two lines ahead of the present line, said 3×
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9. A method for binary-coding multivalued density data representative of each of plural pixels constituting an image wherein each pixel on each of a plurality of scanning lines is sequentially processed as a target pixel, said method comprising the steps of:
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obtaining first accumulated error data by accumulating data representative of binary coded-errors associated with pixels that have predetermined positional relationships with respect to a target pixel and that are scanned ahead of said target pixel on a present line to which said target pixel also belongs; reading out, from a storing means, second accumulated error data previously stored in said storing means as a result of binary-coding of density data associated with a pixel on a line scanned ahead of said present line, said second accumulated error data being representative of accumulated binary-coded errors associated with pixels that have predetermined positional relationships with said target pixel and that are on said line ahead of said present line; accumulating said first accumulated error data, said second accumulated error data, and density data associated with said target pixel to obtain binary-coding judgement value data; binary-coding said density data associated with said target pixel by comparing said binary-coding judgement value data with a predetermined binary-coding threshold value and binary-coding said binary-coding judgement value data into a first value data if said binary-coding judgment value data are not less than said predetermined binary-coding threshold value, and into second value data if said binary-coding judgement value data are less than said predetermined binary-coding threshold value; calculating binary-coded error data of said target pixel as a difference between said binary-coding judgement value data and a value corresponding to said first value data if said binary-coding judgement value data have been binary-coded into said first value data, and as a difference between said binary-coding judgement value data and a value corresponding to said second value data if said binary-coding judgement value data have been binary-coded into said second value data; obtaining third accumulated error data by accumulating said binary coded-error data of said target pixel and said data representative of binary coded-errors of said pixels scanned ahead of said target pixel on said present line, said third accumulated error data being applicable as a second accumulated error, associated with a pixel that is on a line scanned after said present line and that has a predetermined positional relationship with said target pixel, when density data associated with said pixel on said line scanned after said present line are binary-coded; and storing said third accumulated error data in said storing means. - View Dependent Claims (10, 11, 12)
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13. An apparatus for binary-coding multivalued density data representative of each of plural pixels constituting an image wherein each pixel on each of a plurality of scanning lines is sequentially processed as a target pixel, said apparatus comprising:
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storing means; means for obtaining first accumulated error data by accumulating data representative of binary coded-errors associated with pixels that have predetermined positional relationships with respect to a target pixel and that are scanned ahead of said target pixel on a present line to which said target pixel also belongs; means for reading out, from said storing means, second accumulated error data previously stored in said storing means as a result of binary-coding of density data associated with a pixel on a line scanned ahead of said present line, the second accumulated error data being representative of accumulated binary-coded errors associated with pixels that have predetermined positional relationships with said target pixel and that are on said line ahead of said present line; means for accumulating first accumulated error data from said first accumulated error data obtaining means, second accumulated error data from said reading out means, and density data associated with said target pixel to obtain binary-coding judgement value data; means for binary-coding density data associated with said target pixel by comparing binary-coding judgement value data from said first accumulated error data accumulating means with a predetermined binary-coding threshold value and binary-coding such binary-coding judgment value data into first value data if such binary-coding judgment value data are not less than said predetermined binary-coding threshold value and into second value data if such binary-coding judgment value data are less than said predetermined binary-coding threshold value; means for calculating binary-coded error data of said target pixel as a difference between binary-coding judgement value data from said first accumulated error data accumulating means and a value corresponding to said first value data if such binary-coding judgement value data have been binary-coded into said first value data, and as a difference between such binary-coding judgement value data and a value corresponding to said second value data if such binary-coding judgement value data have been binary-coded into said second value data; means for obtaining third accumulated error data by accumulating binary coded-error data of said target pixel from said calculating means and data representative of binary coded-errors of said pixels scanned ahead of said target pixel on said present line, said third accumulated error data being applicable as a second accumulated error, associated with a pixel that is on a line scanned after said present line and that has a predetermined positional relationship with said target pixel, when density data associated with said pixel on said line scanned after said present line are binary-coded; and means for storing third accumulated error data from said third accumulated error data obtaining means in said storing means. - View Dependent Claims (14, 15, 16)
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Specification