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US5499111A
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Image signal processing apparatus
Assignee: Panasonic System Solutions Japan Co Ltd
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Filing: 1992-08-04
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Granted: 1996-03-12
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Expires: 2012-08-04
Abstract
Abstract A correcting device corrects a multi-level image signal of a pixel of interest in accordance with corrective data. A binarizing device binarizes an output signal of the correcting device. A logic device receives an output signal of the binarizing device. A feedback device feeds an output signal of the logic device, which corresponds to at least two feedback pixels immediately preceding the pixel of interest in a scanning direction, back to an input side of the logic device. A calculating device derives a difference between an output signal of the logic device and the output signal of the correcting device, and generates the corrective data on the basis of the derived difference. An output signal of the logic device is a pseudo halftone image signal. The logic device operates as follows. A black-level signal is outputted as a signal of the pixel of interest when the output signal of the logic device which corresponds to the feedback pixel closest to the pixel of interest is black and the output signal of the logic device which corresponds to the other feedback pixel is white. A signal equal to the output signal of the binarizing device is outputted as a signal of the pixel of interest in other cases. A white-level signal is outputted as a signal of the pixel of interest when the output signal of the logic device which corresponds to the feedback pixel closest to the pixel of interest is white and the output signal of the logic device which corresponds to the other feedback pixel is black. A signal equal to the output signal of the binarizing device is outputted as a signal of the pixel of interest in other cases.
Inventors
- 👤 Shinichi Sato
- 👤 Kazuto Kobayashi
- 👤 Takenobu Ikeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:51
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4051; H04N1/4052; H04N1/4053
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
296 words
An image signal processing apparatus comprising: correcting means for correcting a multi-level image signal of a pixel of interest in accordance with corrective data; binarizing means for binarizing an output signal of the correcting means; logic means receiving an output signal of the binarizing means; feedback means for feeding an output signal of the logic means, which corresponds to at least two feedback pixels immediately preceding the pixel of interest in a scanning direction, back to an input side of the logic means; calculating means for derived a difference between an output signal of the logic means and the output signal of the correcting means, and generating the corrective data on the basis of the derive difference; and output means for outputting an output signal of the logic means as a pseudo halftone image signal; wherein the logic means comprises: means for outputting a black-level signal as a signal of the pixel of interest when the output signal of the logic means which corresponds to the feedback pixel closest to the pixel of interest is black and the output signal of the logic means which corresponds to the other feedback pixel is white, for outputting a signal equal to the output signal of the binarizing means as a signal of the pixel of interest in other cases; and means for outputting a white-level signal as a signal of the pixel of interest when the output signal of the logic means which corresponds to the feedback pixel closest to the pixel of interest is white and the output signal of the logic means which corresponds to the other feedback pixel is black, and for outputting a signal equal to the output signal of the binarizing means as a signal of the pixel of interest in other cases.
Claim 2
Dependent Claim
296 words
An image signal processing apparatus comprising: correcting means for correcting a multi-level image signal of a pixel of interest in accordance with corrective data; binarizing means for binarizing an output signal of the correcting means; logic means receiving an output signal of the binarizing means; feedback means for feeding an output signal of the logic means, which corresponds to at least two feedback pixels immediately preceding the pixel of interest in a scanning direction, back to an input side of the logic means; calculating means for derived a difference between an output signal of the logic means and the output signal of the correcting means, and generating the corrective data on the basis of the derive difference; and output means for outputting an output signal of the logic means as a pseudo halftone image signal; wherein the logic means comprises: means for outputting a black-level signal as a signal of the pixel of interest when the output signal of the logic means which corresponds to the feedback pixel closest to the pixel of interest is black and the output signal of the logic means which corresponds to the other feedback pixel is white, for outputting a signal equal to the output signal of the binarizing means as a signal of the pixel of interest in other cases; and means for outputting a white-level signal as a signal of the pixel of interest when the output signal of the logic means which corresponds to the feedback pixel closest to the pixel of interest is white and the output signal of the logic means which corresponds to the other feedback pixel is black, and for outputting a signal equal to the output signal of the binarizing means as a signal of the pixel of interest in other cases.
Claim 3
Dependent Claim
110 words
An image signal processing apparatus comprising: binarizing means for binarizing a multi-level input pixel signal; converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest, into one of a signal of at least two successive black dots and a signal of at least two successive white dots; calculating means for deriving a difference between an output signal of the converting means and the input pixel signal, and for generating corrective data on the basis of the derived difference; and correcting means for correcting the input pixel signal, which corresponds to pixels near a pixel of interest, in accordance with the corrective data.
Claim 4
Dependent Claim
110 words
An image signal processing apparatus comprising: binarizing means for binarizing a multi-level input pixel signal; converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest, into one of a signal of at least two successive black dots and a signal of at least two successive white dots; calculating means for deriving a difference between an output signal of the converting means and the input pixel signal, and for generating corrective data on the basis of the derived difference; and correcting means for correcting the input pixel signal, which corresponds to pixels near a pixel of interest, in accordance with the corrective data.
Claim 5
Dependent Claim
95 words
In an image signal processing apparatus outputting a plurality of black and white dots to represent a multi-level input pixel signal, the improvement comprising: binarizing means for binarizing the multi-level input pixel signal; and converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest, into one of a signal of at least two successive black dots and a signal of at least two successive white dots in a main scanning direction in accordance with states of pixels preceding the pixel of interest by two pixels or more.
Claim 6
Dependent Claim
95 words
In an image signal processing apparatus outputting a plurality of black and white dots to represent a multi-level input pixel signal, the improvement comprising: binarizing means for binarizing the multi-level input pixel signal; and converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest, into one of a signal of at least two successive black dots and a signal of at least two successive white dots in a main scanning direction in accordance with states of pixels preceding the pixel of interest by two pixels or more.
Claim 7
Dependent Claim
95 words
In an image signal processing apparatus outputting a plurality of black and white dots to represent a multi-level input pixel signal, the improvement comprising: binarizing means of binarizing the multi-level input pixel signal; and converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest, into one of a signal of at least two successive black dots and a signal of at least two successive white dots in a sub scanning direction by referring to states of pixels preceding the pixel of interest by two pixels or more.
Claim 8
Dependent Claim
95 words
In an image signal processing apparatus outputting a plurality of black and white dots to represent a multi-level input pixel signal, the improvement comprising: binarizing means of binarizing the multi-level input pixel signal; and converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest, into one of a signal of at least two successive black dots and a signal of at least two successive white dots in a sub scanning direction by referring to states of pixels preceding the pixel of interest by two pixels or more.
Claim 9
Dependent Claim
102 words
In an image signal processing apparatus outputting a plurality of black and white dots to represent a multi-level input pixel signal, the improvement comprising: binarizing means of binarizing the multi-level input pixel signal; and converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest into one of a signal of at lest two successive black dots and a signal of at least two successive white dots in one of a main scanning direction and a sub scanning direction by referring to states of pixels preceding the pixel of interest by two pixels or more.
Claim 10
Dependent Claim
102 words
In an image signal processing apparatus outputting a plurality of black and white dots to represent a multi-level input pixel signal, the improvement comprising: binarizing means of binarizing the multi-level input pixel signal; and converting means for converting an output signal of the binarizing means, which corresponds to a pixel of interest into one of a signal of at lest two successive black dots and a signal of at least two successive white dots in one of a main scanning direction and a sub scanning direction by referring to states of pixels preceding the pixel of interest by two pixels or more.
Claim 11
Dependent Claim
134 words
An image signal processing apparatus comprising: correcting means for correcting a multi-level input pixel signal in accordance with corrective data; binarizing means for binarizing an output signal of the correcting means into a corresponding binary pixel signal; reducing means for thinning out pixels in the binary pixel signal and thereby reducing the binary pixel signal; and calculating means for deriving a difference between the binary pixel signal and the output signal of the correcting means, and for generating the corrective data on the basis of the derived difference; wherein the calculating means comprises means for excluding the pixels, which are thinned out by the reducing means, from generating the corrective data to enable the correcting by the correcting means to be done only on pixels which are not thinned out by the reducing means.
Claim 12
Dependent Claim
134 words
An image signal processing apparatus comprising: correcting means for correcting a multi-level input pixel signal in accordance with corrective data; binarizing means for binarizing an output signal of the correcting means into a corresponding binary pixel signal; reducing means for thinning out pixels in the binary pixel signal and thereby reducing the binary pixel signal; and calculating means for deriving a difference between the binary pixel signal and the output signal of the correcting means, and for generating the corrective data on the basis of the derived difference; wherein the calculating means comprises means for excluding the pixels, which are thinned out by the reducing means, from generating the corrective data to enable the correcting by the correcting means to be done only on pixels which are not thinned out by the reducing means.
Claim 13
Dependent Claim
163 words
An image signal processing apparatus comprising: correcting means for correcting a multi-level input pixel signal in accordance with corrective data; binarizing means for binarizing an output signal of the correcting means into a corresponding binary pixel signal; reducing means for thinning out pixels in the binary pixel signal and thereby reducing the binary pixel signal; and calculating means for deriving a difference between the binary pixel signal and the output signal of the correcting means to generate error data; processing means for multiplying the error data of pixels near a pixel of interest by predetermined weight coefficients to generate weighted error data respectively, and for generating the corrective data on the basis of the weighted error data; wherein the processing means comprises means for excluding the pixels, which are thinned out by the reducing means, from generating the corrective data to enable the correcting by the correcting means to be done only on pixels which are not thinned out by the reducing means.
Claim 14
Dependent Claim
163 words
An image signal processing apparatus comprising: correcting means for correcting a multi-level input pixel signal in accordance with corrective data; binarizing means for binarizing an output signal of the correcting means into a corresponding binary pixel signal; reducing means for thinning out pixels in the binary pixel signal and thereby reducing the binary pixel signal; and calculating means for deriving a difference between the binary pixel signal and the output signal of the correcting means to generate error data; processing means for multiplying the error data of pixels near a pixel of interest by predetermined weight coefficients to generate weighted error data respectively, and for generating the corrective data on the basis of the weighted error data; wherein the processing means comprises means for excluding the pixels, which are thinned out by the reducing means, from generating the corrective data to enable the correcting by the correcting means to be done only on pixels which are not thinned out by the reducing means.
Claim 15
Dependent Claim
209 words
An image signal processing apparatus comprising: correcting means for correcting input image data in accordance with first corrective data; binarizing means for binarizing an output signal of the correcting means; subtracting means for calculating a difference between an output signal of the binarizing means and the output signal of the corrective means; memory means for memorizing binary values of already-processed pixels, which are represented by the output signal of the binarizing means, near a currently-processed pixel; first corrective-quantity determining means for determining second corrective data on the basis of the binary values of the already-processed pixels which are memorized by the memory means, the second corrective data depending on a difference between a theoretical dot size and an actual dot size in a recording system; second corrective-quantity determining means for adding an output signal of the first corrective-quantity determining means and an output signal of the subtracting means to generate the first corrective data; receiving means for receiving a signal representing whether or not the input image signal is effective; and feeding means for feeding an output signal of the second corrective-quantity determining means to the correcting means as the first corrective data when the signal received by the receiving means represents that the input image signal is effective.
Claim 16
Dependent Claim
209 words
An image signal processing apparatus comprising: correcting means for correcting input image data in accordance with first corrective data; binarizing means for binarizing an output signal of the correcting means; subtracting means for calculating a difference between an output signal of the binarizing means and the output signal of the corrective means; memory means for memorizing binary values of already-processed pixels, which are represented by the output signal of the binarizing means, near a currently-processed pixel; first corrective-quantity determining means for determining second corrective data on the basis of the binary values of the already-processed pixels which are memorized by the memory means, the second corrective data depending on a difference between a theoretical dot size and an actual dot size in a recording system; second corrective-quantity determining means for adding an output signal of the first corrective-quantity determining means and an output signal of the subtracting means to generate the first corrective data; receiving means for receiving a signal representing whether or not the input image signal is effective; and feeding means for feeding an output signal of the second corrective-quantity determining means to the correcting means as the first corrective data when the signal received by the receiving means represents that the input image signal is effective.
Claim 17
Dependent Claim
25 words
The image signal processing apparatus of claim 8, further comprising means for outputting data of zero to the correcting means as the first corrective data.
Claim 18
Dependent Claim
17 words
The image signal processing apparatus of claim 8, further comprising means for changing the second corrective data.
Claim 19
Dependent Claim
138 words
The image signal processing apparatus of claim 8, wherein the second corrective-quantity determining means comprises means for storing data of two sets of coefficients, means for generating a signal of a random number, means for selecting one of the two coefficient sets in accordance with the random number signal, and means for generating the first corrective data on the basis of the selected coefficient set, and wherein the random number signal generating means comprises first sub random number signal generators, a second sub random number signal generator different from the first sub random number signal generators, and means for selecting one of output signals of the first sub random number signal generator in response to an output signal of the second sub random number signal generator, and for outputting the selected output signal as the random number signal.
Claim 20
Dependent Claim
34 words
The image signal processing apparatus of claim 11, further comprising means for synchronizing an operation clock signal of the first sub random number signal generators with a clock signal of the input image signal.
Claim 21
Dependent Claim
36 words
The image signal processing apparatus of claim 11, further comprising means for synchronizing an operation clock signal of the second sub random number signal generator with a main scanning line component of the input image signal.
Claim 22
Dependent Claim
127 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by first predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; correcting means for calculating and processing the filter correction value; binarizing means for binarizing an output signal of the correcting means; a subtraction circuit for calculating a subtraction value between an output signal of the binarizing means and the output signal of the correcting means; and correction value calculating means for multiplying subtraction values of pixels adjoining a pixel to be binarized which are already outputted from the subtraction circuit by second predetermined coefficients, and for outputting resultants to the correcting means.
Claim 23
Dependent Claim
127 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by first predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; correcting means for calculating and processing the filter correction value; binarizing means for binarizing an output signal of the correcting means; a subtraction circuit for calculating a subtraction value between an output signal of the binarizing means and the output signal of the correcting means; and correction value calculating means for multiplying subtraction values of pixels adjoining a pixel to be binarized which are already outputted from the subtraction circuit by second predetermined coefficients, and for outputting resultants to the correcting means.
Claim 24
Dependent Claim
35 words
The image signal processing apparatus of claim 14, wherein the first coefficients have values which are different between positions vertically and horizontally adjoining the pixel of interest and positions obliquely adjoining the pixel of interest.
Claim 25
Dependent Claim
70 words
The image signal processing apparatus of claim 14, wherein the first coefficients have values of 1/8 as coefficients of positions vertically and horizontally adjoining the pixel of interest, and the first coefficients have negative values as coefficients of positions obliquely adjoining the pixel of interest, and wherein a sum of the first coefficient of the pixel of interest and the first coefficients of the adjoining pixels is equal to 1.
Claim 26
Dependent Claim
44 words
The image signal processing apparatus of claim 14, wherein a sum of the first coefficients is equal to 1 in a position of the pixel of interest, positions vertically and horizontally adjoining the pixel of interest, and positions obliquely adjoining the pixel of interest.
Claim 27
Dependent Claim
19 words
The image signal processing apparatus of claim 14, wherein a sum of the second coefficients is equal to 1.
Claim 28
Dependent Claim
30 words
The image signal processing apparatus of claim 14, wherein the binarizing means comprises a binarizing comparator for comparing input data and a predetermined threshold value to calculate a binary level.
Claim 29
Dependent Claim
35 words
The image signal processing apparatus of claim 14, wherein the binarizing means comprises a binarizing decoder for calculating a binary level from a sign bit and higher bits of data outputted from the correcting means.
Claim 30
Dependent Claim
91 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; and a binarizing comparator for comparing a dither pattern outputted from the dither pattern generating circuit and the filter correction value to determine a binary level of the pixel of interest.
Claim 31
Dependent Claim
91 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; and a binarizing comparator for comparing a dither pattern outputted from the dither pattern generating circuit and the filter correction value to determine a binary level of the pixel of interest.
Claim 32
Dependent Claim
90 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; an adder for adding a dither pattern outputted from the dither pattern generating circuit and the filter correction value; and binarizing means for binarizing an output signal of the adder.
Claim 33
Dependent Claim
90 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; an adder for adding a dither pattern outputted from the dither pattern generating circuit and the filter correction value; and binarizing means for binarizing an output signal of the adder.
Claim 34
Dependent Claim
109 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; an adder for adding a dither pattern outputted from the dither pattern generating circuit and the filter correction value being an output signal of the edge emphasizing filter; and means for outputting information of whether a carry bit of the adder is present or absent as a binary value.
Claim 35
Dependent Claim
109 words
An image signal processing apparatus comprising: an edge emphasizing filter for multiplying a pixel of interest and pixels adjoining the pixel of interest of an input multi-level image signal by predetermined coefficients, and for calculating a filter correction value equal to a sum thereof; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; an adder for adding a dither pattern outputted from the dither pattern generating circuit and the filter correction value being an output signal of the edge emphasizing filter; and means for outputting information of whether a carry bit of the adder is present or absent as a binary value.
Claim 36
Dependent Claim
209 words
An image signal processing apparatus comprising: an edge emphasizing filter including means for inputting a positive value "A" and a negative value "-B" as filter coefficients to emphasize edges in an image, means for using the input value "A" as filter coefficients of pixels adjoining a pixel of interest in main and sub scanning directions, means for using the input value "-B" as filter coefficients of pixels adjoining the pixel of interest in inclined directions, means for using a value "1+4B-4A" as a filter coefficient of the pixel of interest, means for multiplying the pixel of interest and the pixels adjoining the pixel of interest of an input multi-level image signal by the filter coefficients respectively, and means for outputting a sum thereof as a filter correction value; correcting means for calculating and processing the filter correction value; binarizing means for binarizing an output signal of the correcting means; a subtraction circuit for calculating a subtraction value between an output signal of the binarizing means and the output signal of the correcting means; and correction value calculating means for multiplying subtraction values of pixels adjoining a pixel to be binarized which are already outputted from the subtraction circuit by predetermined coefficients, and for outputting resultants to the correcting means.
Claim 37
Dependent Claim
209 words
An image signal processing apparatus comprising: an edge emphasizing filter including means for inputting a positive value "A" and a negative value "-B" as filter coefficients to emphasize edges in an image, means for using the input value "A" as filter coefficients of pixels adjoining a pixel of interest in main and sub scanning directions, means for using the input value "-B" as filter coefficients of pixels adjoining the pixel of interest in inclined directions, means for using a value "1+4B-4A" as a filter coefficient of the pixel of interest, means for multiplying the pixel of interest and the pixels adjoining the pixel of interest of an input multi-level image signal by the filter coefficients respectively, and means for outputting a sum thereof as a filter correction value; correcting means for calculating and processing the filter correction value; binarizing means for binarizing an output signal of the correcting means; a subtraction circuit for calculating a subtraction value between an output signal of the binarizing means and the output signal of the correcting means; and correction value calculating means for multiplying subtraction values of pixels adjoining a pixel to be binarized which are already outputted from the subtraction circuit by predetermined coefficients, and for outputting resultants to the correcting means.
Claim 38
Dependent Claim
35 words
The image signal processing apparatus of claim 24, wherein the binarizing means comprises a binarizing decoder for calculating a binary level from a sign bit and higher bits of data outputted from the correcting means.
Claim 39
Dependent Claim
175 words
An image signal processing apparatus comprising: an edge emphasizing filter including means for inputting a positive value "A" and a negative value "-B" as filter coefficients to emphasize edges in an image, means for using the input value "A" as filter coefficients of pixels adjoining a pixel of interest in main and sub scanning directions, means for using the input value "-B" as filter coefficients of pixels adjoining the pixel of interest in inclined directions, means for using a value "1+4B-4A" as a filter coefficient of the pixel of interest, means for multiplying the pixel of interest and the pixels adjoining the pixel of interest of an input multi-level image signal by the filter coefficients respectively, and means for outputting a sum thereof as a filter correction value; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; and a binarizing comparator for comparing a dither pattern outputted from the dither pattern generating circuit and the filter correction value to determine a binary level of the pixel of interest.
Claim 40
Dependent Claim
175 words
An image signal processing apparatus comprising: an edge emphasizing filter including means for inputting a positive value "A" and a negative value "-B" as filter coefficients to emphasize edges in an image, means for using the input value "A" as filter coefficients of pixels adjoining a pixel of interest in main and sub scanning directions, means for using the input value "-B" as filter coefficients of pixels adjoining the pixel of interest in inclined directions, means for using a value "1+4B-4A" as a filter coefficient of the pixel of interest, means for multiplying the pixel of interest and the pixels adjoining the pixel of interest of an input multi-level image signal by the filter coefficients respectively, and means for outputting a sum thereof as a filter correction value; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; and a binarizing comparator for comparing a dither pattern outputted from the dither pattern generating circuit and the filter correction value to determine a binary level of the pixel of interest.
Claim 41
Dependent Claim
174 words
An image signal processing apparatus comprising: an edge emphasizing filter including means for inputting a positive value "A" and a negative value "-B" as filter coefficients to emphasize edges in an image, means for using the input value "A" as filter coefficients of pixels adjoining a pixel of interest in main and sub scanning directions, means for using the input value "-B" as filter coefficients of pixels adjoining the pixel of interest in inclined directions, means for using a value "1+4B-4A" as a filter coefficient of the pixel of interest, means for multiplying the pixel of interest and the pixels adjoining the pixel of interest of an input multi-level image signal by the filter coefficients respectively, and means for outputting a sum thereof as a filter correction value; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; an adder for adding a dither pattern outputted from the dither pattern generating circuit and the filter correction value; and binarizing means for binarizing an output signal of the adder.
Claim 42
Dependent Claim
174 words
An image signal processing apparatus comprising: an edge emphasizing filter including means for inputting a positive value "A" and a negative value "-B" as filter coefficients to emphasize edges in an image, means for using the input value "A" as filter coefficients of pixels adjoining a pixel of interest in main and sub scanning directions, means for using the input value "-B" as filter coefficients of pixels adjoining the pixel of interest in inclined directions, means for using a value "1+4B-4A" as a filter coefficient of the pixel of interest, means for multiplying the pixel of interest and the pixels adjoining the pixel of interest of an input multi-level image signal by the filter coefficients respectively, and means for outputting a sum thereof as a filter correction value; a dither pattern generating circuit for outputting a signal in synchronism with the input image signal; an adder for adding a dither pattern outputted from the dither pattern generating circuit and the filter correction value; and binarizing means for binarizing an output signal of the adder.
Claim 43
Dependent Claim
137 words
An image signal processing apparatus comprising: correcting means for correcting input image data in accordance with a corrective value; binarizing means for binarizing an output signal of the correcting means; subtracting means for calculating a difference value between an output signal of the binarizing means and the output signal of the correcting means; memory means for memorizing difference values outputted from the subtracting means as error values corresponding to a pixel of interest and pixels adjoining the pixel of interest; and calculating means for reading out the error values corresponding to the pixels adjoining the pixel of interest from the memory means, for multiplying the readout error values by predetermined coefficients respectively, and for calculating a sum thereof and outputting an error correction value to the correcting means, the error correction value being equal to the sum.
Claim 44
Dependent Claim
137 words
An image signal processing apparatus comprising: correcting means for correcting input image data in accordance with a corrective value; binarizing means for binarizing an output signal of the correcting means; subtracting means for calculating a difference value between an output signal of the binarizing means and the output signal of the correcting means; memory means for memorizing difference values outputted from the subtracting means as error values corresponding to a pixel of interest and pixels adjoining the pixel of interest; and calculating means for reading out the error values corresponding to the pixels adjoining the pixel of interest from the memory means, for multiplying the readout error values by predetermined coefficients respectively, and for calculating a sum thereof and outputting an error correction value to the correcting means, the error correction value being equal to the sum.
Claim 45
Dependent Claim
149 words
An image signal processing apparatus comprising: correcting means for correcting input image data in accordance with a corrective value; binarizing means for binarizing an output sign of the correcting means; subtracting means for calculating a difference value between an output signal of the binarizing means and the output signal of the correcting means; error distributing means for making difference values outputted from the subtracting means into correspondence with a pixel of interest and pixels adjoining the pixel of interest, for multiplying the difference values by predetermined coefficients to generate errors respectively, and for outputting the errors for the respective pixels adjoining the pixel of interest; and calculating means for sequentially correcting and adding an output signal of the error distributing means in correspondence with the respective pixels adjoining the pixel of interest to generate an error correction value, and for outputting the error correction value to the correcting means.
Claim 46
Dependent Claim
149 words
An image signal processing apparatus comprising: correcting means for correcting input image data in accordance with a corrective value; binarizing means for binarizing an output sign of the correcting means; subtracting means for calculating a difference value between an output signal of the binarizing means and the output signal of the correcting means; error distributing means for making difference values outputted from the subtracting means into correspondence with a pixel of interest and pixels adjoining the pixel of interest, for multiplying the difference values by predetermined coefficients to generate errors respectively, and for outputting the errors for the respective pixels adjoining the pixel of interest; and calculating means for sequentially correcting and adding an output signal of the error distributing means in correspondence with the respective pixels adjoining the pixel of interest to generate an error correction value, and for outputting the error correction value to the correcting means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-03-12 | 1999-09-11 | 2000-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-12 | 2003-09-11 | 2004-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-12 | 2007-09-11 | 2008-03-12 | $7700.00 | Window Closed / Lapsed |