Image formation device with binary/halftone pixel determination

Claim 2

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: matrix formation means for forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; pixel identification means for determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; first conversion means for converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification means; second conversion means for converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification means; and synthesizing means for synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the pixel identification means including: first determination means for determining whether each pixel signal in the data matrix window is a binary or a halftone; and second determination means for determining whether the objective pixel is a binary or a halftone using the determination results obtained by the first determination means.

Claim 3

The image formation device as set forth in claim 1, wherein the second determination means operates in such a way that the objective pixel is determined to be a halftone if the objective pixel is not binary or if the objective pixel is a binary and no binary pixel is included in surrounding pixels, and the objective pixel is determined to be a binary if the objective pixel is a binary and at least one binary is included in surrounding pixels.

Claim 4

The image formation device as set forth in claim 1, wherein the second determination means operates in such a way that the objective pixel is determined to be a halftone if the objective pixel is not binary or if the objective pixel is a binary and at least one halftone pixel is included in surrounding pixels, and the objective pixel is determined to be a binary if the objective pixel is a binary and no halftone is included in surrounding pixels.

Claim 5

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: matrix formation means for forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; pixel identification means for determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; first conversion means for converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification means; second conversion means for converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification means; and synthesizing means for synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the binarization processing in the first conversion means including smoothing such that the pulse width of the pulse signal is adjusted to smooth a jagged appearance of an outline if the objective pixel is on the outline.

Claim 6

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: matrix formation means for forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; pixel identification means for determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; first conversion means for converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification means; second conversion means for converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification means; and synthesizing means for synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the binarization processing in the first conversion means including smoothing such that the pulse width of the pulse signal is adjusted to smooth a jagged appearance of an outline if the objective pixel is on the outline.

Claim 7

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, a method of forming the image signal based on input pixel signals each having a predetermined number of bits, the method comprising the steps of: forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary; converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone; and synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the step of determining whether the objective pixel is a binary or a halftone, further including: a first step of determining whether each pixel signal in the data matrix window is a binary or a halftone; and a second step of determining whether the objective pixel is a binary or a halftone using the determination results obtained by the first step.

Claim 8

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, a method of forming the image signal based on input pixel signals each having a predetermined number of bits, the method comprising the steps of: forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary; converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone; and synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the step of determining whether the objective pixel is a binary or a halftone, further including: a first step of determining whether each pixel signal in the data matrix window is a binary or a halftone; and a second step of determining whether the objective pixel is a binary or a halftone using the determination results obtained by the first step.

Claim 9

The method as set forth in claim 5, wherein the second step is that the objective pixel is determined to be a halftone if the objective pixel is not binary or if the objective pixel is a binary and no binary pixel is included in surrounding pixels, and the objective pixel is determined to be a binary if the objective pixel is a binary and at least one binary is included in surrounding pixels.

Claim 10

The method as set forth in claim 5, wherein the second step is that the objective pixel is determined to be a halftone if the objective pixel is not binary or if the objective pixel is a binary and at least one halftone pixel is included in surrounding pixels, and the objective pixel is determined to be a binary if the objective pixel is a binary and no halftone is included in surrounding pixels.

Claim 11

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, a method of forming the image signal based on input pixel signals each having a predetermined number of bits, the method comprising the steps of: forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary; converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone; and synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the binarization processing including smoothing such that the pulse width of the pulse signal is adjusted to smooth a jagged appearance of an outline if the objective pixel is on the outline.

Claim 12

In an electrophotographic printer for forming a visible image based on an image signal including a plurality of pulse signals, a method of forming the image signal based on input pixel signals each having a predetermined number of bits, the method comprising the steps of: forming a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; determining whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; converting the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary; converting the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone; and synthesizing the plurality of pulse signals generated by the first and second conversion means to form the image signal; the binarization processing including smoothing such that the pulse width of the pulse signal is adjusted to smooth a jagged appearance of an outline if the objective pixel is on the outline.

Claim 13

In an electrophotographic printer for forming visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: a matrix formation device to form a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; a pixel identification device to determine whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; a first conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification device; a second conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification device; and a synthesizing device for synthesizing the plurality of pulse signals generated by the first and second conversion devices to form the image signal; the pixel identification device including: a first determination device to determine whether each pixel signal in the data matrix window is a binary or a halftone; and a second determination device to determine whether the objective pixel is a binary or a halftone using the determination results obtained by the first determination device.

Claim 14

In an electrophotographic printer for forming visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: a matrix formation device to form a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; a pixel identification device to determine whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; a first conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification device; a second conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification device; and a synthesizing device for synthesizing the plurality of pulse signals generated by the first and second conversion devices to form the image signal; the pixel identification device including: a first determination device to determine whether each pixel signal in the data matrix window is a binary or a halftone; and a second determination device to determine whether the objective pixel is a binary or a halftone using the determination results obtained by the first determination device.

Claim 15

The image formation device as set forth in claim 9, wherein the second determination device operates in such a way that the objective pixel is determined to be a halftone if the objective pixel is not binary or if the objective pixel is a binary and no binary pixel is included in surrounding pixels, and the objective pixel is determined to be a binary if the objective pixel is a binary and at least one binary is included in surrounding pixels.

Claim 16

The image formation device as set forth in claim 9, wherein the second determination device operates in such a way that the objective pixel is determined to be a halftone if the objective pixel is not binary or if the objective pixel is a binary and at least one halftone pixel is included in surrounding pixels, and the objective pixel is determined to be a binary if the objective pixel is a binary and no halftone is included in surrounding pixels.

Claim 17

In an electrophotographic printer for forming visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: a matrix formation device to form a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; a pixel identification device to determine whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; a first conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification device; a second conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification device; and a synthesizing device for synthesizing the plurality of pulse signals generated by the first and second conversion devices to form the image signal; the binarization processing in the first conversion device including smoothing such that the pulse width of the pulse signal is adjusted to smooth a jagged appearance of an outline if the objective pixel is on the outline.

Claim 18

In an electrophotographic printer for forming visible image based on an image signal including a plurality of pulse signals, an image formation device for forming the image signal based on input pixel signals each having a predetermined number of bits, the image formation device comprising: a matrix formation device to form a data matrix window having a predetermined number of pixels in the primary scanning direction and the predetermined number of pixels in the secondary scanning direction, the data matrix window shifting successively in units of a pixel; a pixel identification device to determine whether an objective pixel at a predetermined location of the data matrix window is a binary or a halftone, based on an objective pixel signal and surrounding pixel signals in the data matrix window; a first conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by binarization processing if the objective pixel is determined to be a binary by the pixel identification device; a second conversion device to convert the objective pixel signal to a pulse signal with a pulse width obtained by halftone processing if the objective pixel is determined to be a halftone by the pixel identification device; and a synthesizing device for synthesizing the plurality of pulse signals generated by the first and second conversion devices to form the image signal; the binarization processing in the first conversion device including smoothing such that the pulse width of the pulse signal is adjusted to smooth a jagged appearance of an outline if the objective pixel is on the outline.