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Claims  |
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What is claimed is:
1. In an information print system having information process equipment for
treating information, including text and graphics, and print equipment
connected to said information process equipment, the information print
system comprising:
print image description means in said information equipment for developing
and describing print data for a print image and a compression means in
said information equipment for compressing said described print image
data, and
extension means in said print equipment for extending said compressed print
image data and correction means in said print equipment for correcting
said print image data to be suitable to a printing characteristic of said
print equipment,
further including plural first halftoning means and an image segmentation
means for selecting suitable data among data which are tone processed
through said plural first halftoning means.
2. An image processing apparatus which comprises:
image processing means for carrying out an image process on compressed
image data, for each of a plurality of predetermined image areas, said
image processing means being responsive to a color data signal including a
specific information for specifying at least one color which is used to
express said predetermined image and a color selection data signal
including selection information for selecting said specific information
among said color data signal as to each pixel in a predetermined image
area, and
extension means for extending to a continuous tone image data per said
pixel unit by adding color data, which is specified by said specific
information included in said color data signal of said compressed image
data which is selected by selection data, in accordance with said
selection data of each pixel in a predetermined image area which is
included in a color selection data signal of said compressed image data.
3. An image processing apparatus according to claim 2, the image processing
apparatus characterized in that,
said image processing means carries out in parallel a process for carrying
out said color data signal and a process for carrying out said color
selection data signal.
4. An image processing apparatus according to claim 2, the image processing
apparatus characterized in that,
said image processing means has a color selection data signal process means
which carries out a rotation of said image or an enlargement of said image
and a reduction of said image by altering an arrangement of said selection
information of each pixel included in said color selection data signal.
5. An image processing apparatus according to claim 2, the image processing
apparatus characterized in that,
said color data signal has color data as said specific information, and
said image processing means has color data signal process means for
carrying out a color correction process on said color data included in
said color data signal.
6. An image processing apparatus according to claim 2, the image processing
apparatus characterized in that,
said color data signal indicates a color pallet number for specifying said
color data from a color pallet table which has plural color data as said
specific information, and
said image processing means has a color pallet table process means for
carrying out a color correction process on said color data included in
said color pallet table.
7. An image processing apparatus according to claim 5 or claim 6, wherein,
said color correction process is a color conversion process.
8. An image processing apparatus according to claim 5 or claim 6, wherein,
said color correction process is a gamma correction process.
9. An image processing apparatus according to claim 2, which further
comprises a characteristic point judgment means for judging a
characteristic of a corresponding pixel to be processed by searching a
shade of the color of the pixel to be processed and a pixel which exists
at a surrounding portion of said corresponding pixel on the basis of
continuous tone image data per pixel unit which is extended by said
extension means, and a halftone process means for outputting said extended
continuous tone image data provided by said extension means, on which is
performed a halftone process in response to a judgment result of said
characteristic point judgment means.
10. An image processing apparatus according to claim 2, wherein
said color data signal has color data as said specific information, and
the apparatus further comprises characteristic point judgment means for
judging a characteristic of a corresponding pixel to be processed by
searching a shade of the color of the subject pixel and a pixel which
exists at a surrounding portion of said corresponding pixel on the basis
of color data included in said color data signal and a continuous tone
image data per pixel unit which is extended by said extension means, and a
halftone process means for outputting said extended continuous tone image
data provided by said extension means, on which is performed a halftone
process in response to a judgment result of said characteristic point
judgment means.
11. An image processing apparatus according to claim 9 or claim 10, further
comprising,
halftone reproduction means having at least two halftone process means for
carrying out a different halftone process on said continuous tone image
data per pixel which is extended by said extension means, and a selector
for selecting one among said at least two halftone process means in
response to a judgment result of said characteristic point judgment means.
12. An image processing apparatus according to claim 11, wherein
said characteristic point judgment means judges, in a case where said pixel
to be processed is denser than a pixel which exists in a surrounding
portion of said corresponding pixel, as a characteristic point of said
corresponding pixel, and
said selector changes over said halftone process means for selecting in
response to whether said pixel to be processed is judged as said
characteristic point or not.
13. An image processing apparatus according to claim 12, wherein
one of said at least two halftone process means is a smoothing process
means, and
said selector selects said continuous tone image data of said corresponding
pixel which is subjected to a smoothing process by said smoothing process
means.
14. A printer comprising an image formation unit for forming a print image
and an image process unit for outputting a signal for forming said print
image to said image formation unit, wherein
said image formation unit comprises:
storing means for storing compressed image data which comprises, for each
one of a plurality of predetermined image areas, a color data signal
including specific information for specifying at least one color for use
to express said predetermined image area, with respect to each pixel in
said predetermined image area, and a color selection data signal including
selection information for selecting said specific information among said
color data signals;
image processing means for carrying out an image process by reading out
said compressed image data stored in said storing means;
extension means for extending said compressed image data, on which is
performed said image process by said image processing means, to continuous
tone image data, by adding color data specified as specific information
included in said color data signal of said compressed image data which is
selected by said selection information for every image in accordance with
selection information of each pixel in said predetermined image area
included in said color selection data signal of said compressed image
data; and
outputting means for outputting a signal for forming said print image to
said image formation unit according to continuous tone image data which is
extended by said extension means.
15. A printer according to claim 14, characterized in that,
said image processing means has a color selection data signal process means
which carries out a rotation of said image or an enlargement of said image
and a reduction of said image by altering an arrangement of said selection
information of each pixel included in said color selection data signal.
16. A printer according to claim 14, characterized in that,
said color data signal has color data comprised of R, G, and B data as said
specific information, and
said image processing means has color conversion process means for
converting said color data included in said color data signal from said R,
G, and B data to Y, M, C, and K data.
17. A printer according to claim 14, characterized in that,
said color data signal has color data as said specific information, and
said image processing means has gamma correction means for carrying out a
gamma correction of said color data included in said color data signal
suit to a characteristic of said image formation unit.
18. A printer according to claim 14, further comprising characteristic
point judgment means for judging a characteristic of a corresponding pixel
to be processed by determining the density of the color of a pixel to be
processed and a pixel which exists at a surrounding portion of said pixel
to be processed on the basis of continuous tone image data per pixel unit
which is extended by said extension means, and a halftone process means
for outputting said extended continuous tone image data provided by said
extension means, on which is performed a halftone process in response to a
judgment result of said characteristic point judgment means.
19. An image processing method for extending and outputting compressed
image data, the image processing method is characterized in that,
previous to an extension process of said compressed image data, an image
processing is carried on said compressed image data,
wherein said compressed image data comprises, for each of a plurality of
predetermined image areas, a color data signal including specific
information for specifying at least one color which is used to express
said predetermined image and a color selection data signal including
selection information for selecting said specific information among said
color data signal as to each pixel in said predetermined image area,
comprising the step of:
extending compressed image data by an image processing to form continuous
tone image data per said pixel unit, including adding color data which is
specified by specific information included in said color data signal of
said compressed image data, which is selected by selection data in
accordance with said selection data of each pixel in a predetermined image
area included in a color selection data signal of said compression image
data.
20. In an information print system having information process equipment for
treating information, including text and graphics, and print equipment
connected to said information process equipment, the information print
system comprising:
in said information process equipment, means for developing and describing
print data to form a print image and fixed rate compression means for
compressing said described print image data, and
in said print equipment, fixed rate extension means for extending said
compressed print image data and correction means for correcting said
extended print image data to be suitable to a printing characteristic of
said print equipment,
further including plural first halftoning means and an image segmentation
means for selecting suitable data among data which are tone processed
through said plural first halftoning means.
21. In an information print system having information process equipment for
treating information, including text and graphics, and print equipment
connected to said information process equipment, the information print
system comprising:
in said information process equipment, means for developing and describing
print data to form a print image and variable rate compression means for
compressing said described print image data, and
in said print equipment, variable rate extension means for extending said
compressed print image data and to correct said extended print image data
to be suitable to a printing characteristic of said print equipment,
further including plural first halftoning means and an image segmentation
means for selecting suitable data among data which are tone processed
through said plural first halftoning means.
22. An information print system according to one of claims 1, 20 and 21,
further including tone expression means, and second halftoning means which
differs from said first halftoning means. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
The present invention relates to an information print system and an image
processing apparatus wherein in an information process equipment such as a
personal computer a data for carrying out a print is processed to make
electronically and in a print equipment or an image outputting apparatus
such as a printer under a basis of an obtained electronically data a print
is carried out on a print recording paper etc.
In a prior art, as a printer for printing a data which is processed in a
personal computer etc., there are various kinds of printers and in which
so as to carry out a high speed and a high quality print, a laser printer
is most suited. And recently, in place of the monochrome printers, much
color laser printers are manufactured and a demand for the color laser
printers increases remarkably.
However, in the color laser printer, in generally PDL (a page description
language) using a general use interface is employed, at a side of a
printer, there is a problem in which a construction of a print control
unit for carrying out a data control becomes complicated one and also
becomes high in a cost aspect.
Therefore, it is attempted that a printed data is described at a side of
the personal computer and this described data is sent to a side of a
printer, as a result a low cost information print system is realized.
Since a commercial price of a printer engine can be reduced, the above
stated information print system can be expected for a large demand in
future.
However, in a method for sending the described data to the printer, a
process reduction and a simplification of a control unit of the printer
can be improved, there is a problem in which since a load at the side of
the personal computer becomes large and also a transmission data becomes
large, in comparison with PDL (the page description language), it will
take a comparative large print time.
As stated in above, at the side of the personal computer, in the method for
describing the print data and sending the described data, the burden for
the personal computer is larger than in comparison with PDL (the page
description language). However, since a performance of the recent personal
computer is improved extremely remarkably, as a whole print system, a rate
for occupying for a process time of the personal computer itself is
lessened.
However, in the case of the color laser print, since an amount of a print
image data for transmitting from the personal computer to the color laser
printer is large, in the event of the improvement in performance for the
personal computer, it can not reach to attain a large time shortening.
To attain the time shortening, there is a problem in which how a data
transmission amount of the print image data for sending from the personal
computer to the printer is made small, and to carry out a high quality
print, it will be contrary to the above stated requirement in reduction of
the data transmission amount.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an information print
system and an image processing apparatus wherein a transmission time of a
print image data can be shortened and a print time can be shortened and a
high quality print for suiting a printing characteristic of a printer can
be obtained.
The essential features of the information print system and the image
processing apparatus according to the present invention can be realized by
providing a data compression means for compressing a transmission data at
a side of an information equipment such as a personal computer and
providing a data extension means for extending a compressed data at a
print equipment and the data transmission between said information
equipment and said print equipment is carried out giving and taking by
said compressed data.
Further, with respect to the compression process and the extension process,
by providing a fixed rate compression process and extension means and a
variable rate compression process and extension means, and it can be
realized according to a combination therebetween.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a view showing a concept of a whole print motion of an
information print system and an image processing apparatus according to
the present invention;
FIG. 2 is a view showing a whole construction of an information print
system and an image processing apparatus according to the present
invention;
FIG. 3 is a flow chart showing an approximation coding compression motion
of a block;
FIG. 4 is a view showing a position on a color space of an approximation
coding compression motion of a block;
FIG. 5 is a view showing a data style of an approximation coding
compression motion of a block;
FIG. 6 is a view showing an extension circuit of an approximation coding
compression motion of a block;
FIG. 7 is a view showing a conversion of a color correction process;
FIG. 8 is a view showing a conversion of a color conversion process;
FIG. 9 is a view showing a conversion of a gamma correction process;
FIG. 10 is a view showing a motion of a first halftoning process;
FIG. 11 is a view showing a motion of an image area segmentation process;
FIG. 12 is a flow chart showing a print motion of a personal computer;
FIG. 13 is a view showing a condition display screen during a print
process;
FIG. 14 is a view showing an unit for carrying out a variable rate
compression after an approximation coding compression of a block;
FIG. 15 is a view showing a data construction which is transmitted to a
color laser printer;
FIG. 16 is a flow chart showing a print motion of a color laser printer;
FIG. 17 is a view and a flow chart showing a print about a rotation of an
approximation compression coding data of a block;
FIG. 18 is a schematic view for explaining another embodiment of a printer
of an information print system and an image processing apparatus according
to the present invention;
FIG. 19 is a view for explaining a construction example of a compressed
image data in a case where colors in a predetermined image area are
truncated to plural colors by an execution in which a color space is taken
into a consideration;
FIG. 20 is a view for explaining a generation process of a color data
signal of a compression image data shown in FIG. 19;
FIG. 21 is a construction block view showing a print control unit 11B shown
in FIG. 18;
FIG. 22 is a construction block view showing a color data signal execution
unit 161B shown in FIG. 21;
FIG. 23 is a schematic block view showing a color judgment unit 163B and a
characteristic point judgment unit 164B shown in FIG. 21;
FIG. 24 is a view for explaining a flow of a process in the color judgment
unit 163B and the characteristic point judgment unit 164B shown in FIG. 21
in a case where color data included in a color data signal are two;
FIG. 25 is a view showing a flow of a detail process according to the color
judgment unit 163B shown in FIG. 24;
FIG. 26 a view for explaining a flow of a process in the color judgment
unit 163B and the characteristic point judgment unit 164B shown in FIG. 21
in a case where color data included in a color data signal are four;
FIG. 27 is a view for explaining a flow of a detail process according to a
color difference execution unit 163aB of the color judgment unit 163B
shown in FIG. 26;
FIG. 28 is a view for explaining a flow of a detail process according to a
shade judgment unit 163bB of the color judgment unit 163B shown in FIG.
26;
FIG. 29 is a view for explaining another shade judgment method in a case
where four color data are included in a color data signal;
FIG. 30 is a construction block view of an halftone process unit 17B shown
in FIG. 21;
FIG. 31 is a view for explaining a modified embodiment of the first
embodiment of the information print system and the image processing
apparatus according to the present invention shown in FIG. 18;
FIG. 32 is a circuitry construction of a print control unit to which the
first embodiment of the information print system and the image processing
apparatus according to the present invention is applied;
FIG. 33 is a view for explaining a construction example of a compression
image data in a case where a color in a predetermined image area truncated
to plural colors using a color pallet table;
FIG. 34 is a view for explaining a generation process of a color data
signal of a compressed image shown in FIG. 33;
FIG. 35 is a construction block view showing a print control unit 11aB
which is an essential unit according to the present invention;
FIG. 36 is a construction block view showing an extension unit 14aB shown
in FIG. 35; and
FIG. 37 is a circuitry construction showing a display control unit 70B to
which the present invention is applied.
DESCRIPTION OF THE PRESENT INVENTION
Hereinafter, one embodiment of an information print system and an image
processing apparatus according to the present invention will be explained
in detail referring to the drawings.
In this embodiment of the information print system and the image processing
apparatus according to the present invention, a personal computer is
explained as an information processing equipment and a color laser printer
will be explained as an outputting apparatus. First of all, the
constructions of the personal computer and the color laser printer will be
explained referring to FIG. 2.
A personal computer 20A is constituted by an input unit 1A such as a
keyboard and a mouse, a display unit 2A such as a CRT for displaying a
text and a graphics, a memory unit 3A such as a semiconductor memory for
storing such as a data and a control program about a document, an external
memory unit 4A such as a hard disc, a communication unit 5A such as a
centronics for carrying out a communication with a color laser printer
21A, and a control unit 6A for carrying out various controls using a
microprocessor etc. by various programs which have installed in an inside
portion thereof.
The control unit 6A is constituted by an input control unit 61A for
transmitting an input information of the input unit 1A to a request party,
a display control unit 62A for developing the text and the graphics which
are displayed on the display unit 2A, a communication control unit 63A for
controlling the communication unit 5A, a print control unit 64A for
preparing a print image data by describing the text and the graphics to be
indicated to print and for transmitting the print image to the color laser
printer 21A, a file control unit 65A for preparing a file to the external
memory unit 4A and for reading out and writing in of the file, and an
application unit 66A for indicating a display a document data to the
display control unit 62A and for indicating the print to the print control
unit 64A.
On the other hand, the color laser printer 21A is constituted by a memory
unit 7A such as a semiconductor memory for storing the print image data
etc. which are transmitted from the control program and the personal
computer 20A, a communication unit 8A such as a centronics etc. for
carrying out the communication with the personal computer 20A, a printer
control unit 9A such as a LSI etc. which assist a function of a
communication control unit 91A and a data control unit 92A for controlling
the communication unit 8A, and a printer engine 10A for executing a paper
feed, a paper print, and a paper exit of a recording paper.
The printer control unit 9A is constituted by the communication control
unit 91A for storing the printer image data to the memory unit 7A by
controlling the communication unit 8A, the data control unit 92A for
converting a data which can print the received print image data in the
printer engine 10A, and an engine control unit 93A for carrying out a
control of a mechanical component which carries out a process of the paper
feed, the paper print and the paper exit of the printer engine 10A.
Further, the personal computer 20A and the color laser printer 21A are
connected through a printer cable 22A.
Next, a process summary during a color print process of the information
print system and the image processing apparatus will be explained
referring to FIG. 1 and in the personal computer 20A following processes
are carried out.
Namely, against to the print indication of the text and the graphics from
the application unit 66A, in the print control unit 64A the text and the
graphics are developed to a print use color image. In this case, in a
print image development unit 641A, red, green, and blue (hereinafter, they
are expressed by R, G, and B) are developed a color continuous tone data
having 256 tones (a color multi-valued digit data having 256 gradations).
Next, during a development finish of a data corresponding to one page part,
in a data compression unit 642A a data compression is carried out and the
compressed data is transmitted to the color laser printer 21A. Herein, the
data compression uses a block approximation coding compression of a fixed
rate compression method and MH (Modify Hofmann) compression of a variable
rate compression method.
On the other hand, in the color laser printer 21A, a compressed data, which
is received in the data process unit 92A, is extended at a data extension
unit 921A.
Next, after a color of the extended data is corrected at a color correction
unit 922A in a color space of the printer, at a color conversion process
unit 923A, R, G, and B are converted to three primary colors of yellow,
magenta, and cyan. And after that a generation process (BG) of a black
component and an under color removal (UCR) process of the black color are
carried out and they are converted to the actual print colors comprised of
yellow, magenta, cyan, and black (hereinafter, they are called as Y, M, C,
and K).
Next, suiting to the characteristic of the printer, at a gamma correction
unit 924A, an adjustment of a tone intensity is carried out by separating
the print color each, at a first halftoning unit 925A, every the print
color each, according to a condition, they are converted to values of
three pulse widths of an "on edge", a "near edge", and a "flat (not
edge)".
Next, at an image area segmentation unit 926A, a condition of pixel (the
"on edge", the "near edge", and the "flat (not edge)") is judged and a
pulse width value of the first halftoning unit 925A is selected, at a
second halftoning unit 927A, a pulse width according to a pulse width
value is outputted to the printer engine 10A and one dot is expressed to a
continuos tone (a multi-valued gradation) and the print is carried out.
Further, these processes are carried out by synchronizing a data which
outputs to the printer engine control unit 93A and a series of the
processes is carried out repeatedly and consequently the print about one
page part is carried out.
Further, the process contents of the color correction unit 922A, the color
conversion process unit 923A, the gamma correction unit 924A, and the
image area segmentation unit 926A are varied in accordance with an
indication of a color process indication unit 643A of the personal
computer 20A. For example, in the color laser printer 21A, since plural
process are provided in advance, it is sufficient to indicate a number of
the process. Further, in a case where the process content which is not
provided in the color laser printer 21A is indicated, it is sufficient to
transmit a table for expressing the process content etc. from the personal
computer 20A.
Next, concrete essential factor techniques of this embodiment of the
information print system and the image processing apparatus according to
the present invention will be explained.
(1) Block Approximation Coding Compression Process and Extension Process
A block approximation coding compression works a role in which a color
continuous tone data about a whole one page part is divided into a small
rectangle block (for example, such as 8.times.8 pixel, 4.times.4 pixel,
etc.) and a data of the respective block is compressed.
Next, the block approximation coding compression in this block will be
explained by taking an example in which a block comprising 4.times.4 pixel
is truncated to two colors and using a flow chart shown in FIG. 3 and a
view showing the pixel arrangement shown in FIG. 4 and also a view showing
the data style shown in FIG. 5.
First of all, as shown in FIG. 4(A), R, G, and B of the pixel in one block
are taken and a color having the maximum amplitude is requested, and as
shown in a quadrangle shown in a broken line of FIG. 4(B), an intermediate
value of an amplitude range of the color having the maximum amplitude is
requested, and further as shown with .smallcircle., .circle-solid. in FIG.
4(B), using a relative size relationship to the intermediate value, they
are classified into two groups.
Next, as shown with .quadrature., .box-solid. in FIG. 4(B), an average
value of the respective group is haven an approximation color of the group
and finally a group attribute of each pixel (a selection information for
using which approximation color is one bit per one pixel) and an
approximation color is outputted.
The above stated process is carried out in the print control unit 64A using
the flow chart shown in FIG. 3.
As to the data style, for example, in a case where it is truncated as shown
in FIG. 5(A), the data about R, G, and B is 256 tones (gradations) and is
one bite each, and as shown in FIG. 5(B), as against to an original data
is 48 bites, a compressed data is 8 bites and as a result a compression
rate is 1/6.
Further, in a case where 8.times.8 pixel block is truncated to two colors,
as shown in FIG. 5(C), as against an original data is 192 bites, a
compressed data is 14 bites, and as a result compression rate is 7/96. As
understood from the above stated example, in a case of the same number of
the approximation color, the pixel number of the block is made larger, a
compression effect is further heightened.
Herein, since the block approximation coding compression has not a
reversibility property, according to circumferences a picture quality may
change. However, a case where only two colors are used, (for example, on a
background having the same color, and a text having a separate and another
same color exists), it has a feature that the picture quality is not
entirely change and this does not appear in a general fixed rate
compression system.
On the other hand, with respect to an extension of the block approximation
coding compression data, according to a selection information only it is
converted either of the two approximation colors. Since the data extension
unit 921A can be realized using a simple circuitry as shown in FIG. 6, the
extension process can be carried out by synchronizing the data which
output to the printer engine control unit 93A.
With the above stated process, the data after the extension process is
unnecessary to store using enormous memories, a memory construction having
a small capacity can be attained.
(2) Color Correction Process
A color correction process is that the color space of an original data is
divided into small blocks in which, for example, the color space is
divided equally into 16 parts with respect to a respective axis, and a
color correction table for storing a coordinate after the correction of
the respective apex of the small blocks is prepared.
The color correction process in the block is carried out by referring to
the above color correction table, and thus, as shown in FIG. 7, the color
correction process is carried out. This color correction process is
carried out using following color correction conversion formula and a
linear correction process is carried out.
Color correction formula:
R=e.times.{c.times.(a.times.Q1R+b.times.Q2R)+d.times.(a.times.Q3R+b.times.Q
4R)+f.times.{c.times.Q5R+b.times.Q6R)+d.times.(a.times.Q7R+b.times.Q8R)}
G=e.times.{c.times.(a.times.Q1G+b.times.Q2G)+d.times.(a.times.Q3G+b.times.Q
4G)+f.times.{c.times.Q5G+b.times.Q6G)+d.times.(a.times.Q7G+b.times.Q8G)}
B=e.times.{c.times.(a.times.Q1B+b.times.Q2B)+d.times.(a.times.Q3B+b.times.
Q4B)+f.times.{c.times.Q5B+b.times.Q6B)+d.times.(a.times.Q7B+b.times.Q8B)}
Herein, (a, b), (c, d), (e, f) are a respective interior division ratio;
(Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8) are a respective mapping correspondence
point;
Q1R-Q8R is a R component of the respective mapping correspondence point;
Q1G-Q8G is a G component of the respective mapping correspondence point;
and
Q1B-Q8B is a B component of the respective mapping correspondence point.
Variations of the above stated conversion formula:
R=(a.times.c.times.e.times.Q1R)+(b.times.c.times.e.times.Q2R)+(a.times.d.ti
mes.
e.times.Q3R)+(b.times.d.times.e.times.Q4R)+(a.times.c.times.f.times.Q5R)+(
b.times.c.times.f.times.Q6R)+(a.times.d.times.f.times.Q7R)+(b.times.c.times
.f.times.Q8R)
G=(a.times.c.times.e.times.Q1G)+(b.times.c.times.e.times.Q2G)+(a.times.d.ti
mes.
e.times.Q3G)+(b.times.d.times.e.times.Q4G)+(a.times.c.times.f.times.Q5G)+(
b.times.c.times.f.times.Q6G)+(a.times.d.times.f.times.Q7G)+(b.times.c.times
.f.times.Q8G)
B=(a.times.c.times.e.times.Q1B)+(b.times.c.times.e.times.Q2B)+(a.times.d.t
imes.
e.times.Q3B)+(b.times.d.times.e.times.Q4B)+(a.times.c.times.f.times.Q5B)+(
b.times.c.times.f.times.Q6B)+(a.times.d.times.f.times.Q7B)+(b.times.c.times
.f.times.Q8B)
By the contents of these color correction tables are varied and the color
correction process can be altered.
Further, since a coefficient of a multiplication (three multiplication
efficient using a, b, c, d, e, f) of the each color is not depended to the
contents of the color correction tables, by preparing a color correction
efficient table, it can be attained a high speed process.
(3) Color Conversion Process
In a color conversion process, the data of R, G, and B is converted to
three primary color for the print which are Y=255-B, M=255-G, and C=255-R,
and next a conversion process about the generation of the black component
and the under color removal of the black component is carried out
referring to a black generation (BG) table and the under color removal
(UCR) table (Y, M, and C has a respective separate table) as shown in FIG.
8. The conversion formula are as following.
Conversion formula:
K=Ka
Y=Y-YKa
M=M-MKa
C=C-CKa
Further, by altering the contents of the respective table, the process
content can be altered.
(4) Gamma Correction Process
The gamma correction process is carried out to convert referring to a gamma
table of a respective and separate color as shown in FIG. 9. The
conversion formula are as following.
Conversion formula:
K=K.gamma.(K)
Y=Y.gamma.(Y)
M=M.gamma.(M)
C=C.gamma.(C)
Further, by altering the content of the respective table, the process
content can be altered.
(5) First Halftoning Process
With respect to an "on edge" unit, a sharpness of the edge of the text and
the line is emphasized by setting only a high rank 4 bits to a pulse width
value as shown in FIG. 10(A). With respect to a "flat (not edge)" unit, to
heighten a reproduction property, a screen angle of a dither matrix of a
net type of each color is changed, as a result a sharp picture in which a
miss color registration can be outputted.
Further, a process content about a concrete one pixel, as shown in FIG.
10(B), when a difference part (a tone intensity of an input data dither
matrix at a correspondence position) is more than a predetermined value, a
maximum pulse width value (15) is set and on the other hand when the
difference part is less than 0 (zero), a pulse width value 0 (zero) is
set, and except for the above cases the difference part is set to the
pulse width value.
Further, with respect to a "near edge" unit, using a dither matrix shown in
FIG. 10(B) in which a dither matrix has a halftone expression of the both,
as a result a pulse width value is set.
(6) Image Area Segmentation Process
Relating to one pixel unit every color each, referring to a condition of a
pixel at a vicinity as shown in a flow chart of FIG. 11(A), one condition
is selected from three conditions (the "on edge", the "near edge", and the
"flat (not edge)").
In concretely, in a case where P22 shown in FIG. 11(B) is a subjective to
be judged, using a filter execution, Z (Z=4P22-P11-P13-P33) is requested,
and when an absolute value of Z is larger than a certain threshold value,
it judges as the "on edge". Next, the pixel, which is judged as the edge
at a vicinity at a range of one pixel of P22, is more than one, in such
case it judges as the "on edge".
Next, the pixel, which is judged as the edge at a vicinity at a range of
two pixels of P22, is more than one, in such case it judges as the "near
edge". Except for the above two cases, it judges as the "flat (not edge)".
One among three pulse width values which is requested by the first
halftoning corresponding to this judgment result is outputted.
(7) Second Halftoning Process
Using a pulse width value (16 levels comprised from 0 to 15) which is
selected in the image area segmentation, the pulse width is outputted to
the printer engine 10A and one pixel is expressed by the continuous tone.
Further, when the pulse width is made large, the more many laser light
strikes and the more charging amount obtains, accordingly a dimension
about one pixel is made thick at a primary scanning direction.
Next, a print motion about one page of the information print system and the
image processing apparatus according to the present invention will be
explained in detail. First of all, a motion about the personal computer
20A will be explained using flow charts shown in FIG. 12(A) and FIG.
12(B).
When the print is indicated, the personal computer 20A carries out a
display and a selection of setting items of a print condition to a display
apparatus of the personal computer 20A.
The setting items of the print condition are the color print, a high
resolution, the color correction, the gamma correction, a dither etc. and
in case of a designation for the color print a following process is
carried out.
A parameter of the color process designation etc. shown in FIG. 13 is
stored to a file as a parameter information which is a style shown in FIG.
15(A). In a case where the high resolution print is designated, a print
image about one page part having a color continuous tone data of 600 dpi
is prepared, on the other hand in a case where the high resolution print
is not designated, a print image about one page part having a color
continuous tone data of 300 dpi is prepared.
In the case of the color continuous tone data of 300 dpi, since a data
capacity is small in comparison with the color continuous tone data of 600
dpi, a fixed rate compression of a two color approximation of 4.times.4
pixel block having a small compression effect is carried out. In this
case, the compression rate is 1/6.
On the other hand, in the case of the color continuous tone data of 600
dpi, since a data capacity is large, at a standard condition of a memory
capacity of the memory unit 7A of the color laser printer 21A, a fixed
rate compression of a two color approximation of 8.times.8 pixel block
having a large compression effect is carried out. In this case, the
compression rate is 7/96.
Further, in a case where an extended memory is added, the compression
effect is small but the fixed rate compression of the two color
approximation of 4.times.4 pixel block having a small inferior picture
quality is carried out. Herein, an example where a dimension of the pixel
block is altered is shown, however it is possible to use four colors of a
number of the approximation colors by making the same the dimension of the
pixel block.
Next, the data after the fixed rate compression is carried out a variable
rate compression (Modify Hofmann (MH) compression) at every block line
each as shown in FIG. 14, in this time in a case where the capacity of the
above stated data is larger than that of the origina | | |
