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| United States Patent | 5579446 |
| Link to this page | http://www.wikipatents.com/5579446.html |
| Inventor(s) | Naik; Sachin S. (San Diego, CA);
Kurucz; Frank A. (Escondido, CA) |
| Abstract | In a color printer system, an interactive user interface allows a choice
between one-"button" automatic control of color output or multibutton
control of color output, with both automatic and manual options providing
independent control for color halftoning and for color correction based on
the types of objects to be printed. The preferred form allows independent
print-rendering options for text, graphics and photo images. |
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Title Information  |
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| Publication Date |
November 26, 1996 |
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| Filing Date |
January 27, 1994 |
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| Parent Case |
RELATED APPLICATIONS
These related applications, assigned to the assignee of the present
application, are incorporated here by reference in their entirety--
Filed concurrently herewith: application Ser. No. 08/189,006, entitled
"ADAPTIVE COLOR RENDERING BY AN INKJET PRINTER BASED ON OBJECT TYPE", in
the names of Thomas G. Smith, et al.; Ser. No. 08/187,933, entitled "COLOR
HALFTONING OPTIONS INFLUENCED BY PRINT-MODE SETTING", in the names of Kirt
A. Winter et al.; Ser. No. 08/187,935, entitled "COLOR DIGITAL HALFTONING
USING COLOR VECTOR DITHERING", in the names of Alexander Perumal, Jr., et
al. and now file-wrapper continuing application Ser. No. 08/438,294; Ser.
No. 08/189,541, entitled "COLOR DIGITAL HALFTONING USING COLOR VECTOR
DITHERING AND BLACK AND SECONDARY COLOR REPLACEMENT", in the names of
Alexander Perumal, Jr., et al.; Ser. No. 08/187,567, entitled "BI-LEVEL
DIGITAL COLOR PRINTER SYSTEM EXHIBITING IMPROVED UNDERCOLOR REMOVAL AND
ERROR DIFFUSION PROCEDURES", in the names of Gary Dispoto, et al.; and
Ser. No. 08/188,618, entitled "AUTOMATED OPTIMIZATION OF HARDCOPY OUTPUT",
in the names of Steven O. Miller, et al.; and further
Earlier-filed and copending herewith: Ser. No. 08/057,244, entitled
"HALFTONE IMAGES USING PRINTED SYMBOLS MODELLING", filed May 3, 1993, in
the name of Qian Lin; and Ser. No. 08/060,285, entitled "HALFTONE IMAGES
USING SPECIAL FILTERS", filed May 11, 1993, in the name of Qian Lin. |
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Title Information |
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Description |
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RELATED APPLICATIONS
These related applications, assigned to the assignee of the present
application, are incorporated here by reference in their entirety--
Filed concurrently herewith: application Ser. No. 08/189,006, entitled
"ADAPTIVE COLOR RENDERING BY AN INKJET PRINTER BASED ON OBJECT TYPE", in
the names of Thomas G. Smith, et al.; Ser. No. 08/187,933, entitled "COLOR
HALFTONING OPTIONS INFLUENCED BY PRINT-MODE SETTING", in the names of Kirt
A. Winter et al.; Ser. No. 08/187,935, entitled "COLOR DIGITAL HALFTONING
USING COLOR VECTOR DITHERING", in the names of Alexander Perumal, Jr., et
al. and now file-wrapper continuing application Ser. No. 08/438,294; Ser.
No. 08/189,541, entitled "COLOR DIGITAL HALFTONING USING COLOR VECTOR
DITHERING AND BLACK AND SECONDARY COLOR REPLACEMENT", in the names of
Alexander Perumal, Jr., et al.; Ser. No. 08/187,567, entitled "BI-LEVEL
DIGITAL COLOR PRINTER SYSTEM EXHIBITING IMPROVED UNDERCOLOR REMOVAL AND
ERROR DIFFUSION PROCEDURES", in the names of Gary Dispoto, et al.; and
Ser. No. 08/188,618, entitled "AUTOMATED OPTIMIZATION OF HARDCOPY OUTPUT",
in the names of Steven O. Miller, et al.; and further
Earlier-filed and copending herewith: Ser. No. 08/057,244, entitled
"HALFTONE IMAGES USING PRINTED SYMBOLS MODELLING", filed May 3, 1993, in
the name of Qian Lin; and Ser. No. 08/060,285, entitled "HALFTONE IMAGES
USING SPECIAL FILTERS", filed May 11, 1993, in the name of Qian Lin.
BACKGROUND
1. Field of the Invention
This invention relates generally to color printing; and more particularly
to printing different types of color objects (or so-called "copy") in a
common printout.
2. Related Art
The use of color monitors for computers has accelerated the need for color
printers which can produce a satisfactory printout of what is displayed on
the screen. With such equipment, determining what constitutes a
"satisfactory" color printout is often quite problematic.
Part of this problem arises from the subjective nature of color. Color is a
sensation produced by the combined effects of light, objects and human
vision. A particular color or combination of colors may be appealing to
one person while at the same time being offensive to another.
Another part of the "satisfactory"-color definitional problem arises from
the different color technologies used in computer monitors and color
printers. For example, computer monitors are based on a color gamut 202
(FIG. 10) of red, green and blue pixels (RGB) whereas color printers such
as inkjet printers are typically based on a color gamut 203 of cyan,
magenta, yellow and black (CMYK). The RGB color components of computer
monitors are combined together in an "additive" way by mixing red, green
and blue light rays to form a first variety 202 of different colors; but
the CMYK components of color inks are applied to media in different
combinations in a "subtractive" way to form a second variety 203 of
different colors.
The mutually overlapping character of the two gamuts 202 and 203 compounds
the difficulty of defining what is "satisfactory": a great range of vivid
colors 205 which a monitor screen can display are physically unprintable.
Equally troublesome, a considerable range of vivid colors 204 which a
printer can print tend never to be called up, because they are physically
undisplayable by the monitor.
Various different color-management techniques have been used to provide
some form of matching between, for instance, the colors viewed on a
computer monitor and the colors printed by a specific printer using a
given ink formula on a particular type of printing medium. Such
color-management techniques have also employed different types of
halftoning algorithms (in this art commonly called "rendition" or
sometimes "rendering") to improve appearance of color printout of various
types of objects (or in traditional publications jargon "copy").
Desktop publishing software has created an additional dimension of the
satisfactory-color-definition problem by printing together, in a composite
document, objects (or "copy") of different types. Such types include
photos and photograph-like images, business graphics (e.g., charts and
logos), and scalable text in both color and black.
On one hand, by skewing the printer color output to ensure satisfactory
color printing of photos, color-management systems often cause the
business graphics in the same document to appear washed out and lose their
impact. On the other hand, by skewing the color output to ensure
satisfactory color printing of saturated vivid colors for business
graphics, color systems can cause a photo in the same document to lose its
lifelike appearance.
Some parts of the aforementioned color printing problem have been partially
solved by providing manually controlled printer settings to optimize
results. In addition, sophisticated users who demand exact color matching
from screen to printout can obtain some solutions by customizing object
specifications before incorporation into a document--using
color-management software integrated into computer operating systems, as
well as color-management software supplied as third-party software
applications.
Also, some color-matching technology has been incorporated into printer
drivers. A driver provides a translation interface from a particular
computer operating system, and/or application software running in the
computer, to a color printer which acts as a hardcopy output device.
These modern developments, however, have only exacerbated the
satisfactory-color problem for another group of users. Those are users who
haven't time or interest for making multiple manual selections, or haven't
sophistication for setting up exact desired on-screen color for matching
by a printout.
There is thus a need for a refined color-management technology which
somehow accommodates users of a wide variety of commitment, interest and
abilities. Such technology must at the same time overcome the inconsistent
color requirements, within a single composite document, of different types
of objects or "copy" such as photo images, business graphics, color text,
and black text.
As can now be seen, important aspects of the technology which is used in
the field of the invention are amenable to useful refinement.
SUMMARY OF THE DISCLOSURE
The present invention introduces such refinement. It allows for either
automatic or customized settings respecting color correction as well as
halftoning.
Before offering a relatively rigorous discussion of the present invention,
some informal orientation will be provided here. It is to be understood
that these first comments are not intended as a statement of the
invention.
The invention provides a method of automatic and manual control for
different color-correction and color-rendition options based on the type
of color object to be printed. A printer system includes an interactive
user interface with a choice between one-"button" automatic control of
color output, or alternatively multibutton manual control of color output.
Independent selections for halftoning techniques and for color correction
are separately made for different types of color objects such as text,
graphics and photo images.
Now with these preliminary observations in mind this discussion will
proceed to a perhaps more-formal summary. The present invention has more
than one main aspect or facet; these primary facets or aspects are
amenable to use independently of one another, although for optimum
enjoyment of all the benefits of the invention they are preferably
practiced in conjunction together.
In preferred embodiments of a first of these main facets, the present
invention is a printing system for use in printing objects of any of
plural different color-object types. This system includes a color printer.
The system also includes a printer control device that has a user
interface. This user interface in turn has an option for controlling two
separate print-quality characteristics based on the type of color object
to be printed by the color printer.
The foregoing may be a description or definition of the first primary
aspect of the present invention in its broadest or most general terms.
In preferred embodiments of a second of the main aspects of the invention,
the invention is a method of allowing the user to control the quality of
printing of a composite document having different types of objects. This
method includes the step of providing a user interface with a first option
for choosing automatic control of printer output based on the type of
color object to be printed.
The method also includes the step of allowing a second option for choosing
a manual control of printer output--but, here too, based on the type of
color object to be printed.
The foregoing may be a description or definition of the second primary
aspect of the present invention in its most general or broad terms.
Even with each of the two main facets of the invention as above-presented
in broad or general forms, however, as can now be seen each of these two
aspects of the invention makes important contribution to resolving the
previously outlined problems of the prior art.
In particular the first aspect of the invention simplifies and reduces the
color-management-setting decision-making demands on sophisticated human
operators by applying object type to control or trigger two separate
print-quality characteristics--a particularly powerful aid, in the modern
context of multiple objects and plural object types in each composite
document. The second facet of the invention makes the benefits of
object-type-dependent printer output available to both sophisticated,
demanding users (who may wish to carefully control each aspect of
printing, object type by object type) and those who wish to rely instead
on the system designers' color judgment--thus bridging the gap between the
needs of both groups.
Although the invention thus provides very significant advances relative to
the prior art, nevertheless for greatest enjoyment of the benefits of the
invention it is preferably practiced in conjunction with certain other
features or characteristics which enhance its benefits.
For example, as to the first main aspect of the invention, it is preferred
that the user interface option include control of the two separate
print-quality characteristics automatically. By "automatically" here we
mean based on default values, as will be set forth with greater
particularity shortly.
Further it is preferable that the interface include a dialog screen having
a control for invoking the two-characteristic, type-dependent-control
option described above. It is also preferred that this dialog-screen
control include a visual representation of a single control button, and
some means for invoking that option in responsive to physical interaction
with that visual representation of a button.
We also consider it preferable that the dialog screen enable manual
selection of a halftone technique, as well as manual selection of a color
correction, both based on the type of color object to be printed. Also
preferable to include in the user interface is a further option to enable
manual control of the lightness range of objects to be printed.
It is also preferable that the user interface display manual default
settings for the previously-mentioned two separate print-quality
characteristics, when a control is actuated to make manual selections. It
is also desirable to provide predetermined automatic default settings for
the two separate print-quality characteristics when a control is actuated
to invoke automatic selections.
To reduce operator confusion and seeming complexity of the system, in use,
we deem it preferable that these predetermined automatic default settings
be the same as the manual default settings. It is also preferable that the
user interface allow the creation of new default settings for the two
separate print-quality characteristics--which new default settings are
different from original or factory-preset default settings.
This last-mentioned feature relieves a user who wishes to use personally
preferred settings of the chore of entering them repetitively. An
additional control, however, is also desirable to allow the system to be
returned from such "new" default settings to original default settings--in
case a system changes hands or has multiple users, etc.
It is also particularly preferable that the system include automatic
control of two different printing characteristics, based on whether the
color objects to be printed are photograph-like images or graphics or
text.
All of the foregoing operational principles and advantages of the present
invention, as well as several others, will be more fully appreciated upon
consideration of the following detailed description, with reference to the
appended drawings, of which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a computer system employing a
now-preferred embodiment of the invention;
FIGS. 2 and 3 are a flow chart showing how the automatic and manual options
of FIG. 1 are used to produce a color printout of a composite document;
FIGS. 4 and 5 show a sequence of interactive computer screens available to
a user who proceeds through the flow chart of FIGS. 2 and 3;
FIG. 6 is a schematic block diagram--particularly emphasizing the flow of
user options or choices--of a system for producing printouts of color
photographs, and other photograph-like objects, in accordance with the
preferred embodiment of FIG. 1;
FIG. 7 is a halftoning flow chart for the same embodiment but particularly
emphasizing the selection processes or sequence within the equipment;
FIG. 8 is a color control flow chart for the same embodiment;
FIG. 9 is a functional block diagram showing the relationship of color
control and halftoning in processing and printing photographic images;
FIG. 10 is a schematic diagram showing the different color gamuts of
visible light, a computer screen, and a printer which are used in the
color control flow chart of FIG. 8; and
FIGS. 11 and 12 show a typical color inkjet printer for incorporating the
color printout features of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Generally speaking, the invention provides improved print quality for
composite documents which have different types of objects to be printed in
the same document and in many instances on the same page. In an exemplary
printer system as illustrated in the drawings, one or more different types
of color objects 41-43 (FIG. 2) are identified and flagged 54 (FIG. 3); a
preferred rendering option, such as halftoning, and/or color matching is
selected for each one of such different color-object types; and then the
document is printed in accordance with the rendering and color-control
options selected for each of such different color-object types.
The color inkjet system of the preferred embodiment includes a printer 56a,
56b (FIGS. 1 and 3) coupled through a printer driver 32 to applications
(or operating-system) software 31 running in a host computer 44. A set of
default halftoning techniques and default color-matching maps is
incorporated in the printer system for automatic invocation whenever
objects of respective particular color-object types are to be printed in
the absence of user selections.
The invention has features which provide either automatic or manual
implementation of various color-control and rendering options. For
example, in the color inkjet system shown an interactive user interface
allows a choice between one-"button" 62 automatic control 53A of color
output or multibutton control 63-99 of color output, with both automatic
and manual options providing independent control for color halftoning 90
and for color correction 81 based on the types of objects to be printed.
(As will of course be understood, any notation such as "63-99" is a
shorthand way of referring to only whatever reference numbers in the
stated interval are actually present, viz. here 63-68, 70-74, 80-87, and
90-99.) The preferred form allows separate print-control options for text
43/85, graphics 42/86 and photo (or photograph-like) images 41/87.
Different print-quality modes 65 in the printer invoke 11, 12 different
print-rendering options 21, 22 for a particular object to be printed. In
the exemplary embodiment, a printer control 65 automatically invokes an
error-diffusion halftoning technique 22 for photo images 41 whenever a
high-quality mode 66 is designated, and automatically invokes a dither
halftoning technique 21 for photo images 41 whenever a normal 67 or fast
68 print mode is designated.
It is important to note that the location of the color-management
functionality is somewhat flexible within the printer system. Such
functionality in the presently preferred version of the invention is
primarily in the printer driver 32, but it could be implemented in the
printer driver and/or printer 56 firmware--and/or even in the printer 56
hardware (e.g., custom integrated circuits, etc.).
The preferred embodiment of the invention is used in an inkjet printer of
the type shown in FIG. 11. In particular, inkjet printer 110 includes an
input tray 112 containing sheets of a printing medium 114, which pass
through a print zone and are fed past an exit 118 into an output tray 116.
As seen in FIGS. 11 and 12, a movable carriage 120 holds print cartridges
122, 124, 126 and 128--which in turn respectively hold yellow (Y), magenta
(M), cyan (C) and black (K) inks. The front of the carriage has a support
bumper 130, which rides along a guide 132; while the back of the carriage
has multiple bushings such as 134, which ride along a slide rod 136.
The position of the carriage as it travels back and forth across the medium
is determined from an encoder strip 138. This position information is used
to selectively fire the various ink nozzles on each print cartridge at the
appropriate times during each carriage scan.
The preferred embodiment makes use of and performs in the environment of
well-known commercially available color-matching specifications and
operating-system software whose use is very widespread. These are
respectively Pantone.RTM. Color and Microsoft's Windows.RTM. 3.1; the
following details accordingly, for definiteness, are couched in terms of
these familiar modules. The role of Pantone in this environment is, in
essence, as arbiter of what may be called "true" color; however, those
skilled in the field will understand that even this represents simply an
effort to provide a reliably expert evaluation of what is inherently
subjective.
The preferred embodiment further has been embodied in color printing
devices 56, 110 commercially available from the Hewlett Packard Company as
its DeskJet.RTM. model 1200C and PaintJet.RTM. model XL300. We will
sometimes in this document refer to these devices in abbreviated form as
the DJ 1200C and PJ XL300 respectively.
Readers skilled in the art, however, will appreciate that the present
invention is not limited to this environment. Rather, on the contrary, the
invention both in principle and in practice has much broader applicability
for use in any of a great variety of present and future
color-matching/operating-system/printer environments.
In Windows.RTM. 3.1, Microsoft developed the concept of a so-called "common
print dialog" 70 (FIG. 4). This "dialog" screen is called from different
points within the application or from Windows directly. When this dialog
function 70 has been used, some features of the color-printing-driver 32
"Setup Dialog" screen 60 have been addressed already: these features are
"Orientation" 71, "Media Size" (e.g., paper size) 73 and "Media Source"
(e.g., paper source) 72.
These features therefore need not be presented to the user again in the
print-driver 32 "Setup Dialog". With this in mind, the driver is best
configured to display only a modified version 60' of the Setup Dialog 60
when the driver 32 is called from the common print dialog 70.
As shown in FIG. 5, the user options presented in the driver's "Manual
Color Options" screen 80 are divided into two categories. The first
category 81-93 contains the settings labeled "Printed Color Control" 81
and "Halftoning" 90. These options can be selected on an object-by-object
41-43 basis; the object types in this case are text 85, graphics 86 and
photos--or photo-like images--87.
TABLE 1
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LIGHTNESS SLIDER settings and functions
.gamma. value for indicated slider setting
Color Control
lightest
lighter normal
darker
darkest
______________________________________
Accurate Match
0.5 0.7 1.0 1.2 1.4
Clear and Vibrant
0.5 0.7 1.0 1.2 1.4
No Adjustment
0.3 0.4 0.6 0.8 1.0
______________________________________
In other words, the Printed Color Control 81 can be set for text 85 to a
mode that is different from the mode or modes selected for graphics 86 and
for photographic images or the like 87. The Halftoning method 90 too can
be different for the three different types of objects 85-87.
The second category 96, 97 contains the "Lightness" slider 96 and the
"Lookup-Table Colors" (e.g., "Pantone Colors") mode control 97. In the
preferred embodiment these options can be set only on a job-by-job basis.
This means that the Lightness 96 and Lookup-Table mode 97 act upon the
entire job regardless of what types of objects are in each job (or on each
page of the job).
The driver adjusts the incoming red, green and blue (RGB) data by applying
a "gamma" (contrast function) correction to produce adjusted RGB data as
indicated in Table 1.
In configuring the preferred embodiment, the color transfer functions of
both the DJ 1200C and the PJ XL300 were characterized to create a lookup
(e.g., Pantone.RTM. Color) table to be incorporated into the driver. When
this mode is selected, the driver checks all incoming RGB values against
the key values provided by the lookup table. If there is an exact match,
then the driver maps (i.e., translates) the incoming RGB value into the
correct (as discerned by Pantone) RGB value to send to the printer--to
produce the closest approximation of the Pantone color selected.
TABLE 2
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PRINTED COLOR CONTROL/HALFTONING selections
for TEXT and GRAPHICS
Color-Control setting
Halftone
Clear and Accurate No
setting
Vivid Match Adjustment
key
______________________________________
Scatter
HMS color map
Accurate map
RGB .rarw.color
(#1) (#8) pass-through
"map"
HPL noise HPL noise HPL noise
.rarw.half-
toning
Cluster
HMS color map
Accurate map
RGB .rarw.color
(#2) (#9) pass-through
"map"
Current Current Current .rarw.half-
Cluster Cluster Cluster toning
dither dither dither
Pattern
HMS color map
Accurate map
RGB .rarw.color
(#3) (#10) pass-through
"map"
Current Current Current .rarw.half-
Bayer Bayer Bayer toning
dither dither dither
______________________________________
Only so-called "Plain Paper" has been Pantone certified for the DJ 1200C;
and "Special Paper" for the PJ XL300. In operating a system according to
the preferred embodiment, if a user attempts to select the "Look-up-Table
Colors" ("Pantone Colors") checkbox when the appropriate type 74/74' of
medium is not selected, a warning message appears.
"Defaults" button 98 (FIG. 5)--This control resets all the user options in
this dialog to the factory-default values for the prevailing mode. These
defaults 85'/86'/87'/85"/86"/87" are shown in the "Manual Color Options
Dialog" screen display 80 of FIG. 5.
"Calibrate Screen" button 99--This control brings up the so-called
"Calibration" utility. An operator will use this when it is desired to
recalibrate the monitor in order to assemble and store 14 new color maps
(tables) for an "Accurate Screen Match" mode.
TABLE 3
______________________________________
PRINTED COLOR CONTROL/HALFTONING selections
for PHOTOGRAPHIC images
Color-Control setting
Halftone
Clear and Accurate No
setting
Vivid Match Adjustment
key
______________________________________
Scatter
HMS color map
Accurate map
RGB .rarw.color
(#4, 5) (#8, 11) pass-through
"map"
HPL noise HPL noise HPL noise
.rarw.half-
with CV with CV with CV toning
or CMYK or CMYK or CMYK
Err. Diff. Err. Diff. Err. Diff.
Cluster
HMS color map
Accurate map
RGB .rarw.color
(#6) (#9) pass-through
"map"
Current Current Current .rarw.half-
Cluster Cluster Cluster toning
dither dither dither
Pattern
HMS color map
Accurate map
RGB .rarw.color
(#7) (#10) pass-through
"map"
Current Current Current .rarw.half-
Bayer Bayer Bayer toning
dither dither dither
______________________________________
Tables 2 and 3 show the types of color matching (or "mapping" 82-84) and
halftoning 21-27, 91, 92 (FIGS. 6 through 9) that are implemented in the
driver 32 for the various user-selectable options or settings in this
user-interface dialog 80. Following are definitions of the table entries.
"HMS type color map" 82 (FIG. 9)--This is a color-correction relationship
used to boost the vibrancy of the hue associated with an input or given
RGB value, as indicated by the designation "Vivid Color" in FIGS. 6
through 9.
"Accurate color map," 83--This is an alternative relationship created when
a user calibrates the monitor with screen calibration 99 (that is, using
the "Calibration" utility 14 mentioned above) in order to get printed
output 57 that matches what is on the user's screen 45. This map 83 is
then called up if the user actuates 81 (FIG. 6) the "Match Screen"
selection 83 of FIG. 5.
"No Adjustment" 84--With this setting the driver 32 does not do any
processing of incoming RGB data. This is the mode an operator may use to
control exactly the RGB values that are sent to the printer 56.
"HPL Noise with CV" 21 (FIGS. 6, 7 and 9)--This "Halftoning" 90 option
utilizes a 128.times.128-byte so-called "Noise dither" matrix 27, along
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