Konica Minolta micropress release 6 Manuel D’Utilisation
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These are linearization curves that ensure a 1:1
response between gray values requested in a job and
halftone values printed. Used to correct halftone
printers such as BiLevel, QuadLevel, and Mono-
chrome. The graph shows an example of a typical
response seen from a non-linearized imagesetter.
The curved line is the imagesetter’s response. The
The curved line is the imagesetter’s response. The
straight line is the desired 1:1 response. If a 50% tint
is sent to the imagesetter, a 30% tint is produced on
paper. To solve this problem, a linearization curve is
loaded into the RIP that defines the screen percent-
age to create based on the screen percentage
requested. In this example, the RIP would create a
higher screen percentage (60-70%) which, when
printed, produces a 50% screen on paper. Note:
Con-
tinuous tone devices (Contone, Gray) are linearized using Gammatic. Since “Tone Curves” require a
calibration curve to enable their use, “EnableToneCurves” is provided for Contone and Gray printers.
calibration curve to enable their use, “EnableToneCurves” is provided for Contone and Gray printers.
Tone Curves
Tone Curves are “adjustment curves” that modify the output of a printer currently using a cal-
ibration set. Used with both halftone and contone printers. For example, if a monochrome
printer using the “Linear Monochrome” calibration set produces dark output, apply the Tone
Curve “Light+10%” to lighten output by 10%. Where it may seem effectively the same as
modifying the calibration set, the power of Tone Curves is five-fold:
1 Available to all printer types.
2 Curve effect is the same, regardless of printer type.
3 Standard calibration sets (linearization curves) remain unaffected, providing a consis-
2 Curve effect is the same, regardless of printer type.
3 Standard calibration sets (linearization curves) remain unaffected, providing a consis-
tent baseline from which to work.
4 Since the printer is already linearized using the calibration set, Tone Curve values are
absolute, meaning a 5% increase in tone curve value will create a 5% decrease on
paper.
paper.
5 Can be used with the ICC Profile Processor to provide color adjustment capability and
color matching.
Using Tone Curves with Contone or Gray Printers: Contone and Gray printers are linear-
ized by Gammatic and do not require a calibration set. However, since Tone Curves are only
effective when a calibration set is loaded, a special calibration set called "EnableTone-
Curves" is loaded to enable Tone Curve use with these printers.
When to use Tone Curves: A Tone Curve modifies all jobs sent through the RIP. For half-
When to use Tone Curves: A Tone Curve modifies all jobs sent through the RIP. For half-
tone printers, this is the only method available for adjusting jobs. Contone or gray devices
can use both Tone Curves and PSM ColorCurves. ColorCurves are applied to individual Pos-
tRipped jobs so they don't affect other jobs or jobs being sent through the system (see the
PrintStation Manager Reference Manual). If you consistently use a particular ColorCurve for
adjustment, consider creating its Tone Curve equivalent and load it into the RIP to be auto-
matically applied.