Ricoh InfoPrint Pro C900AFP InfoPrint Manager - Page 247

Color management, ICC profiles, Halftones, Tone transfer curves

Page 247 highlights

Halftones Grayscale printers apply halftones to print jobs to print them; halftones let the printer produce many shades of gray and high-quality images. Generally, the most important characteristic to consider for halftones in grayscale printing is line screen frequency, expressed in lines per inch (lpi). Each printer supports a set of line screen frequencies natively; when you specify the desired line screen frequency in a print job, the printer chooses the available line screen frequency that best matches it. Tone transfer curves Tone transfer curves are used in grayscale printing to adjust the amount of toner that is used at different levels of gray, thus adjusting the appearance of images. You can use the appearance value of a tone transfer curve in grayscale printing to indicate how much the tone transfer curve should adjust the color values. Some sample appearance values could be: v Dark v Highlight Midtone v Standard Color management Images, graphics, and photographs often appear different depending on the monitor or the printer you use. The colors printed by one printer might not match the colors printed on another printer, even if they came from the same source. If it is important that colors stay consistent from camera, scanner, or monitor to printer, you must use color management practices. It is virtually impossible to accurately reproduce the colors that you see on your monitor on a printed page. Because printers typically have smaller color gamuts than other devices, some of the colors must always be adjusted when images are transformed for printing. With color management, you can control the adjustments so they are less noticeable than they might be if you use the default settings of your image creation software, print server, and printer. Several factors play significant roles in color management, including ICC profiles, rendering intents, and paper characteristics. ICC profiles The International Color Consortium (ICC) is an organization that has established open standards for color management. These standards help products work together by identifying a device-independent color space and defining the elements of an ICC profile. The device-independent color space that the ICC defined is called the profile connection space (PCS). The PCS is a color space large enough to include all the color gamuts of different input, display, and output devices. An ICC profile contains methods that map the colors that a device can create or display to the values of the corresponding colors in the PCS. The ICC profile can be used to convert an image from a device-specific color space to the PCS, or from the PCS to a device-specific color space. Product manufacturers create ICC profiles that you can use with their devices. For example, if you take a photograph with a digital camera, you can associate the Chapter 25. Color and grayscale printing using AFP 229

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Halftones
Grayscale printers apply halftones to print jobs to print them; halftones let the
printer produce many shades of gray and high-quality images. Generally, the most
important characteristic to consider for halftones in grayscale printing is line screen
frequency, expressed in lines per inch (lpi). Each printer supports a set of line
screen frequencies natively; when you specify the desired line screen frequency in
a print job, the printer chooses the available line screen frequency that best
matches it.
Tone transfer curves
Tone transfer curves are used in grayscale printing to adjust the amount of toner
that is used at different levels of gray, thus adjusting the appearance of images.
You can use the appearance value of a tone transfer curve in grayscale printing to
indicate how much the tone transfer curve should adjust the color values. Some
sample appearance values could be:
v
Dark
v
Highlight Midtone
v
Standard
Color management
Images, graphics, and photographs often appear different depending on the
monitor or the printer you use. The colors printed by one printer might not match
the colors printed on another printer, even if they came from the same source. If it
is important that colors stay consistent from camera, scanner, or monitor to printer,
you must use
color management
practices.
It is virtually impossible to accurately reproduce the colors that you see on your
monitor on a printed page. Because printers typically have smaller color gamuts
than other devices, some of the colors must always be adjusted when images are
transformed for printing. With color management, you can control the adjustments
so they are less noticeable than they might be if you use the default settings of
your image creation software, print server, and printer.
Several factors play significant roles in color management, including ICC profiles,
rendering intents, and paper characteristics.
ICC profiles
The International Color Consortium (ICC) is an organization that has established
open standards for color management. These standards help products work
together by identifying a device-independent color space and defining the elements
of an ICC profile.
The device-independent color space that the ICC defined is called the profile
connection space (PCS). The PCS is a color space large enough to include all the
color gamuts of different input, display, and output devices. An ICC profile
contains methods that map the colors that a device can create or display to the
values of the corresponding colors in the PCS. The ICC profile can be used to
convert an image from a device-specific color space to the PCS, or from the PCS to
a device-specific color space.
Product manufacturers create ICC profiles that you can use with their devices. For
example, if you take a photograph with a digital camera, you can associate the
Chapter 25. Color and grayscale printing using AFP
229