Color Balance Setting

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Color Balance Setting
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What Is Color Balance?

• Color Balance is a color correction option that
  provides a user with the ability to manually
  increase or decrease the amount of toner being
  applied for each color plane.
• Color Balance allows for each color plane to be
  modified individually. For example, a user could
  increase the amount of Cyan being used, decrease
  the amount of Magenta, and leave the Yellow and
  Black output alone.
• Caution Modifications made in Color Balance
  will change all output colors that use the
  particular color planes being adjusted. Thus
  while certain Color Balance changes might
  'correct' the color output for a particular
  image, those same changes could produce less
  desirable colors in another image.

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When Might Color BalanceBe Useful?

• Color Balance could be useful when a cartridge is
  printing either too light or too dark.
• Color Balance could be useful for applying a
  desired color shift to a particular image.
• If a customer believes that in general, the
  printers color output is a little too red, too
  blue, too yellow, etc., then Color Balance could
  be used to adjust the color output more to the
  customers preference.

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When Would Color BalanceNot Be Useful?

• Color Balance is not a solution for customers
  dissatisfied with the color output of only
  certain hues. For example, if a customer
  believes that in general the blues are too purple
  but likes everything else, then Color Balance
  will probably not help. Reductions made to
  Magenta to improve the blues would weaken the
  reds.
• Color Balance is not a solution for day-to-day,
  inter-page or intra-page color variation
  problems.
• Color Balance should not be used to solve
  problems such as logo matching. It is possible
  that Color Balance adjustments could be made to
  ensure the color output for a company logo is
  correct. However, this may cause undesirable
  color shifts in other colors lowering the overall
  color quality of the printer.

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How Do I Implement Color Balance?

• Color Balance is currently only available on the
  Operator Panel under the Color menu option.
  There is no driver support.
• Each color plane can be set to an integer value
  ranging from 5 to 5. Negative values
  correspond to decreases in color output while
  positive values correspond to increases in color
  output.
• The 0 setting is default for all color planes and
  indicates that no color corrections will be made.
• The RESET DEFAULT option under the Color
  Balance Menu will reset all values back to 0.

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Technical Details

• Color Balance modifications are applied
  regardless of Print Mode setting, Color
  Correction setting, or Toner Darkness setting.
• The modifications are implemented after internal
  color table corrections are applied to the
  incoming color data.
• Postscript only (PCL jobs not affected).
• Not connected with Toner Patch Sensing
  algorithms.
• This is only a software implementation i.e.
  laser settings are not adjusted.

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More Technical Details

• Toner level for a particular color is represented
  by an integer number ranging from 0 (no toner) to
  255 (maximum toner).
• Color Balance modifies a colors toner level
  number according to the formula
• output toner level (input toner
  level/255)gamma 255.
• The value of gamma implemented in the above
  equation is determined by the Color Balance
  setting (-5 to 5) selected by the user.
• The following slide illustrates the color
  modifications made to toner levels for a few
  choices of gamma.
• Observe from the following slide that darker
  colors (those near 255) are not affected much by
  Color Balance.

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Example Gamma Curves For Color Balance
255
Setting 5
Setting 0 (No Change Applied)
Setting -5
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Summary

• Color Balance is a flexible color adjustment tool
  that can potentially solve certain specific color
  output problems a customer may be experiencing.
• There are potentially confusing aspects of Color
  Balances implementation. Additionally, Color
  Balance can create substantial distortions to
  color output. To minimize the possibility of
  customer confusion and dissatisfaction with our
  products, RIP code with the Color Balance option
  enabled is to be distributed only to customers
  with a specific color output problem that Color
  Balance can potentially address. Additionally,
  someone with a good understanding of color should
  be present when demonstrating the Color Balance
  feature to a customer.
• The long-term implementation of Color Balance has
  not been decided. Its use on future products
  will be determined at a later date and will
  depend on customer feedback acceptance.