All About Page-Level Color Detection

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Print job color detection refers to a process where a different print job cost is charged based on the use color. Most organizations charge/account more for color jobs because of:

  • Lease agreements - most leased devices have different “click costs” for color print jobs.
  • Color jobs use more expensive toner.
  • Color enabled devices are more expensive to purchase than a plain black & white printer.

PaperCut allows administrators to set a different cost on color vs grayscale (b&w) jobs and will apply these costs based on one of two different methods:

Standard Color Detection:

The color or grayscale charge is applied at the document level. It’s based on the user’s selection/use of the “grayscale” or “black and white only” option in the print preferences panel. If the user has selected Grayscale, the job will be charged at the discounted rate for black and white, otherwise the document is assumed to be color. Standard Color Detection is also known as Document Level Color Detection.

Page Level Color Detection:

Page-level color detection is a more advanced mode and it works by applying the different grayscale and color costs on a page by page basis. If the page contains any use of color, the color rate is applied for this page, otherwise the black and white rate is applied.

PaperCut accomplishes page level color detection by carefully analyzing each individual pixel on the printed page. It looks for use of color in all areas of a page such as:

  • images (in all formats, bit depths and compression forms)
  • text (including text using embedded True Type fonts)
  • vectors
  • and other graphics.

This analysis is done while the document is spooling to the print server before the print job is passed to the printer. This allows accurate costs to be calculated prior to print allowing appropriate actions to be taken as defined by the administrator.

Page-level color detection is usually also run in conjunction with hardware page count validation. The validation works by querying the printer’s hardware (via SNMP) after the job, to ensure the analysis done on the software layer on the server prior to printing is the same as observed by the hardware.

Q What printers support page-level color detection?

PaperCut supports page-level color detection for any printer that provides a Postscript, PCL, HP/GL or XPS driver. These terms refer to the print language (PDL) used by the printer/driver. The task of analyzing the stream of data sent to the printer looking for use of color is very complex and for this reason PaperCut only supports well documented printer languages. PostScript and PCL are standard languages which are publicly documented. The notable exception are GDI based printers.

GDI drivers use non-documented and proprietary languages, which are often evolving and in many cases it’s not viable to support page-level analysis for these drivers. PaperCut supports page-level color detection on the EMF spool file format so page-level detection is possible on some GDI drivers that spool the jobs in EMF format - results may vary so testing is always required. At a minimum, document-level color detection is supported in most GDI devices, and some GDI printers can support hardware-level validation.

Q Will page-level color detection slow printing?

Page-level color detection does add overhead to job analysis. It’s extra work to search through a document looking at every pixel for color than it is just looking for page ends/starts. However in the real world we find that the slowdown in analysis is minimal and not noted by end-users. The reason for this is that as soon as color is found on a page, the color analysis is turned off for the remainder of the page. In real-world documents, the increase in analysis time in around 10% to 20%. For example the analysis time of the PaperCut PDF manual (508 pages) in PCL6

Standard Detection315 ms
Page-Level Color Detection364 ms
Difference< 1ms per page

Q Does PaperCut support color coverage or 3-tired billing (e.g. enhanced/limited or color coverage)?

This topic is addressed in detail in Tiered Billing and Color Coverage.

Q Page-level color detection sounds good. Why would I NOT use it?

If your printer supports page-level color detection we recommend enabling it as it provides the most fair and accurate policy for charging print usage. There are however a few reasons why sites often choose not to enable it:

  1. If some printers can’t support page-level color detection, it may make sense to leave it off all printers to ensure that there is a standard and consistent charging policy across all devices in the organization.
  2. Page-level color detection can make it harder for a user to understand/predict a job cost.

If page-level color detection forms an important part of your print management strategy or print charging policy, please also take the time to read:


Categories: Tips & Tricks, Printers


Keywords: colour detection, printer configuration, charging, color page quotas, mono, monochrome, difference between standard detection and page level detection

Image: cc-by-ca by Siri Hardeland

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Article last modified on October 07, 2014, at 01:55 AM
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