So far in these articles accompanying the competition for the International Newspaper Color Quality Club 2002-2004, we have covered areas such as printing colors to meet the ISO 12647-3 Standard, monitor calibration, calibration of plates and computer-to-plate imagesetters, dot gain and gray balance. Here we build on these foundations to implement a color management system approach to color reproduction.

A color management system is usually synonymous with software that provides a batch processing capability for color separating images. In practice, the software needs to be highly sophisticated in handling color. Such a CMS is most beneficial when it acts as a translation service between a device that can record or display a relatively large color space (having a large color range), such as cameras, scanners and monitors, and a device that can record only a relatively small color space, such as printing presses and proofers. This is particularly the case with newspapers, where the printed color space or gamut is less than one-third of the size of photographic color film (see Fig. 1).

Fig. 1
DIFFERENT COLOR SPACES: generic digital camera, film, monitor and newspaper color spaces, and a proprietary monitor color space.
Photo courtesy of Ifra

The key point is these types of color management systems are dealing with a very restricted, but important, part of the production workflow. They are not dealing with image enhancement functions like sharpening, radical changes to the tone reproduction or the removal of dust, scratches and JPEG artifacts. They manipulate and compress color, mainly while trying to preserve the appearance of the original scene. They are a building block in color reproduction.



Fig. 2
Photoshop 6.0 CMS ‘Color Settings’ dialogue.

Benefits of using a CMS

As can be appreciated, a color management system is really a broad-based concept that needs to be a seamless workflow. This workflow extends from the major sources of images for newspapers, through the production processes and all the way through to the readers of newspapers on the Internet. Some of the major bodies that benefit from color management include: advertising bureaus; repro houses; ad departments; news picture agencies; photographers and photo editors; newspaper and magazine printing plants; and newspaper and magazine Web servers. For normal production, there are several powerful reasons to use a CMS:

• converts colors from one color space to another objectively; there is little or no operator subjectivity or variability;

• does not create colors that cannot be produced;

• allows predictable color throughout the workflow;

• allows a simpler and much faster handling of editorial images and ads,

• can produce a color-managed soft proof on the monitor (screen proofing is now more realistic in Photoshop 6).

There are two important corollaries:

• A CMS does not improve bad originals. Often image quality may need to be enhanced first. For a complete automation, a good combination would be a program for fast, high-quality automatic image processing followed by color separation using a CMS.

• A CMS can unknowingly compensate for some prepress and press maladjustment. Halftone dot sizes for a printed picture are determined by the CMS using two files — one that characterizes the color space of the digitized picture, the input profile, and the other the CMYK color space and print characteristics embodied in the output profile. An output profile is produced from a CMS automated analysis of a previously printed testform. If these testform prints come from production processes that are poorly controlled and not according to manufacturers’ specifications, a reduced tone range and inappropriate colors can be expected. Accordingly, with a CMS, it will include compensations for some of these production process shortcomings in calculating the halftone dot size needed for a correct image reproduction.

However, it should be emphasized that it is far better to optimize and standardize the production processes first before printing the CMS testform and making an output profile.

Implementing ISO 12647-3

With the development of a worldwide printing standard, ISO 12647-3, it would be a mistake not to implement it in the printing plants.

For the INCQC, we measure the color accuracy with which a newspaper color separates a set of color patches (the ANSI IT8.7/1 or 2, ISO 12641 Input Characterization Target) by comparing it to a set of target L*a*b* values. These target values are generated by a good gamut compression algorithm based on the ISO 12647-3 Standard for newsprint and news inks.

There are several natural consequences that follow from having a process that conforms to the ISO Standard:

• It is easier to obtain good marks in the “color accuracy” section of the INCQC. The target values for the INCQC are calculated using color data conforming to the ISO 12647-3 Standard.

• Printing with a standard CMS ICC output profile gives good results and can save money. Advertising customers demand not only a high level of color printing but also consistent color reproduction in all newspapers in which the ad appears.

Using this standard output file has led to some newspapers reducing the amount of claims for refunds or reprints of advertisements. Ifra’s Manfred Werfel, director of research and consulting, described examples where using a standard newspaper profile in a CMS has allowed newspapers to achieve monthly savings of $118,200 in one case and $12,000 in another. A third newspaper saved $1.8 million in two years through the adoption of a CMS and a standard profile. Newspapers must, and indeed want to, remain attractive for their national advertising market, which is almost entirely in color.

Another obvious benefit for using a CMS with a standard newspaper output profile is the good results for editorial images (but also advertising images). Images are printed without color casts, having good neutrals and skin tones and a full tone range from highlights to shadows. Ultimately for the INCQC 2002-2004, where the quality of the pictures in normal production has to be kept at a high level for a whole month, a CMS-based workflow would be a great advantage for most newspapers during the evaluations of general print quality. There would be a greater consistency of quality from prepress operator to prepress operator, from shift to shift and from day to day.

As part of daily production color management, pages with four-color images should include three-color gray patches alongside a monochrome black of the same lightness. These are a valuable visual aid for the pressman in addition to ensuring rapid and effective control of the inking adjustments.

Basic needs for a CMS

For a basic color management system, the following are needed:

• For the scanner: test charts, i.e. ISO 12641 color targets as photo prints or transparencies (also as 35 mm slides, if necessary) from different film manufacturers; manufacturers’ color reference data for each target; and profile-making software.

• For the monitor: a high-quality monitor; stable and optimized monitor surround lighting; tri-chromatic sensor or spectrophotometer with software; and profile-making software.

• For the press: a correct print of ISO 12647-3 target; a spectrophotometer; and profiling software.

• For the proofer: the same as the press requirements listed above.

Just as a well-printed output target from a well-controlled production process is needed for a good CMYK profile and consistent printing, monitor calibration is also of paramount importance for realistic and consistent color. Calibrated monitors are needed internally in many newspaper departments: for picture editors, advertising and production staff and as soft proof devices at the press. Often, it is not only a case of matching the color on multiple screens, in many departments, but also at multiple sites and sometimes in several countries. An objective method of achieving this is the only way.

Weak link

Currently, one of the major weak points in the whole CMS operation is that captured images are not colorimetrically defined at the source (the photographer), i.e. there is no objective reference for the color in the original. It is impossible to produce an ICC profile for every image taken by a news photographer, especially for images photographed on color negative film. However, as digital cameras are close to replacing film cameras for photojournalists, there are two developments that, in theory, should help the situation.

Firstly, cameras can be calibrated to deliver data in the context of a standard color space. The color space may be an RGB space, YCC or CIELAB. The LCD display on the camera or the photographer’s monitor image also has to conform to a standardized color space. Here again, the process is at the mercy of the photographer who is responsible for confirming the color accuracy of the file on his laptop before sending it to the agency or editor. Secondly, digital cameras can deliver each image with more details about the conditions under which it was captured (color space, gamma level, sharpness, brightness, shadow, highlight, saturation and overall color balance) — all within a JPEG file.

For the International Newspaper Color Quality Club, where the founding objective was and still is to raise the standard of quality of the daily newspaper, a color management system that operates over the whole origination and production process, continuously, is essentially the way newspapers should develop.