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Federal Agencies Digitization Initiative Still Image Working Group — August 2010 temperature may also be necessary for older monitors to reach an appropriate brightness, as long as neutrals don’t appear too blue when compared to neutral hardcopy under the specified illumination. Monitor Calibration In order to meet and maintain the monitor settings summarized above, we recommend using LCD monitors designed for the graphic arts, photography, or multimedia markets. A photosensor-based color calibrator (colorimeter or spectrodensitometer) and appropriate software (either bundled with the monitor or a third party application) should be used to calibrate the monitor to the aims discussed above. This is to ensure desired color temperature, luminance level, neutral color balance, and linearity of the red, green, and blue representations on the monitor are achieved. If using an ICC color managed workflow (see section on color management), an ICC profile should be created after monitor calibration for correct rendering of images. The monitor should be checked regularly and recalibrated when necessary. Using a photosensor-based monitor calibrator, however, does not always ensure monitors are calibrated well. Ten years of practical experience has shown calibrators and calibration software may not work accurately or consistently. After calibration, it is important to assess the monitor visually, to make sure the monitor is adjusted appropriately. Assess overall contrast, brightness, and color neutrality of the gray desktop. Also, evaluate both color neutrality and detail rendering in white and black areas. This can be done using an image target of neutral patches ranging from black to white and saved in LAB color mode (since LAB does not require an ICC profile and can be viewed independently of the color managed process). In addition, it may be helpful to evaluate sample images or scans of targets — such as the NARA Monitor Adjustment Target (shown below) and/or a known image such as a scan of a Kodak grayscale adjusted to the aimpoints (such as the NARA aimpoints 8-8-8/105-105-105/247-247-247) described below. (wy) areca §§$When the monitor is adjusted and calibrated appropriately, the NARA Monitor Adjustment Target A : 7 - . Monitor Adjustment Target (shown at left) and/or an adjusted image of a Kodak gray scale will look reasonably accurate. Images with ICC color profiles will display accurately within color managed applications, and th shades tem selvte (RO. CO BM wo blak LOCA Be ae SRGB profiled images should display reasonably accurately outside color managed applications as well. The NARA Monitor Adjustment Target and 7 shamioe few whvbe, Ov grav ind tava black atvadien - i j iii ene § the cray scale aimpoints are based on an empirical evaluation of a large Fart viewing results, set maniter controls to ne ont at 1 1 : SS See eee) «number of monitors, on both Windows and Macintosh computers, and Mer! § represent the average of the group. Over the last fifteen of years calibrating and adjusting monitors in this manner, we have found the onscreen representation to be very good on a wide variety of monitors and computers. Quantifying Scanner/Digital Camera Performance Introduction A key element in our approach to developing guidelines is to describe and document a common foundation of quality metrics for investigating and evaluating digital objects created through digital imaging. The first table in this section (Part 1 — Taxonomy of Digital Imaging Performance) provides just that - a taxonomy of imaging performance. This hierarchical classification demonstrates the connections among related [existing] imaging characteristics, and provides context and a framework for the array of commonly used terms and the appropriate imaging standards available for the evaluation of digital image files. The additional five tables in this section (Part II — Evaluation and Quality Control of Digital Imaging) build upon the framework set forth in the first table and provide operational metrics and criteria for evaluating digital image characteristics for purposes of investigation or, when used with specific requirements, or for quality control purposes. Technical Guidelines for Digitizing Cultural Heritage Materials: Creation of Raster Image Master Files 7