indicatrix (In French indicatrice) model of the distribution of the reflected/ remitted light in the room. In the center of the indicatrix, under the gloss angle, is the strongly directional radiation share, and around it the weaker diffuse share.

indexed colors (In French couleurs indexées) see color indexing

INCQC, International Newspaper Color Quality Club (In French club of the research association of the WAN-IFRA newspaper industry) which grants club membership of newspaper printing houses for a period of 2 years on account of the color rendering quality of their printed products and the color management expertise of its personnel.

incidence angle (In French angle d’incidence) irradiation angle which must enclose 45° with the viewing/measuring angle during color matching and color measuring (freedom from gloss).

in-line measurement (In French mesurage en ligne) process or machineintegrated measurement, often as part of a closed loop control system. Example: QualiTronic ColorControl automatic color density control in KBA sheet-fed offset presses with a colorimetric camera as integrated measuring instrument.

in-gamut color (In French couleur affichable) see gamut mapping

image quality (In French qualité de l’image) criteria for image reproduction; subjective: motif, aesthetics; objective: color rendering, color appearance (CIECAM02), contrast, detail sharpness, noise.

image editing (In French traitement d’image) all changes carried out digitally to the image content; global color values: color cast removal (white alignment), use of device profiles, color tune correction, tone value ranges (highlights, medium tones, shadow tones); local color values: color changes; means of working: abstract (RGB, CMYK, CIELAB values) and intuitive (lightness/chromaticness/hue levels).

image data base (In French base de données d’images) archive often implemented as a content management system in which pixel and vector graphics files are saved with head words and administrative data (metadata) and if possible also embedded ICC profiles; loss-free medium-neutral formats are practical (e.g. TIFF RGB, EPS, PDF).

illuminant (In French illuminant) defined spectral radiation distribution (spectral characteristic) of a light source, i.e. their shares in the blue, green and red areas of the visible spectrum, with respect to the effect of optical brighteners but also to their shares in the area close to UV; important standard illuminants: A (lightbulb), D50 (neutral daylight, standard in the printing and media industries), D65 (medium daylight), TL84 (store light/three-band lamp).

illuminance, irradiance (In French éclairement) intensity with which a surface is (uniformly) illuminated; SI units are lx [lux] and lm/m² [lumen per square meter], that is, the quotient of luminous flux and illuminated surface; other units are “international lux” (1 ilx = 1.019 lx) and phot (1 ph = 10000 lx).

ICC-compliant (In French conforme ICC) property of software, utilities and drivers which can read, create or in a suitable manner apply ICC profiles. Regardless of this, these applications differ not least in terms of the consistency with which the ICC regulations are fulfilled, so that color management is not implemented largely correctly by all applications. This means therefore that conformity is also characterized by reliable operability and intelligent usability.

ICC profile (In French profil ICC) standardized data file which describes the color space or the color rendering properties of input, reproduction or output devices; see Tables I-2 “ICC profiles classification” on page 56

ICC Profile Format (In French format de profil ICC) color table format following the tag structure of TIFF, the version 4 of which was published as ISO 15076-1:2010 (still available for download free of charge at color.org). Besides the actual profile file format, the architecture of a color management system, rendering intents and the embedding of the profiles are also described.