Overview
ISO 12641-1:2025 - Graphic technology - Prepress digital data exchange - Part 1: Colour targets for input scanner calibration - specifies the layout and colorimetric aims for physical colour targets used to calibrate photographic product / input scanner combinations. The standard defines separate targets for positive colour transparency film and for colour photographic paper, and is intended for use in prepress workflows for printing and publishing. The target design is based on the CIE 1976 CIELAB colour space and supports both visual and numerical calibration methods.
Key technical topics and requirements
- Target design and layout
- Defined patch arrangements inspired by established film targets (e.g., Q‑60™ pattern with multiple hue angles, lightness levels and chroma samples).
- Vendor‑optional area for manufacturer‑specific patches.
- Transmission and reflection targets
- Separate clauses for transmission (film) and reflection (paper) targets covering physical characteristics and layout.
- Measurement geometries specified: transmission measurements (diffuse/normal or normal/diffuse) and reflection measurements (0°/45° or 45°/0°) consistent with ISO 13655.
- Patch size and spacing
- Requirements for minimum patch size to ensure accurate scanner sampling and reproducible measurement.
- Colour gamut mapping
- Use of a computed “common gamut” across dye sets; selection of chroma values (including product‑specific maximum chroma).
- Annex A provides computational reference material on gamut mapping.
- Neutral and dye scales / neutral scale mapping
- Inclusion of dye scale patches, dye pairs, neutral scales and product minimum/maximum density areas to characterise dye behaviour.
- Tolerances and target life
- Differing tolerances for uncalibrated vs calibrated targets to balance manufacturability and calibration precision.
- Guidance on usable target life for reliable calibration.
- Spectral measurement, colorimetric calculation and data handling
- Requirements for spectral measurement and colorimetric computation (per ISO 13655).
- Data reporting, file format requirements, keyword syntax and data identifiers for digital interchange.
- Informative guidance
- Annex B contains application notes to help implementers.
Practical applications and users
ISO 12641-1:2025 is used by:
- Scanner and scanner‑calibration tool manufacturers
- Film and photographic paper producers
- Prepress and color management engineers in print and publishing
- Quality assurance and reprographic labs
- Service bureaus and digital imaging workflows needing consistent cross‑device colour reproduction
Benefits include improved scanner-to-film/paper consistency, reproducible colour profiling, and robust prepress digital data exchange.
Related standards
- ISO 13655 - Spectral measurement and colorimetric computation for graphic arts images (referenced by ISO 12641-1)
- Historical alignment with ANSI IT8.7/1 and IT8.7/2 standards (digital data exchange legacy)
Keywords: ISO 12641-1:2025, colour targets, input scanner calibration, prepress, CIELAB, transmission targets, reflection targets, spectral measurement, colour gamut mapping, graphic technology.
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