Overview
ISO 24585-1:2023 - "Graphic technology - Multispectral imaging measurement and colorimetric computation for graphic arts and industrial application - Part 1: Parameters and measurement methods" defines procedures and requirements for spatially resolved spectral measurement of reflecting, flat objects using multispectral imaging. It covers instrument calibration, illumination and specimen preparation, spectral and spatial sampling, storage of multispectral images, and the computation of colorimetric (tristimulus) values for graphic-arts workflows - including inline colour measurements in production printing. The standard excludes transmitting or self‑illuminating objects (e.g., displays), metallic/interference foils, and step-and-repeat spot scanning instruments.
Key Topics and Requirements
- Instrument calibration and adjustment: procedures to establish measurement traceability and reproducibility.
- Illumination requirements: specified wavelength ranges and measurement conditions (visible band focus; typical multispectral coverage can extend from ~380 nm to 730 nm).
- Spectral sampling: guidance on wavelength range, interval and bandwidth; notes that ISO 13655 prescribes 400–700 nm at 20 nm intervals as a reference.
- Spatial resolution and light-capturing: requirements for spatially resolved capture to enable pixel-wise colour evaluation.
- Multispectral image storage and data reporting: formats and metadata required to support reproducible colorimetric computation and comparison.
- Tristimulus computation and comparison: methods to compute and compare tristimulus images derived from multispectral data, including requirements for inter‑image and inter‑instrument agreement.
- Conformance and reporting: criteria for documenting compliance and reporting measurement results.
Applications and Users
Practical applications include:
- Print quality assurance and inline process monitoring in production printing (offset, flexography, gravure, screen, digital press).
- Color management and profiling for multi-ink and extended-gamut printing (including inks beyond CMYK).
- Material and surface appearance characterization where spatially varying colour matters (labels, packaging, patterned laminations).
Who uses it:
- Print manufacturers, quality engineers and production managers.
- Color scientists, imaging system designers, and multispectral camera manufacturers.
- Standards bodies and laboratories performing inter‑instrument comparisons.
Related Standards
- ISO 13655 - Spectral measurement and colorimetric computation for graphic arts images (reference for spectral sampling conventions).
- ISO 23603 - Assessing spectral quality of daylight simulators.
- ASTM E2022-16 - Method to compute weighting factors when using non‑standard spectral bands.
ISO 24585-1:2023 provides a standardized framework to ensure multispectral imaging delivers reliable, comparable colour data for graphic-arts and industrial workflows, supporting better color fidelity, pixel-wise quality control, and consistent reporting across systems.