Department of Electrical Engineering and Automation

xDDiff (2024-2027)

The European Association of National Metrology Institutes (EURAMET) project xDDiff – “Multidimensional optical diffusion for the measurement of appearance”.

Consumers often rely on a product's visual branding and appearance when making purchasing decisions, highlighting the need for precise measurement of appearance during manufacturing. Currently, there is a gap in metrology for reliably measuring a product's visual traits, necessitating advancements in measurement techniques. Specifically, establishing accurate Bidirectional Reflectance Distribution Function (BRDF) measurements and creating scales for translucency and mattness that match perception are required. 
Furthermore, the interest of organizations such as the CIE and BIPM’s CCPR align closely with this initiative. 
Leveraging the EMPIR project BiRD, this project aims to enhance image-based goniospectrophotometers for reliable BRDF, BTDF, and BSSRDF measurement, and provide industry-relevant references and models. The project will define measurement scales for translucency and mattness linked to perception and offer protocols for 5% uncertainty in camera-based BRDF measurements. Collaboration with the EURAMET will drive industrial adoption and boost European competitiveness in advanced manufacturing.
The Metrology Research Institute (MRI) at Aalto University is actively contributing to Work Package 1 (WP1) of the xDDiff project. In WP1, Aalto is responsible for developing and characterizing camera-based goniospectrophotometers to achieve precise and traceable measurements of BRDF on complex anisotropic surfaces. The goal is to attain measurement standard uncertainties below 0.5% across all visible light wavelengths and relevant geometries. 
Ensuring comparability of results across all camera-based setups is critical; this will be validated by measuring two common samples across different systems. Traceability is maintained by linking BRDF scales from conventional to camera-based goniospectrophotometers, utilizing advancements from previous EMPIR projects, BiRD and BxDiff. 
 

Abstract floral design with red and orange petals, a green stem, and a yellow zigzag pattern.

More information can be found on the project website: 

Contact persons: Farshid Manoocheri (and Robin Aschan)

Robin Aschan

Farshid Manoocheri

  • Updated:
  • Published:
Share
URL copied!