Overview
EN ISO 16610-40:2015 (ISO 16610-40:2015) is a Geometrical Product Specification (GPS) standard that defines the basic concepts and terminology for morphological profile filters, including envelope filters. Part of the ISO 16610 filtration series, this standard introduces the mathematical and geometric foundations used in surface and profile filtration based on morphological operations such as dilation, erosion, opening and closing.
Key topics
- Morphological operations and terminology: Formal definitions for morphological operation, morphological filter, structuring element, dilation, erosion, opening and closing.
- Minkowski operations: Description of Minkowski addition and Minkowski subtraction as the set operations underpinning dilation and erosion.
- Filter properties: Key properties such as monotonicity and idempotence that distinguish morphological filters from basic morphological operations.
- Types of morphological filters: Introduction of discrete morphological filters, envelope filters (upper and lower envelopes generated by closing/opening), and higher-order morphological operations.
- Supporting concepts: Fill transform, sampling and reconstruction of profiles, and practical considerations for implementing morphological profile filters.
- Informative annexes: Relationship of morphological filters to the filtration matrix model and the GPS matrix model (see Annex B and C), plus a concept diagram to aid understanding.
Practical applications
EN ISO 16610-40:2015 is used where robust, geometry-based filtration of 2D profiles is required:
- Surface metrology and roughness analysis - defining and extracting envelopes or feature-scale separations.
- Calibration and verification of profilometers and surface-measurement instruments.
- Metrology and quality-control procedures in manufacturing (precision components, optics, automotive, aerospace).
- Software and algorithm developers implementing morphological profile filters in measurement and CAD/CAM toolchains.
- Research in surface texture, scale-space analysis and image/shape processing where set-based filtering is needed.
Who uses it: metrologists, QA engineers, instrumentation manufacturers, standards committees, metrology software developers and researchers in surface characterization.
Related standards
- ISO 16610-1:2015 - Filtration: Overview and basic concepts
- ISO 16610 series (Parts 20, 21, 22, 28, 30, 31, 32, 41, 49, etc.) - other profile and areal filter specifications
- ISO 17450-1 - GPS geometrical concepts (normative reference)
By standardizing the core geometry and terminology of morphological profile filtering, EN ISO 16610-40:2015 enables consistent specification, implementation and interpretation of morphological filters across metrology software, instruments and quality systems.
