ISO 16610-45:2025

Overview

ISO 16610-45:2025 - "Geometrical product specifications (GPS) - Filtration - Part 45: Morphological profile filters: Segmentation" defines terminology and core concepts for profile morphological segmentation used in surface texture and profile analysis. The standard specifies three segmentation approaches - watershed segmentation, the Wolf pruning method, and the crossing‑the‑line method - and assumes a continuous surface model. It is part of the ISO 16610 series on filtration and integrates with the GPS matrix model and other GPS standards.

Key topics and technical requirements

• Terminology and definitions: Precise definitions for topographic features (peaks, pits, hills, dales), profile events, and height measures (peak height, pit depth, hill local height, dale local depth).
• Segmentation types:
  • Watershed segmentation: Spatial decomposition of a profile into mutually exclusive portions (hills and dales).
  • Crossing‑the‑line segmentation: Segmentation based on profile crossings of a reference line combined with an aggregation algorithm to identify significant segments.
• Pruning methods:
  • Wolf pruning: A method to simplify change trees by removing minor connections between peaks and pits.
  • Change trees: Hill change trees and dale change trees describe peak–pit relationships and are used for pruning and simplification.
• Segmentation function and properties: The document formalizes a segmentation function that partitions events into significant and insignificant sets and specifies three segmentation properties (first, second, third) that govern consistent partitioning behavior.
• Height discrimination: Use of a height threshold (nesting index) to distinguish significant profile features during segmentation.
• Informative annexes: Additional guidance covering crossing‑the‑line implementation for element determination, hyperreal number considerations, and relationships to the filtration and GPS matrix models.

Practical applications and users

ISO 16610-45:2025 is intended for professionals and organizations involved in surface metrology and dimensional verification, including:

• Metrology engineers and calibration laboratories performing profile filtering and feature extraction.
• Quality engineers and inspection teams using profile segmentation to characterize surface texture, roughness, and functional features.
• Software developers of surface analysis and filtration tools implementing standardized segmentation and pruning algorithms.
• Designers and process engineers who rely on standardized surface descriptors for tribology, contact mechanics, sealing surfaces, and wear studies.

Adopting this standard improves consistency in profile decomposition, supports repeatable feature selection (using watershed, Wolf pruning, or crossing‑the‑line), and facilitates interoperability between instruments and analysis software.

Related standards

• ISO 16610-1 - Filtration: overview and basic concepts (normative reference).
• ISO 16610 series - Other filtration parts for morphological and linear filters.
• ISO 21920-2 - (Being superseded in part by this document) profile segmentation definitions alignment.
• ISO 14638, ISO 8015, ISO 14253-1 - GPS matrix model, fundamental GPS rules, and default decision rules referenced for application context.

Keywords: ISO 16610-45:2025, morphological profile filters, segmentation, watershed segmentation, Wolf pruning, crossing‑the‑line, profile segmentation, GPS filtration, hill change tree, height discrimination.