ISO 16610-49:2015

Overview

ISO 16610-49:2015 - "Geometrical product specifications (GPS) - Filtration - Part 49: Morphological profile filters: Scale space techniques" - defines terminology and usage for morphological scale space techniques used in profile/surface filtration. The standard describes how to decompose profiles or surfaces into objects of different scale, ensuring the monotone persistence of features through scale space, and specifies recommended implementations for practical metrology.

Key topics and technical requirements

• Scope and terminology: Establishes basic terms for scale space filtration (scale, scale space, monotone property, sieve criterion).
• Size and anti-size distributions: Uses indexed families of openings (size distributions) to measure peak widths and closings (anti-size distributions) to measure valley widths.
• Sieve criterion: Mathematical nesting requirement that ordering of certain morphological mappings yields consistent results.
• Scale and monotone property: Scale is an indexing (nesting) parameter; once an object appears at a given scale it must persist down to zero scale.
• Alternating symmetrical filters: Defines four composite filter forms (M-, N-, R-, S-sieves) built from combinations of openings and closings to remove peaks and valleys below a chosen scale.
• Ladder / nested models: Describes a ladder structure of successive filtered representations and how to reconstruct the original signal and define transmission bandwidths between nested models.
• Recommendations:
  • Use circular disk and horizontal line structuring elements (details in ISO 16610-41).
  • Recommended M-sieve with a logarithmic (constant ratio) series of scale values; experience suggests a ratio around 2 between successive scales.
  • Start scale not less than the stylus tip radius when using contact stylus profilometry.

Practical applications

• Surface texture and profile analysis: Decomposing surface measurements to isolate features by scale (peaks, valleys) for texture characterization.
• Manufacturing quality control and metrology: Specifying and verifying surface functional requirements, roughness, and form at relevant scales.
• Data processing software and instrumentation: Implementing morphological scale space filters in profilometers, scanning systems, and metrology software to support GPS-compliant filtration.
• Research and standards development: Developing new measurement methods that require rigorous scale-based decomposition.

Who should use this standard

• Metrologists, quality engineers, and surface texture analysts
• Instrument manufacturers and software developers for profilometry and surface analysis
• Standards committees and laboratories implementing GPS-compliant filtration

Related standards

• ISO 16610-1:2015 (Overview and basic terminology)
• ISO 16610-40:2015 (Morphological profile filters: Basic concepts)
• ISO 16610-41 (Disk and horizontal line-segment filters)
• Other parts of the ISO 16610 series covering linear and areal filters

Keywords: ISO 16610-49, morphological profile filters, scale space, filtration, surface texture, profile analysis, size distribution, alternating symmetrical filters, metrology.