Overview
ISO/IEC 18050:2006 - Information technology - Office equipment - Print quality attributes for machine readable Digital Postage Marks - defines standardized methods to measure and grade the print quality of two‑dimensional bar code symbols used as Digital Postage Marks (DPM). It provides two tailored measurement methodologies: one for multi‑row symbologies (e.g., PDF417) and one for two‑dimensional matrix symbologies (e.g., Data Matrix). The standard helps estimate read rates, identify causes of poor print quality, and guide corrective actions for reliable machine reading in postal applications.
Key topics and technical requirements
- Measurement methodology: Adapts the ISO/IEC 15415 approach to DPMs, specifying how to measure symbol attributes that affect readability.
- Two methodologies: Separate procedures for multi‑row and matrix symbologies to reflect differences in structure and scanning behavior.
- Grading scheme: Defines attribute grading levels (criticality grades 0–4) and a method to derive an overall symbol quality grade from multiple scans.
- Verification requirements: Requirements for verification equipment, optical geometry, light sources, and measuring apertures tailored to DPMs.
- Quiet zone and additional parameters: Guidance on margins and other parameters that influence decoding success.
- Printing system qualification: Test procedures and annexed guidance for qualifying printers and substrates for reliable DPM production.
- Diagnostic guidance: Informative annexes describe likely causes of low grades (contrast, modulation, defects, print growth, grid non‑uniformity) and recommended checks.
- Scope limitations: Applies to two‑dimensional symbologies with a defined reference decode algorithm; provides indicative read rates for limiting mean parameter values and may be partially applied to similar symbologies.
Practical applications and users
ISO/IEC 18050:2006 is intended for:
- Postal operators and carriers seeking reliable automated validation of postage marks and high read rates during sorting and processing.
- Mailers and print service providers who generate postage marks and need to ensure compliance and process control.
- Printing equipment manufacturers (inkjet, laser, thermal, direct thermal) who design and qualify systems for DPM production.
- Barcode verification and AIDC vendors who develop validation tools and decoding hardware/software.
- Quality engineers and test labs using standardized procedures to qualify substrates, inks, and production processes for consistent machine readability.
Related standards
- ISO/IEC 15415 (print quality measurement methodology for two‑dimensional symbols) - referenced and adapted for DPMs.
- UPU S‑28 (postal symbology recommendations) - commonly related for postal implementations.
Keywords: ISO/IEC 18050:2006, Digital Postage Marks, print quality, two‑dimensional bar code, PDF417, Data Matrix, barcode grading, postal automation, verification.