ISO/IEC TR 29158 (AIM DPM)
The AIM (Association for Automatic Identification and Mobility) Direct Part Mark (DPM) Quality Guideline improves upon the reliability of the ISO/IEC 15415 standard for 2-D barcodes and is intended to specifically handle the variety of marking techniques and part materials used in DPM applications.
AIM DPM primarily addresses the challenges of ISO/IEC 15415 through a different calculation of Global Threshold, improving contrast through additional illumination options and pre-processing to eliminate noise from the substrate. Like ISO 15415, AIM DPM analyzes the structure of the symbol and the reflectance of each of the module according to several parameters.
The final grade is based on eight individual parameters. The eight parameters are: minimum reflectance, decodability, cell contrast, cell modulation, fixed pattern damage, axial non-uniformity, grid non-uniformity and unused error correction. The final grade is the lowest grade of all of them. For example, if all of the metrics are given a grade of ‘A’ or ‘4’ but the decodability fails, then the grade is an ‘F.’