Overview
IEC 62875:2015 - "Multimedia systems and equipment - Multimedia e‑publishing and e‑book technologies - Printing specification of texture map for auditory presentation of printed texts" - defines the printing quality and physical printing requirements for texture maps used to enable auditory presentation of printed texts. The standard specifies how a two‑dimensional data matrix (texture map) composed of square cells, alignment lines and tick marks should be printed on paper to ensure reliable scanning, decoding and interoperability with systems specified in IEC 62665.
Key topics and technical requirements
- Scope: Applies to texture maps printed on paper (also used on display devices), focusing on print quality to ensure interoperability with IEC 62665 texture maps.
- Minimum print resolution: Texture maps should be printed at ≥ 600 dpi on matte or low‑reflection paper to minimize specular reflection.
- Texture map sizes (number of cells / printed dimensions):
- XS: 40 × 40 cells - 6.8 × 6.8 mm
- S: 73 × 73 cells - 12.4 × 12.4 mm
- M: 106 × 106 cells - 17.9 × 17.9 mm
- L: 117 × 117 cells - 19.8 × 19.8 mm
- Definitions covered: texture map, data matrix, cell (square dot), alignment line (solid lines + tick marks), tick mark, quiet zone (non‑printing margin), and unit (11 × 11 cells).
- Printing quality measures: Overall quality is the average Q of eight measures (a–h). Each measure is scored and averaged to derive a grade A–F:
- a) Print contrast - computed as RC = (RL − RD) / RL where RL and RD are reflectance values of white and black cells; thresholds map to scores.
- b) Symmetry of cell pattern - compares widths of white/black reflectance patterns using a threshold RT and metric WS.
- c) Squareness, d) Size accuracy, e) Tick mark identification, f) Quiet zone sufficiency, g) Uselessness of error correction, h) Decodability.
- Sampling lines: Quality measures a–d use reflectance scans on 10 sampling lines (5 horizontal, 5 vertical). Sampling lines connect corresponding tick marks; for XS every tick mark is sampled, for S/M/L every other tick mark.
Applications and users
- Who uses IEC 62875:2015:
- Publishers and printers producing texture‑map‑enabled e‑publishing materials and e‑books.
- Manufacturers of scanning/imaging hardware and assistive audio‑output systems for printed texts.
- Accessibility technology developers and integrators working with auditory presentation workflows.
- Standards bodies and QA teams ensuring printed texture map interoperability.
- Practical uses:
- Ensures printed texture maps are reliably decoded for auditory playback of printed content.
- Provides print quality criteria for production, QA and procurement of printed accessible materials.
Related standards
- IEC 62665 - Texture map specification for auditory presentation (normative reference). Use IEC 62875 printing requirements together with IEC 62665 encoding and data matrix rules for full interoperability.
Keywords: IEC 62875:2015, texture map, auditory presentation, printing specification, multimedia e‑publishing, e‑book technologies, print contrast, sampling lines, quiet zone, alignment lines, tick marks, decodability.