Skip to content

Technical Reference

This section gathers the technical specifications of the project: Garmin IMG binary format, type codes, BD TOPO mappings, styles, tools and observability.

Format & Architecture

  • Garmin IMG Format

    Pedagogical architecture of the binary format: FAT, TRE / RGN / LBL / NET / NOD / DEM sub-files, delta encoding, subdivisions, GMP — enriched with Alpha 100 firmware discoveries.

    View

  • Garmin Types

    Hexadecimal codes for POI, roads and polygons in the Polish Map / Garmin IMG format.

    View

  • Format Limits

    Technical constraints of the Polish Map format and Garmin IMG format (points, levels, FAT size...).

    View

Data & Transformation

  • BD TOPO Mappings

    Transposition table of IGN BD TOPO layers to Garmin types, by source_layer.

    View

  • Zoom Levels and EndLevel

    Correspondence between EndLevel (.mp file), --levels (imgforge) and GPS zoom levels — 7-level header 24/23/22/21/20/18/16.

    View

  • Generalization Profiles

    Reference for the generalize-profiles.yaml catalog: YAML structure, Douglas-Peucker / Visvalingam-Whyatt algorithms, conditional dispatch, production BDTOPO profiles.

    View

  • Simplification Levels

    The 4 levels from least to most detailed: from maximum simplification (mpforge profiles + imgforge filters) to raw shapefile data without any filter — command triplets for each level.

    View

Tools & Configuration

  • --base-id Convention

    base-id ranges by coverage (departments, regions, quadrants, national) — avoids INSEE / DOM-COM collisions.

    View

  • Binary Versioning

    How imgforge and mpforge compute their version at compilation: reading --version, tag convention, release workflow.

    View

Visual Styles

  • TYP Styles

    Complete reference of TYP styles (POI, lines, polygons) used to customize the rendering of Garmin maps — generated from I2023100.typ.

    View

  • OpenTopo Styles

    Catalog of OpenTopo styles (POI, lines, polygons) — alternative rendering for OSM data.

    View

Observability

  • mpforge Logs

    Guide to reading mpforge log messages: verbosity levels, pipeline phases, common warnings, RUST_LOG filtering, JSON report.

    View

  • imgforge Logs

    Guide to reading imgforge log messages: verbosity levels, progress bar, console summary, common warnings, JSON report.

    View

Comments

Comments are managed by Comentario, self-hosted at comentario.allfabox.fr. Posting a comment may set a session cookie.

Fund a summit