GeoTIFF Conversion from DXF/TIFF

Overview

The GeoTIFF map type in Configuration requires files in the WGS84 / EPSG coordinate system. Map exports from CAD tools are often delivered in a local projected system instead (e.g. SIRGAS 2000 UTM), and need to be converted first.

Two Python scripts are provided for this conversion:

Script	Input	Best for
dxf_to_wgs84_geotiff.py	DXF file	Pixel-accurate output — renders geometry directly from the DXF
tiff_to_wgs84.py	TIFF + DXF	Re-uses an existing rendered TIFF; trims page margins automatically

Downloads: dxf_to_wgs84_geotiff.py · tiff_to_wgs84.py

Requirements

pip install rasterio pyproj ezdxf numpy matplotlib

Note

matplotlib is only required by dxf_to_wgs84_geotiff.py.

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English

dxf_to_wgs84_geotiff.py

Reads the spatial extent from the DXF header, renders all line geometry (lines, polylines) with their original colours onto a georeferenced canvas, and reprojects the result to WGS84.

Usage

python dxf_to_wgs84_geotiff.py <input.dxf> [--out OUTPUT] [--epsg EPSG] [--res RESOLUTION]

Argument	Description	Default
input.dxf	Path to the source DXF file (required)	—
--out	Output GeoTIFF filename	output_wgs84.tiff
--epsg	EPSG code for the SIRGAS 2000 UTM zone	31982 (Zone 22S)
--res	Output resolution in metres per pixel	2.0

Examples

# Minimal
python dxf_to_wgs84_geotiff.py my_map.dxf

# Custom output and zone 23S
python dxf_to_wgs84_geotiff.py my_map.dxf --out mine_wgs84.tiff --epsg 31983

# Higher resolution (1 m/px)
python dxf_to_wgs84_geotiff.py my_map.dxf --res 1.0

tiff_to_wgs84.py

Takes an ungeoreferenced TIFF (typically a page-layout export from a CAD tool), automatically detects the map content area by trimming white page margins, maps the content to the bounding box read from the DXF header, and reprojects to WGS84.

Usage

python tiff_to_wgs84.py <input.tiff> <input.dxf> [--out OUTPUT] [--epsg EPSG]

Argument	Description	Default
input.tiff	Path to the source TIFF file (required)	—
input.dxf	Path to the DXF file for the bounding box (required)	—
--out	Output GeoTIFF filename	output_wgs84.tiff
--epsg	EPSG code for the SIRGAS 2000 UTM zone	31982 (Zone 22S)

Examples

# Minimal
python tiff_to_wgs84.py export.tiff map.dxf

# Custom output and zone 23S
python tiff_to_wgs84.py export.tiff map.dxf --out mine_wgs84.tiff --epsg 31983

EPSG codes for SIRGAS 2000 UTM zones

Code	Zone	Longitude range
31981	21S	57°W – 51°W
31982	22S	51°W – 45°W
31983	23S	45°W – 39°W
31984	24S	39°W – 33°W

Notes

• On Windows, run with python -X utf8 <script> to avoid console encoding issues.
• Both scripts output a LZW-compressed RGBA GeoTIFF that can be opened in QGIS, ArcGIS, Google Earth Pro, or any other GIS software, and uploaded directly as a GeoTIFF map layer in GroundControl.

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