isowall

Topographic isoline wallpapers generated from real-world elevation data.

Matterhorn — isowall.py matterhorn

Elevation comes from AWS Terrain Tiles (free, no API key). Contours are extracted with marching squares and rendered as antialiased vector lines colored by elevation.

Dolomites — -p blueprint	Big Sur — -p abyss (with bathymetry)

Setup

python3 -m venv .venv
.venv/bin/pip install -r requirements.txt

Usage

# a preset location
.venv/bin/python isowall.py matterhorn

# any place name (geocoded via OpenStreetMap — check the printed match)
.venv/bin/python isowall.py "lake como" --palette blueprint

# exact coordinates
.venv/bin/python isowall.py 46.55,7.98 --zoom 11 --palette ember

# see what's available
.venv/bin/python isowall.py --list-presets
.venv/bin/python isowall.py --list-palettes

Output defaults to a 4K PNG (3840x2160) in the current directory.

Web preview

.venv/bin/python server.py          # then open http://127.0.0.1:8000

An interactive preview UI: the server fetches elevation data and returns contour polylines, the browser renders them as SVG (fills the window like a real wallpaper). Palette changes are instant (recoloring happens client-side); sliders for zoom / levels / smooth / detail / aspect refetch automatically. The Map button opens an OpenStreetMap picker (Leaflet) — click to pick a location; the map zoom becomes the wallpaper zoom. Download PNG renders a full-resolution file via the same code path as the CLI (4500x3000 for 3:2, otherwise 3840px on the long edge). Press H to hide the panel.

Options

Flag	Default	Meaning
-p, --palette	midnight	color palette
-s, --size	3840x2160	output resolution WxH
-z, --zoom	11	map zoom 8–14, higher = closer in
-n, --levels	24	approximate number of contour levels
-i, --interval	auto	contour interval in meters (overrides --levels)
--smooth	1.6	gaussian smoothing of the terrain (0 = off)
--detail	1100	elevation grid width in samples (more = crisper detail, slower)
--line-scale	1.0	line width multiplier
-o, --output	auto	output path

Palettes

Dark: midnight, ember, forest, blueprint, mono, synthwave, oxide, aurora, magma, nebula, abyss, crimson, sakura. Pure black (#000000): matrix, onyx, noir, laser. Light: sand, paper, arctic. Each is a background color plus a low→high elevation gradient for the lines. Every 5th contour is drawn heavier (index contours), like a real topo map.

Add your own in the PALETTES dict at the top of isowall.py.

Structure

isowall.py       CLI renderer — tiles, contours, drawing (self-contained)
server.py        web preview backend
static/          web preview frontend (vanilla JS + SVG)
batch.py         render every preset × palette into wallpapers/
examples/        images used in this README

Notes

• Downloaded tiles are cached in .cache/tiles/, so re-rendering the same area with a different palette is fast.
• Coastal areas include bathymetry (underwater contours) — often looks great.
• If a location renders flat (open ocean, plains), try a different zoom.