Gigapixel wallpapers

driftwm’s canvas is infinite: windows float on an unbounded plane that you pan across and zoom out from. That leaves room for a background far larger than one screen — a gigapixel image can act as the canvas itself, something you pan over and zoom out to take in, rather than a fixed screen-sized wallpaper.

Why a tiled pyramidal TIFF

An ordinary PNG/JPG background is uploaded to the GPU as a single texture, which maxes out around 8K–16K pixels per side. Anything larger won’t fit — and that doesn’t take a literal gigapixel; a whole-world map or a large panorama is already over the line.

Instead it needs to be tiled (cut into small squares) and pyramidal (stored at several progressively smaller copies). driftwm loads only the tiles in view, and as you zoom out it switches to a smaller copy — so it never has to hold the whole image at full resolution. A tiled pyramidal TIFF packs all of that into one file.

Converting an image

The simplest route is libvips:

vips tiffsave input.jpg output.tif --tile --pyramid --bigtiff --compression=deflate

Then point your config at the result:

[background]
type = "tile"
path = "~/Pictures/output.tif"

--compression=deflate is lossless — preferable for a wallpaper you’ll zoom right into. --compression=jpeg is smaller but lossy.

Alternative: GDAL

If your source is already a GeoTIFF or you work with GIS tools, GDAL produces an equivalent tiled pyramid (a Cloud-Optimized GeoTIFF is a tiled pyramidal TIFF):

gdal_translate -of GTiff -co TILED=YES -co COMPRESS=DEFLATE input.tif output.tif
gdaladdo -r average output.tif 2 4 8 16 32

Where to find images

You just need a real downloadable file — a large JPEG, PNG, or TIFF past ~16K on a side. Skip zoom viewers that only stream tiles: Google Arts & Culture, the Rijksmuseum Night Watch viewer, and most of GigaPan don’t hand you the whole image. Beyond that it’s down to taste — the canvas tiles infinitely, but on something this large the repeat is far off-screen, so a non-seamless edge rarely matters.

Some sources:

• World & satellite maps — NASA’s Blue Marble is a public-domain whole-Earth image up to 43200 × 21600 px (TIFF/JPG). Maps suit the canvas nicely — panning around one feels like exploring.
• Wikimedia Commons — Large images and Gigapixel images: a big pool of maps, panoramas, and scans in the 16K–40K range, each with its license on its own page (many public domain or CC). If a download only gives you a thumbnail, see downloading very large files. Skip the Google Art Project subcategory — tile sets, not single files.
• Astronomy — ESA/Hubble’s Andromeda mosaic is 42208 × 9870 px under CC BY 4.0 (credit “ESA/Hubble”); NASA imagery is public domain. Many sky panoramas are only published small or viewer-only, so downloadable giant ones are fewer.

Then run your pick through the conversion step above.