WebP — Google Web Image Format
Open BetaWebP is Google's open raster format built on the VP8 video codec (lossy) and its VP8L extension (lossless). On osm2cdr.ru the map is rendered to PNG and then transcoded to WebP via Pillow. In lossy mode the file is 25–35% lighter than JPEG; in lossless mode 26% lighter than PNG. WebP supports transparency and works in every mainstream browser. It is a finished map image, not editable layers — a handy lightweight format for previews and thumbnails, but not a replacement for GeoTIFF in full-size cartographic export.
Keskeiset ominaisuudet
Tietoa WebP-muodosta
WebP is Google's raster format, grown out of the VP8 video codec. It works in two modes: lossy, when weight matters, and lossless, when pixel accuracy matters. Transparency is supported by both modes, and WebP is displayed by every current browser.
For maps this is a screen format: a preview in a catalog, a picture in an article, an asset in a mobile app. Where PNG weighs more than it should and JPEG blurs thin road lines and labels, WebP gives a reasonable compromise between weight and readability.
The map is rendered to PNG and then re-encoded into WebP: lossy mode and quality 80 by default, or lossless mode with exact pixel reproduction if you prefer. This is a finished image: layers are not editable and there are no coordinates inside. For a print house take TIFF or PDF, for a GIS — GeoTIFF.
Mikä ohjelma avaa WebP-tiedostot
Seuraavat ohjelmat ja sovellukset voivat avata ja muokata OSM2CDR:stä vietyjä WebP — Google Web Image Format (.webp) -tiedostoja sekä työskennellä niiden parissa:
Format specifications
- Open standard
- 2D only
- Lossy compression
- No attributes
- Output: 1 file
- A single WebP transcoded from PNG via Pillow; lossy VP8 by default (~25-35% lighter than JPEG) with an optional lossless VP8L mode, alpha supported.
Ketkä käyttävät WebP-karttoja
Näin viet kartan muotoon WebP
Kuinka avata viennin jälkeen
- A browser — just open the file: Chrome, Firefox, Edge and Safari 14 and newer display WebP without plugins.
- A web page — <picture><source srcset="map.webp" type="image/webp"><img src="map.png" alt="map"></picture>: older clients will get the fallback PNG.
- GIMP, Affinity Photo, Photoshop 2022 and newer — they open and save WebP; handy for cropping the picture or adding a caption.
- ImageMagick or cwebp — re-encode to your own requirements: magick map.webp -quality 70 out.webp, or cwebp -lossless for exact pixel reproduction.
- Not for print — this is an RGB picture for the screen; for a print house take TIFF, CMYK TIFF or PDF.
Suositut WebP-kartat
Hanki WebP — Google Web Image Format -karttavientejä
Lataa ammattilaistason WebP-karttoja OpenStreetMapista. Luodaan välittömästi mistä tahansa alueesta.