What is a .BW file?
BW is a black-and-white image from Silicon Graphics systems.
- Did you know
- BW is the single-channel greyscale variant of the SGI image format.
- The SGI image format was invented by Paul Haeberli, and the .bw extension marks its single-channel black-and-white variant.
- Every SGI image starts with the magic number 474, and sibling extensions signal the channels: .rgb for colour, .rgba with alpha and .bw for plain greyscale.
- What Analyser reads
- Decode and preview extra still-image formats in pure JavaScript - Truevision TGA, QOI, Netpbm (PPM/PGM/PBM), PCX, farbfeld, WBMP, XBM/XPM, Sun Raster and SGI are fully rendered - and read header metadata from codec-heavy formats: Radiance HDR, DirectDraw Surface (DDS) game textures, OpenEXR, JPEG 2000, JPEG XR, EPS/PostScript, Windows WMF/EMF metafiles, Apple ICNS icons, CUR/ANI cursors, MNG and Lottie animations.
- Depth of analysis
- .BW is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .BW file
- Drag a .BW file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.