Bitmap Image File (BMP/DIB)
Legacy Windows bitmap format still encountered in scanners, game assets, and older pipelines. Simple header + raw pixels — useful for understanding uncompressed raster layout.
What It Defines
Uncompressed or RLE-compressed raster format: `BM` magic, BITMAPFILEHEADER, DIB header (BITMAPINFOHEADER variant), optional color palette, then raw pixel data. Little-endian, bottom-up row order in classic BMP. MIME type: `image/bmp`.
Canonical (Normative)
Related References
Publishes web platform specs including CSS, accessibility, security policies, Service Workers, Web App Manifest, and many browser APIs. Also maintains some versioned HTML/DOM specs.
Related Specs
PNG is the default lossless image format on the web — screenshots, UI assets, icons with transparency, and OCR-friendly graphics. Chunk structure matters for metadata stripping and security review.
TIFF is the archival/print industry standard — scanned documents, GIS, medical imaging, and DNG raw photos. IFD tag model is a classic variable-header design.
Every upload, download, attachment, and asset pipeline crosses these layers. Misunderstanding header vs envelope causes MIME spoofing bugs, parser differentials, and broken file validation. Start here before diving into individual format specs.