BMP vs HDR
A detailed comparison of BMP Image and Radiance HDR Image — file size, quality, compatibility, and which format to choose for your workflow.
BMP Image
Raster & Vector ImagesBMP is an uncompressed raster image format native to Windows. Files are large but preserve exact pixel data with no compression artifacts. Rarely used on the web due to file size.
About BMP filesRadiance HDR Image
Raster & Vector ImagesHDR (Radiance) stores high dynamic range images for realistic lighting in 3D rendering.
About HDR filesStrengths Comparison
BMP Strengths
- Dead-simple format — trivially easy to read and write.
- Lossless and uncompressed — perfect bit-exact pixel storage.
- Universally supported in Windows applications since 1985.
- Supports 1, 4, 8, 16, 24, and 32-bit color depths.
HDR Strengths
- True floating-point dynamic range in 32 bits per pixel.
- Simple format — easy to parse and generate.
- Standard for environment maps and lighting probes in 3D.
- 30+ years of continuous use in architectural rendering.
Limitations
BMP Limitations
- Enormous file sizes — no meaningful compression in typical use.
- Not a web format — browsers support it but nobody serves BMPs over HTTP.
- No metadata support (no EXIF, no ICC profile in practice).
- Multiple header versions mean "a BMP" is ambiguous — parsers must handle several variants.
HDR Limitations
- No compression — files are larger than OpenEXR or AVIF for equivalent quality.
- Only one channel set (RGB) — no alpha, no multi-layer like EXR.
- Not a web format.
- Aging — OpenEXR is the modern professional choice.
Technical Specifications
| Specification | BMP | HDR |
|---|---|---|
| MIME type | image/bmp | image/vnd.radiance |
| Extensions | .bmp, .dib | .hdr, .pic |
| Compression | None (typical); RLE 4/8 bit (rare) | — |
| Color depths | 1, 4, 8, 16, 24, 32 bits per pixel | — |
| Byte order | Little-endian | — |
| Encoding | — | RGBE (shared 8-bit exponent) |
| Dynamic range | — | ~76 orders of magnitude |
| Creator | — | Greg Ward, Radiance renderer (1991) |
Typical File Sizes
BMP
- Small icon (32×32) 4 KB
- Screenshot (1920×1080) ~6 MB
- 4K image (3840×2160) ~25 MB
- Scanned A4 at 300 dpi ~25 MB
HDR
- 2K environment map 15-35 MB
- 4K environment map 60-130 MB
- 8K HDRI 250-500 MB
Ready to convert?
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Frequently Asked Questions
BMP (Bitmap) is a raster image format developed by Microsoft for Windows. It stores images with no compression by default, resulting in large file sizes but pixel-perfect quality. It has been part of Windows since version 1.0.
BMP (Bitmap) is a raster image formato developed by Microsoft para Windows. It stores images com no compressão by default, resulting in large tamanho do arquivos mas pixel-perfect quality. It has been part of Windows since version 1.0.
BMP files open in Windows Paint, Photos, macOS Preview, GIMP, Photoshop, and virtually any image viewer. All Windows applications support BMP natively.
BMP arquivos abrir in Windows Paint, Photos, macOS Preview, GIMP, Photoshop, e virtually any image viewer. All Windows aplicativos support BMP natively.
PNG is better than BMP in almost every scenario since it provides lossless compression (smaller files), transparency support, and wider cross-platform use. BMP is mainly relevant for legacy Windows applications.
PNG is melhor que BMP in almost every scenario since it fornece sem perdas compressão (smaller files), transparência support, e wider cross-platform use. BMP is mainly relevant para legacy Windows aplicativos.