BMP vs DNG — Differences, File Size & When to Use Each

BMP vs DNG

A detailed comparison of BMP Image and Digital Negative (RAW) — file size, quality, compatibility, and which format to choose for your workflow.

Convert DNG → BMP

BMP

BMP Image

Raster & Vector Images

BMP 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 files

DNG

Digital Negative (RAW)

Raster & Vector Images

DNG is Adobe's open RAW image format designed as a universal standard for camera raw data. It preserves full sensor data and extensive metadata, making it ideal for non-destructive photo editing.

About DNG files

Strengths 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.

DNG Strengths

Open, documented standard (ISO 12234-2) — future-proof for archival.
Based on TIFF — broad tool support beyond Adobe.
Can embed the original proprietary raw as a safety copy.
Smaller than most proprietary raws thanks to lossless compression.
Stores every Adobe Camera Raw adjustment inline, so edits travel with the file.

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.

DNG Limitations

Canon, Nikon, Sony, Fuji still refuse to adopt it.
Some manufacturer-specific features (Fuji film simulations, Nikon Picture Control) are lost in conversion.
Slower workflow — RAW from camera must go through DNG Converter first.
Mobile ProRAW files are heavy (25-75 MB per shot on iPhone).

Technical Specifications

Specification	BMP	DNG
MIME type	image/bmp	image/x-adobe-dng
Extensions	.bmp, .dib	—
Compression	None (typical); RLE 4/8 bit (rare)	Lossless JPEG, Lossy JPEG XL-like, Uncompressed
Color depths	1, 4, 8, 16, 24, 32 bits per pixel	—
Byte order	Little-endian	—
Extension	—	.dng
Container	—	TIFF/EP (ISO 12234-2)
Standard	—	Adobe DNG Specification 1.6

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

DNG

24 MP DNG (lossless compressed) 25-50 MB
Apple ProRAW 48 MP 50-75 MB
Medium-format DNG (50 MP) 60-100 MB

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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.