Image MIME Reference
Sony-ARW
Sony Alpha Raw Image
image/x-sony-arw
VS
X Bitmap (Legacy MIME Alias)
image/x-xbm
XBM
A complete technical comparison of Sony Alpha Raw Image and X Bitmap (Legacy MIME Alias) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Sony-ARW | XBM |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
Sony Alpha Raw Image
image/x-sony-arw
Extension
.arw
Container
TIFF-based (Proprietary)
Compression
Uncompressed / Lossless Compressed / Lossy Compressed
Algorithm
NoneSony Proprietary LosslessSony Proprietary Lossy
Color Depth
12-bit (Per Channel), 14-bit (Per Channel)
Developed by
Sony Corporation
Released
2006
Magic Bytes
49 49 2A 00
X Bitmap (Legacy MIME Alias)
image/x-xbm
Extension
.xbm
Container
C Source Code Header (.h)
Compression
Uncompressed (Source Code)
Algorithm
None
Color Depth
1-bit (Monochrome)
Developed by
MIT / X Consortium (X Window System)
Released
1988
Magic Bytes
23 64 65 66 69 6e 65 (ASCII '#define')
Browser Support Comparison
| Browser | Sony-ARW | XBM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ |
✓
|
Sony-ARW
Sony-ARW Strengths
- Retains absolute maximum sensor data, enabling massive shadow recovery and highlight protection compared to compressed in-camera JPEGs
- Embeds high-quality JPEG previews and robust metadata, allowing photographers to match in-camera color science (like Creative Looks) perfectly during raw processing
- Utilizes the standard TIFF container structure, ensuring broad compatibility with open-source decoding libraries (like LibRaw)
Limitations
- Proprietary format means it requires constant updates to raw processing engines every time Sony releases a new camera model
- Sony's historically controversial lossy compression algorithm (often called 'star eater' due to spatial filtering artifacts) was a drawback for astrophotography in older ARW versions, though largely resolved in newer models with uncompressed/lossless options
- Cannot be directly embedded into web pages or used in standard HTML/CSS contexts
XBM
XBM Strengths
- Can be compiled directly into C or C++ source code without needing an external file loader or binary asset manager
- Human-readable structure allows developers to inspect, edit, or hand-craft tiny icons directly within a text editor
- Extremely predictable and lightweight for 1-bit hardware displays and embedded systems
Limitations
- Strictly limited to 1-bit monochrome (black and white) graphics with no gray or color support
- Text-based C syntax creates massive file bloat compared to binary 1-bit formats like PBM
- Completely deprecated in modern web browsers and desktop GUI frameworks
When to choose which format
Sony-ARW
Use Sony-ARW when…
- Professional Digital Photography
- Non-destructive Image Post-Processing
- High Dynamic Range (HDR) Imaging Archival
XBM
Use XBM when…
- X Window System (X11) Cursors and Icons
- Embedded C/C++ Firmware UI Assets
- Early 1990s Unix Web Graphics