Image MIME Reference
Alias-PIX
Alias PIX Image
image/x-alias-pix
VS
Sony SR2 Raw Image
image/x-sony-sr2
Sony-SR2
A complete technical comparison of Alias PIX Image and Sony SR2 Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Alias-PIX | Sony-SR2 |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
Alias PIX Image
image/x-alias-pix
Extension
.pix.als.alias.img
Container
Alias PIX Header
Compression
Run-Length Encoding (RLE)
Algorithm
RLE
Color Depth
24-bit (RGB), 8-bit (Matte/Grayscale variant)
Developed by
Alias Research (Later Alias|Wavefront / Autodesk)
Released
Early 1990s
Magic Bytes
No explicit magic bytes (Relies on 10-byte integer header)
Sony SR2 Raw Image
image/x-sony-sr2
Extension
.sr2
Container
TIFF-based (Proprietary)
Compression
Uncompressed / Sony Proprietary Lossless
Algorithm
NoneSony Proprietary Lossless
Color Depth
12-bit (Per Channel)
Developed by
Sony Corporation
Released
2005
Magic Bytes
49 49 2A 00
Browser Support Comparison
| Browser | Alias-PIX | Sony-SR2 |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
Alias-PIX
Alias-PIX Strengths
- The highly simplified structure made it incredibly fast to encode and decode on early 1990s SGI hardware
- Lossless Run-Length Encoding (RLE) saved disk space without degrading the quality of final 3D renders
Limitations
- Completely obsolete, having been replaced by more robust formats like TIFF, TGA, and EXR in modern 3D pipelines
- The lack of a distinct magic byte signature makes reliable automated file detection almost impossible
- Does not support integrated alpha channels, instead requiring cumbersome, separate 'Matte' files to denote transparency
Sony-SR2
Sony-SR2 Strengths
- Retains raw, unprocessed sensor data from legacy cameras, allowing modern raw processors to extract vastly superior image quality than what was possible in 2005
- Utilizes a standard TIFF container structure, ensuring that community-maintained open-source decoding libraries (like LibRaw) can easily parse and maintain support for it indefinitely
Limitations
- Completely obsolete format that has not been utilized in a new camera release in over a decade
- MIME detection via magic bytes is unreliable due to TIFF header spoofing, requiring deeper EXIF inspection
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders
When to choose which format
Alias-PIX
Use Alias-PIX when…
- Legacy Alias PowerAnimator Textures
- 1990s SGI Workstation Render Outputs
- Historical 3D Graphics Archival
Sony-SR2
Use Sony-SR2 when…
- Legacy Sony Cyber-shot/Alpha Photography
- Non-destructive Image Post-Processing
- Raw Imaging Archival