Image MIME Reference
DPX
Digital Picture Exchange
image/dpx
VS
FAST Search & Transfer Image
image/vnd.fst
FST-Image
A complete technical comparison of Digital Picture Exchange and FAST Search & Transfer Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DPX | FST-Image |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
Digital Picture Exchange
image/dpx
Extension
.dpx
Container
DPX (SMPTE ST 268)
Compression
Uncompressed / RLE (Rarely used)
Algorithm
Uncompressed
Color Depth
8-bit, 10-bit, 12-bit, 16-bit, 32-bit (Float)
Developed by
SMPTE (Society of Motion Picture and Television Engineers)
Released
1994
Magic Bytes
53 44 50 58 (Big-endian) / 58 50 44 53 (Little-endian)
FAST Search & Transfer Image
image/vnd.fst
Extension
.fst
Container
Proprietary FAST Container
Compression
Proprietary
Algorithm
Unknown (Proprietary FAST encoding)
Color Depth
Unknown
Developed by
FAST Search & Transfer ASA (Arild Fuldseth)
Released
2000
Magic Bytes
Unknown (Proprietary)
Browser Support Comparison
| Browser | DPX | FST-Image |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DPX
DPX Strengths
- Industry standard for transferring uncompressed, high-fidelity film and VFX data
- Rich industry-specific metadata including timecode, keykode, and film stock information
- Supports logarithmic color spaces (LogC, Cineon) to preserve the massive dynamic range of film negatives
Limitations
- Massive file sizes (e.g., a single 4K 10-bit frame is ~50MB, resulting in ~1.2GB per second at 24fps)
- Zero native support in web browsers or consumer OS image viewers
- Requires heavy-duty, fast storage infrastructure (RAID/NVMe) to playback in real-time
FST-Image
FST-Image Strengths
- Historically served as an optimized, compressed format for FAST's early multimedia and live streaming engines over constrained late-1990s bandwidth
Limitations
- Completely obsolete and non-functional in modern software ecosystems
- Undocumented, closed-source binary structure with zero support in modern image processing libraries
- Shares its file extension with several other distinct file types (such as FL Studio state files or FAST Search dictionaries), leading to easy misidentification
When to choose which format
DPX
Use DPX when…
- Film Scanning
- Visual Effects (VFX)
- Digital Intermediate (DI)
- Color Grading
- Archival
FST-Image
Use FST-Image when…
- Historical FAST Enterprise Search Indexing
- Legacy Proprietary Multimedia Streaming (late 1990s)
- Internal Media Transmission