Image MIME Reference
DVB-SUB
DVB Subtitle
image/vnd.dvb.subtitle
VS
PCO B16 Image
image/vnd.pco.b16
PCO-B16
A complete technical comparison of DVB Subtitle and PCO B16 Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DVB-SUB | PCO-B16 |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
DVB Subtitle
image/vnd.dvb.subtitle
Extension
.sub.sup.ts
Container
MPEG-2 Transport Stream (MPEG-TS) PES Packets
Compression
Lossless (Run-Length Encoding)
Algorithm
RLE (Run-Length Encoding)
Color Depth
2-bit (Indexed), 4-bit (Indexed), 8-bit (Indexed CLUT)
Developed by
DVB Project (ETSI)
Released
1997
Magic Bytes
20
PCO B16 Image
image/vnd.pco.b16
Extension
.b16
Container
PCO B16 Binary Container
Compression
Uncompressed (Raw Sensor Data)
Algorithm
None
Color Depth
16-bit (Monochrome or Bayer Raw Color)
Developed by
PCO AG (Excelitas PCO GmbH)
Released
Early 2000s
Magic Bytes
50 43 4F 2D
Browser Support Comparison
| Browser | DVB-SUB | PCO-B16 |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DVB-SUB
DVB-SUB Strengths
- Guarantees 100% accurate visual representation (fonts, colors, layouts) exactly as intended by the broadcaster
- Effortlessly supports complex character sets (e.g., Arabic, Asian languages) without relying on the client device possessing the necessary fonts
- Supports region-specific dynamic positioning to avoid obscuring important on-screen graphics or burned-in lower thirds
Limitations
- Requires significantly more bandwidth than text-based subtitles
- Inaccessible to screen readers and cannot be indexed by search engines
- Requires OCR (Optical Character Recognition) to translate back into standard text-based web formats
- Zero native support in HTML5 video elements
PCO-B16
PCO-B16 Strengths
- Preserves exact, uncompressed 16-bit raw sensor data, which is critically important for accurate scientific measurements, fluorescence microscopy, and photometry
- The simple, linear struct header is highly predictable and easy to parse in custom Python, MATLAB, or C++ scripts for researchers building bespoke pipelines
Limitations
- Generates massive file sizes due to the complete lack of image compression [1.3.1]
- Completely unsupported by standard operating systems, web browsers, and consumer image editing suites
- Strictly tied to the hardware and software ecosystems of a single camera manufacturer
When to choose which format
DVB-SUB
Use DVB-SUB when…
- Digital Television Broadcasts (DVB-T, DVB-S, DVB-C)
- IPTV and OTT Streaming
- Hardware Set-top Boxes
PCO-B16
Use PCO-B16 when…
- Microscopy and Life Sciences
- High-Speed Camera Recording
- Machine Vision and Industrial Inspection
- Scientific Photometry