Image MIME Reference
PCO-B16
PCO B16 Image
image/vnd.pco.b16
VS
Silicon Graphics Image
image/x-rgb
SGI-RGB
A complete technical comparison of PCO B16 Image and Silicon Graphics Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | PCO-B16 | SGI-RGB |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
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
Silicon Graphics Image
image/x-rgb
Extension
.rgb.sgi.rgba.bw.int.inta
Container
SGI Image Header (512 bytes)
Compression
Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneScanline RLE
Color Depth
8-bit (Per Channel), 16-bit (Per Channel)
Developed by
Silicon Graphics, Inc. (Paul Haeberli)
Released
1988
Magic Bytes
01 DA
Browser Support Comparison
| Browser | PCO-B16 | SGI-RGB |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
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
SGI-RGB
SGI-RGB Strengths
- Supports 16-bit precision per channel and an embedded alpha channel, making it ideal for the demanding compositing workflows of 1990s cinema VFX
- The scanline-based RLE compression was exceptionally fast to decode on classic MIPS-based SGI workstations
- Features a straightforward 512-byte header, making it relatively easy to parse and write custom decoders in C or Python
Limitations
- Completely obsolete and unsupported in modern web environments
- Replaced entirely by TIFF, OpenEXR, and PNG in modern visual effects and 3D rendering pipelines
- Lacks support for modern color management via ICC profiles or advanced EXIF metadata
When to choose which format
PCO-B16
Use PCO-B16 when…
- Microscopy and Life Sciences
- High-Speed Camera Recording
- Machine Vision and Industrial Inspection
- Scientific Photometry
SGI-RGB
Use SGI-RGB when…
- Legacy 3D Animation and VFX Textures
- Silicon Graphics IRIX Workstation Archival
- 1990s Medical Imaging