Image MIME Reference
FastBid
FastBid Sheet
image/vnd.fastbidsheet
VS
Portable Anymap
image/x-portable-anymap
PNM
A complete technical comparison of FastBid Sheet and Portable Anymap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | FastBid | PNM |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
FastBid Sheet
image/vnd.fastbidsheet
Extension
.fbs
Container
Proprietary FastBid Container
Compression
Proprietary
Algorithm
Unknown
Color Depth
Unknown
Developed by
FastBid, Inc. (Scott Becker)
Released
Late 1990s
Magic Bytes
Unknown (Proprietary)
Portable Anymap
image/x-portable-anymap
Extension
.pnm
Container
Netpbm
Compression
Uncompressed
Algorithm
None
Color Depth
1-bit (PBM), 8-bit to 16-bit (PGM), 24-bit to 48-bit (PPM)
Developed by
Jef Poskanzer (Netpbm Project)
Released
1988
Magic Bytes
50 31, 50 32, 50 33, 50 34, 50 35, or 50 36
Browser Support Comparison
| Browser | FastBid | PNM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
FastBid
FastBid Strengths
- Historically allowed the FastBid application to securely associate and load proprietary construction plans within its ecosystem
Limitations
- Completely obsolete and unsupported in modern software environments
- The official IANA registration of the .fbs extension causes widespread false positives, breaking modern parsers, text editors, and AI SDKs attempting to read FlatBuffers schemas
PNM
PNM Strengths
- Unparalleled simplicity: parsers and writers for PNM files can be written from scratch in C or Python in just a few minutes without relying on external libraries
- Serves as an excellent foundational teaching tool for computer science students learning about image arrays and raster graphics
- Flawlessly pipes through Unix command-line utilities for robust automated image processing (via the Netpbm suite)
Limitations
- Zero compression natively results in astronomical file sizes, making it entirely impractical for web delivery or consumer storage
- No support for standard metadata formats like EXIF, XMP, or ICC color profiles
- No native alpha channel support in the classic PNM specification (though the newer PAM format 'P7' addresses this)
When to choose which format
FastBid
Use FastBid when…
- Legacy Construction Blueprints
- FastBid Estimating Software
- Causing .fbs MIME Type Conflicts (FlatBuffers)
PNM
Use PNM when…
- Unix/Linux Command-Line Image Processing (Netpbm suite)
- Academic Computer Vision Research
- Intermediary Format for Image Format Conversion