Image MIME Reference
PBM
Portable Bitmap
image/x-portable-bitmap
VS
Simple Vector Format
image/vnd.svf
SVF
A complete technical comparison of Portable Bitmap and Simple Vector Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | PBM | SVF |
|---|---|---|
| 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 |
Portable Bitmap
image/x-portable-bitmap
Extension
.pbm
Container
Netpbm
Compression
Uncompressed
Algorithm
None
Color Depth
1-bit (Monochrome)
Developed by
Jef Poskanzer (Netpbm Project)
Released
1988
Magic Bytes
50 31 (ASCII) or 50 34 (Binary)
Simple Vector Format
image/vnd.svf
Extension
.svf
Container
Custom Binary/Text (Legacy) or ZIP (Autodesk Forge)
Compression
Uncompressed / Deflate (in modern Autodesk SVF implementations)
Algorithm
None
Color Depth
Vector Data (Not Applicable)
Developed by
SoftSource & NCSA (National Center for Supercomputing Applications)
Released
1995
Magic Bytes
Unknown (SoftSource SVF)
Browser Support Comparison
| Browser | PBM | SVF |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
PBM
PBM Strengths
- Absolute structural simplicity allows parsers to be written from scratch with just a few lines of code
- ASCII encoding allows manual editing and debugging directly within a standard text editor
- Serves as a flawless, lossless intermediary for 1-bit raster data like scanned documents or barcodes
Limitations
- Strictly limited to 1-bit monochrome images; cannot natively display shades of gray or color
- Lack of compression results in extremely large file sizes, particularly when using the ASCII 'P1' encoding
- No support for alpha transparency or modern metadata standards like EXIF
SVF
SVF Strengths
- Acted as a crucial pioneering stepping-stone in proving that scalable, zoomable vector graphics were viable and necessary for the World Wide Web
Limitations
- Completely obsolete and unsupported by modern web standards
- Required end-users to install bulky, proprietary browser plugins
- Causes significant developer confusion today due to Autodesk adopting the exact same acronym and file extension for a completely different technology
When to choose which format
PBM
Use PBM when…
- Optical Character Recognition (OCR) Pre-processing
- Unix/Linux Command-Line Image Pipelines
- Academic Image Processing Teaching
SVF
Use SVF when…
- Historical Web-based CAD Viewers (1990s)
- Legacy 2D Vector Archival
- Autodesk Platform Services (Forge) Model Translation (Name Collision)