Image MIME Reference
BTIF
Bank Telecommunications Image Format
image/prs.btif
VS
Portable Graymap
image/x-portable-graymap
PGM
A complete technical comparison of Bank Telecommunications Image Format and Portable Graymap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | BTIF | PGM |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
Bank Telecommunications Image Format
image/prs.btif
Extension
.btif.btf
Container
Proprietary Check Image Container
Compression
Lossy (JPEG-based) / Lossless (TIFF-based)
Algorithm
JPEGTIFF-variant
Color Depth
1-bit (B&W), 8-bit (Grayscale)
Developed by
NationsBank (Bank of America) / Ben Simon
Released
1998
Magic Bytes
Unknown (Proprietary container)
Portable Graymap
image/x-portable-graymap
Extension
.pgm
Container
Netpbm
Compression
Uncompressed
Algorithm
None
Color Depth
8-bit (Grayscale), 16-bit (Grayscale)
Developed by
Jef Poskanzer (Netpbm Project)
Released
1988
Magic Bytes
50 32 (ASCII) or 50 35 (Binary)
Browser Support Comparison
| Browser | BTIF | PGM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
BTIF
BTIF Strengths
- Allowed early digital archiving and web-based transmission of cleared bank checks
- Encapsulated both image data and ASCII transaction metadata in a single file
Limitations
- Completely proprietary and obsolete format
- Lacks native support in modern operating systems and image viewers
- Requires legacy plugins or specialized bio-format readers (like ImageC) to decode
PGM
PGM Strengths
- Extremely simple format allows custom parsers to be written from scratch in minimal time
- Supports 16-bit precision, making it highly valuable for scientific, medical, and height-map data where 8-bit precision is insufficient
- ASCII encoding ('P2') allows manual editing and visual inspection of pixel values directly within a text editor
Limitations
- Strictly limited to grayscale; cannot display color
- Lack of compression results in massive file sizes, making it entirely impractical for web delivery or consumer storage
- Does not support alpha transparency or modern metadata structures
When to choose which format
BTIF
Use BTIF when…
- Bank Check Archiving (Legacy)
- Financial Transaction Records
PGM
Use PGM when…
- Computer Vision and Machine Learning Pre-processing
- Scientific and Medical Image Processing
- Unix/Linux Command-Line Image Pipelines