Image MIME Reference
J2C
JPEG 2000 Codestream
image/j2c
VS
Wireless Bitmap
image/vnd.wap.wbmp
WBMP
A complete technical comparison of JPEG 2000 Codestream and Wireless Bitmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | J2C | WBMP |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
JPEG 2000 Codestream
image/j2c
Extension
.j2c.j2k.jpc
Container
None (Raw Bitstream)
Compression
JPEG 2000 (Discrete Wavelet Transform) / Lossless / Lossy
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth
8-bit, 10-bit, 12-bit, 16-bit (Per Channel)
Developed by
Joint Photographic Experts Group (JPEG)
Released
2000
Magic Bytes
FF 4F FF 51
Wireless Bitmap
image/vnd.wap.wbmp
Extension
.wbmp
Container
WBMP Type 0
Compression
Uncompressed
Algorithm
None
Color Depth
1-bit (Monochrome)
Developed by
WAP Forum (Now Open Mobile Alliance)
Released
1999
Magic Bytes
00 00
Browser Support Comparison
| Browser | J2C | WBMP |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
J2C
J2C Strengths
- Provides state-of-the-art wavelet compression for high-end professional workflows (Digital Cinema)
- Allows for highly efficient progressive decoding (by resolution or quality layer) natively within the stream
- Supports lossless mathematical compression and high bit-depths (up to 16-bit per channel) natively
Limitations
- Lacks a standard container to store color space info or metadata, requiring external systems (like MXF or DICOM) to map colors correctly
- Extremely computationally expensive to encode and decode compared to standard DCT-based JPEG
- Zero web browser support
WBMP
WBMP Strengths
- Extremely low processing overhead made it perfectly suited for the ultra-low-power CPUs of late 1990s mobile devices
- Tightly integrated into the WML (Wireless Markup Language) stack, enabling the first functional mobile internet experiences
Limitations
- Completely obsolete and lacks support in modern operating systems and browsers
- Limited entirely to 1-bit black and white (0 for black, 1 for white) with zero support for grayscale, color, or transparency
- The lack of a strong file header signature makes automated MIME type detection highly unreliable
When to choose which format
J2C
Use J2C when…
- Digital Cinema Packages (DCP)
- Medical Imaging (DICOM Payloads)
- Professional Broadcast and Archiving
- Embedded Hardware Encoding
WBMP
Use WBMP when…
- Legacy WML (Wireless Markup Language) Mobile Sites
- Early Mobile Phone Icons and Operator Logos
- Historical WAP Archival