Image MIME Reference
JPEG
JPEG Image
image/jpeg
VS
JPEG 2000 Compound Image File Format
image/jpm
JPM
A complete technical comparison of JPEG Image and JPEG 2000 Compound Image File Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
JPEG wins on browser support
Feature Support
| Feature | JPEG | JPM |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | Yes |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
JPEG Image
image/jpeg
Extension
.jpg.jpeg.jpe.jfif
Container
JFIF / Exif
Compression
Lossy
Algorithm
DCT (Discrete Cosine Transform)
Color Depth
8-bit
Developed by
Joint Photographic Experts Group
Released
1992
Magic Bytes
FF D8 FF
JPEG 2000 Compound Image File Format
image/jpm
Extension
.jpm.jpgm
Container
ISOBMFF / JPM (ISO/IEC 15444-6)
Compression
Lossy / Lossless / Mixed Raster Content (MRC)
Algorithm
JPEG 2000JBIG2JPEGMMR
Color Depth
1-bit (Text/Masks), 8-bit, 16-bit, 24-bit
Developed by
Joint Photographic Experts Group (JPEG)
Released
2003
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 6D 20
Browser Support Comparison
| Browser | JPEG | JPM |
|---|---|---|
Chrome
|
✓ All
|
✕ |
Firefox
|
✓ All
|
✕ |
Safari
|
✓ All
|
✕ |
Edge
|
✓ All
|
✕ |
IE (Legacy)
|
✓
|
✕ |
JPEG
JPEG Strengths
- Universal support — every browser, OS, and application handles JPEG
- Excellent compression for complex photographs with natural color gradients
- Rich metadata support: EXIF (GPS, camera settings), ICC color profiles
Limitations
- No transparency — cannot have a transparent background
- Lossy compression introduces visible artifacts on sharp edges and text
- No animation support
JPM
JPM Strengths
- Highly optimized for scanned documents, drastically reducing file sizes without sacrificing the readability of text or the quality of embedded photos
- Supports multi-page documents within a single file
- Object-based architecture allows for complex layout representation and independent extraction of elements
Limitations
- Failed to achieve widespread adoption, largely being overshadowed by PDF/A and DjVu
- Zero native web browser compatibility
- Requires complex, specialized software to properly encode and decode the multi-layered MRC structure
When to choose which format
JPEG
Use JPEG when…
- Photography
- Websites
- Social Media
JPM
Use JPM when…
- Scanned Document Archiving
- Mixed Raster Content (MRC) Imaging
- Digital Libraries