Image MIME Reference
DWG
AutoCAD Drawing
image/vnd.dwg
VS
JPEG 2000 Compound Image File Format
image/jpm
JPM
A complete technical comparison of AutoCAD Drawing and JPEG 2000 Compound Image File Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DWG | JPM |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
AutoCAD Drawing
image/vnd.dwg
Extension
.dwg
Container
DWG Binary Container
Compression
Proprietary Binary Compression (LZ77 based in newer versions)
Algorithm
Proprietary (Autodesk ObjectDBX)
Color Depth
Vector (True Color / Indexed AutoCAD Color Index)
Developed by
Autodesk
Released
1982
Magic Bytes
41 43 31 30 (AC10)
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 | DWG | JPM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DWG
DWG Strengths
- The undisputed industry standard for 2D drafting and basic 3D CAD modeling
- Highly optimized binary structure keeps file sizes relatively small compared to text-based CAD formats like DXF
- Supports incredibly complex datasets including external references (XREFs), dynamic blocks, and extensive custom metadata
Limitations
- It is a closed, proprietary format, making it difficult for third-party developers to support fully without licensing the Open Design Alliance (ODA) SDK
- Lacks native web or standard operating system previewer support
- Format versions change frequently (roughly every 3 years), breaking backward compatibility for older CAD software
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
DWG
Use DWG when…
- Architectural Floor Plans
- Mechanical Engineering Models
- Civil Engineering Drafts
- 3D Product Designs
JPM
Use JPM when…
- Scanned Document Archiving
- Mixed Raster Content (MRC) Imaging
- Digital Libraries